Science

[AU's] [Aquifers] [Amino Acids] [Asteroids] [Atmosphere] [Calderas] [Canyons] [Cern] [Comets] [Continents] [CT Scanning]

[DNA] [Dimensions] [Deserts] [Doppler Effect] [Our Earth] [Epicenter] [Faults] [Flooding] [Galaxies] [Genomes] [Geologic Terms]

[Global Warming] [Gravity] [Hail] [Hurricanes] [Double Helix] [Lahar] [Landslides] [Lasers] [Lightning]

[ [

[Rivers] [Rogue Waves] [Seas & Lakes] [Tephra] [Tornadoes] [Trivia] [Tsunamis] [Seismic Waves] [Our Sun] [Solar System]

[Ultrasound] [Volcanoes] [Weather/Storms] [Wind] [X-Ray]

AMINO ACIDS
Amino acids are the building blocks (monomers) of proteins

Two individual amino acids can be linked to form a larger molecule, with the loss of a water molecule as a by-product of the reaction.

 alanine  arginine  asparagine aspartic acid  cysteine glutamine glutamic acid glycine  histidine  isoleucine leucine  lysine methionine  phenylalanine  proline  serine  threonine  tryptophan  tyrosine valine

Water (H2o) expands its volume by 9% upon freezing.

AQUIFERS

ASTEROIDS

ATMOSPHERE OF EARTH

At present the composition of our atmosphere is 79% nitrogen, 20% oxygen, and 1% other gases.
Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity.

The Air pressure at sea level, the air pressure is about 14.7 pounds per square inch. As you climb in altitude, the air pressure decreases. At an altitude of 10,000 feet, the air pressure is 10 pound per square inch (and there is less oxygen to breathe).  Conversely, when you travel down into the earth, the pressure increases, as well as the heat..

### The Troposphere

The troposphere is the lowest region in the Earth's atmosphere. On the Earth, it goes from ocean (ground) level up to about 11 miles high. The weather and clouds occur in the troposphere. In the troposphere, the temperature generally decreases as altitude increases. is where all weather takes place; it is the region of rising and falling packets of air. The air pressure at the top of the troposphere is only 10% of that at sea level (0.1 atmospheres). There is a thin buffer zone between the troposphere and the next layer called the tropopause.

### The Stratosphere and OzoneLayer

Above the troposphere is the stratosphere which extends between 11 and 31 miles above the earth's surface, and here air flow is mostly horizontal. The thin *ozone layer in the upper stratosphere has a high concentration of ozone, a particularly reactive form of oxygen. This layer is primarily responsible for absorbing the ultraviolet radiation from the Sun. The formation of this layer is a delicate matter, since only when oxygen is produced in the atmosphere can an ozone layer form, and prevent an intense flux of ultraviolet radiation from reaching the surface, where it is quite a hazard to mankind, and animals alike.

The largest average area ever recorded was 26.5 million square kilometers, recorded in 2000. The year 2000 also saw the largest area on a given date: 29 million square kilometers. It is mainly located in the lower portion of the stratosphere from approximately 15 km to 35 km above Earth's surface, though the thickness varies seasonally and geographically.  Ten percent of the ozone in the atmosphere is contained in the troposphere, the lowest part of our atmosphere where all of our weather takes place. Tropospheric ozone has two sources: about 10 % is transported down from the stratosphere while the remainder is created in smaller amounts through different mechanisms.

There is less ozone over the equator than over other parts of the world. The average thickness is about 300 DU (Dobson Units), which equals a three millimeter (or 0.12") thick layer cloud of compressed ozone. Obviously, the ozone layer is really thin!

The concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation emitted from the Sun. At present there is considerable concern that man made flourocarbon compounds may be depleting the ozone (There was no ozone 650 millions year ago) layer, with dire future consequences for life on the Earth. Interestingly, Ozone found in the lowest levels of the atmosphere can have harmful effects on humans. People with asthma or other breathing problems are especially prone to its effects.

Most ozone found in our atmosphere is formed by an interaction between oxygen molecules and ultraviolet radiation emitted by the sun. Oxygen molecules make up about 21% of all gases in the earth's atmosphere; consisting of two atoms of oxygen and are therefore labeled O2. Instead of being made up of 2 atoms it contains 3 atoms.

Without the Ozone, we would most likely perish in time.

*The ozone layer was discovered by the French physicists Charles Fabry and Henri Buisson in 1913.

### The Mesosphere

The mesosphere is characterized by temperatures that quickly decrease as height increases. The mesosphere extends from between 31 and 50 miles above the earth's surface.

### Ionosphere

The ionosphere (or thermosphere), starts at about 43-50 miles high and continues for hundreds of miles (about 400 miles). where many atoms are ionized (have gained or lost electrons so they have a net electrical charge). The ionosphere is very thin, but it is where aurora take place, and is also responsible for absorbing the most energetic photons from the Sun, and for reflecting radio waves, thereby making long-distance radio communication possible.

The structure of the ionosphere is strongly influenced by the charged particle wind from the Sun (solar wind), which is in turn governed by the level of Solar activity. One measure of the structure of the ionosphere is the free electron density, which is an indicator of the degree of ionization.

 The term AU is the Astronomical unit of measurement referred to for the solar system. The distance from Earth to our Sun (93,000,000 miles) is one AU, the end of the Milky Way Galaxy being about fifty thousand AU's. A light year is 10,000,000,000,000 kilometers, an enormous distance.

CANYONS OF THE WORLD
(Over 500 Meters)

 The word canyon is generally used in the United States, while the word gorge is more common in Europe and Oceania, though it is also used in some parts of the United States and Canada
 Name Depth Country Batopilas Canyon 5,904 m MX Colca Canyon 3,269' ( Average. 3,400 m) Peru Columbia River Gorge 4,000' (1,300 m) US Copper Canyon 5,770 m MX Cotahuasi Gorge 3,354 m Peru Fish River Canyon 500 m Aftrica Grand Canyon (US) 4,674' US Hells Canyon 7,993' (2,436 m) US Iron Gate Gorge 500 m Romania/Serbia Joseph Canyon 2,000' US Kali Gandaki Gorge 1,301-2,600 m Nepal Kings Canyon 8,200' ( 2,400 m) US Mariana Trench (Worlds deepest underwater trench) 6.8 miles (11,000 m) Marianas Islands Nazare Canyon 5,000 m Portugal Samaria Gorge 1,250 m Isle of Crete Sin Forosa Canyon 5,904 m MX Taraecuz Canyon 4,674 m MX Tekeze Gorge 2,000 m Africa Urique Canyon 6,136 m MX Vikos Gorge 1,000 m Greece Yarlung Tsangpo Gorge 16,659' (5,382 m) Tibet Zhemchug Canyon (Underwater canyon) 2,600 m Bering Sea

 CLOUDS Description of Cloud types: High-Level Clouds Cloud types include: cirrus and cirrostratus. -These form above 20,000 feet (6,000 meters) and since the temperatures are so cold at such high elevations, these clouds are primarily composed of ice crystals. High-level clouds are typically thin and white in appearance, but can appear in a magnificent array of colors when the sun is low on the horizon. Mid-Level Clouds Cloud types include: altocumulus, altostratus. -Typically appear between 6,500 to 20,000 feet (2,000 to 6,000 meters). Because of their lower altitudes, they are composed primarily of water droplets, however, they can also be composed of ice crystals when temperatures are cold enough. Low-Level Clouds Cloud types include: nimbostratus and stratocumulus. -Mostly composed of water droplets since their bases generally lie below 6,500 feet (2,000 meters). However, when temperatures are cold enough, these clouds may also contain ice particles and snow. Clouds with Vertical Development Cloud types include: fair weather cumulus and cumulonimbus. -The cumulus cloud is generated most commonly through either thermal convection or frontal lifting; these clouds can grow to heights in excess of 39,000 feet (12,000 meters), releasing incredible amounts of energy through the condensation of water vapor within the cloud itself. Other Cloud Types Cloud types include: Contrails (also known as a condensation trail, is a cirrus-like trail of condensed water vapor often resembling the tail of a kite. Contrails are produced at high altitudes where extremely cold temperatures freeze water droplets in a matter of seconds before they can evaporate. Often exhaust fumes from a jet engine. If the surrounding air is cold enough, a state of saturation is attained and ice crystals develop, producing a contrail.), Billow clouds ( Billow clouds are created from instability associated with air flows having marked vertical shear and weak thermal stratification), mammatus (Mammatus are pouch-like cloud structures and a rare example of clouds in sinking air, usually seen after the worst of a thunderstorm has passed), orographic (When air is confronted by a mountain, it is lifted up and over the mountain, cooling as it rises. If the air cools to its saturation point, the water vapor condenses and a cloud forms), and pileus cloud ( is a smooth cloud found attached to either a mountain top or growing cumulus tower). The lowest part of the Clouds are visible accumulations of water droplets or solid ice crystals that float in the Earth's troposphere  Earth's atmosphere), moving with the wind. From space, clouds are visible as a white veil surrounding the planet. Clouds form when water vapor (water that has evaporated from the surface of the Earth) condenses (turns into liquid water or solid ice) onto microscopic dust particles (or other tiny particles) floating in the air. This condensation (cloud formation) happens when warm and cold air meet, when warm air rises up the side of a mountain and cools as it rises, and when warm air flows over a colder area, like a cool body of water. This occurs because cool air can hold less water vapor than warm air, and excess water condenses into either liquid or ice. Water vapor and particles in the air such as dust or sea spray. If the air is saturated with water, the water vapor can condense into droplets or be deposited as ice crystals around the particles. A collection of billions of these tiny droplets or ice crystals forms a cloud. A mass of air can become saturated with water when it is uplifted and cooled. Air is uplifted by a number of different processes, including orographic ascent, convection, and convergence. Orographic ascent takes place when the shape of the landscape forces air upward; convection occurs when air at ground level is heated by Earth's surface, becomes less dense, and then rises up through the cooler, denser air above it; and convergence happens when two air masses meet, forcing one of them upward. While most clouds are produced by uplift, some clouds are formed when water vapor is added to the air, for example, due to exhaust from an airplane. Clouds continuously shift and change shape because of air movement. They dissipate as the water droplets evaporate or move apart from each other. Winds also carry clouds across the sky. Because different levels of the atmosphere have different winds, it is possible to see clouds that are at different levels moving at different speeds. If you watch clouds over a period of time, you will likely see them forming, moving, and changing shape. These clouds can float because they are warmer that their surrounding environment. Clouds do not move by themselves. They are carried away by the winds that prevail at the cloud level. The speed and direction of the winds change from layer to layer in the atmosphere un to great heights. Sometimes a jet stream will be blowing over our head with a speed more than a hurricane and we may not be aware of it. So clouds move very fast when the wind is strong at the cloud-base level. Even when the clouds move very fast, they may seem to move slowly when its height is more. Low-level cloud seems to move fast even if its speed is less. For example, the stratus which forms nearest to the surface always seems to move very fast.

## Comets

 When looking at the night sky and you observe a comet, it will appear to move very slowly, when in fact it is hurtling through space at several thousands of miles per hour. This is because very few of them come within a few million miles of Earth and so the huge distance makes them appear very slow. Also at times the comet is coming towards us or moving away from so and us might even appear stationary. Comets are generally visible for periods ranging from a few days to several months, and appear to change little in position night-after-night Comets are sometimes called "dirty snowballs" because they are mixtures of ices and dust. The comets have a core or a nucleus, made up of mainly ice and dust, and is frozen solid. In this state they only reflects light and so are generally invisible in the far outreaches of the solar system, it is only when they approach the sun, do they become luminous. As comet nears the sun, the nucleus begins to warm up and some of the ice begins to evaporate, these gases carry dust particles along with them and create the coma, that envelope the nucleus in a cloud of gas and dust. The dust reflects still more light; while the gases absorb ultraviolet rays and begin to glow. As they get closer to the sun, the comets develop tails of radiant material that stretches into millions of kilometers. The tail always faces away from the sun and is shaped by the solar winds as well as the radiation emitted by the sun. What is really interesting is that comets can sometimes split their tails; they can even have multiple tails and can even lose the tails at times. Comets are divided into two types by the period of their orbit: short period comets complete their orbit in 200 or less years and long period comets take more than 200 years to orbit the Sun. Of the two types, short period comets have less elliptical orbits. Short period comets, like asteroids and meteoroids, are left over bits that were never incorporated into a planet during planet formation. The Kuiper Belt, which is 30-100 AU from the Sun, is a reservoir of these short period comets. During the formation of the Solar System, the Kuiper belt was on the outer part of the pre-planetary disk. Since the part of the disk was less dense than the inner part, only small comets could be formed, not large outer planets. Long period comets, which have very elliptical orbits, usually originate from the Oort Cloud. Occasionally, a star passes by the Oort Cloud and disturbs the orbits of the comets within it. Some of these comets change course and enter the Solar System. Comets are composed of dust and ices. The ices contained by comets include water, methane, ammonia, and carbon dioxide. These ices are sublimed off the nucleus when the comet nears the Sun. A dust tail, which is the part of a comet easiest to see, forms from dust particles that are driven off the nucleus by escaping gases and plasma. An ion tail, which can be as long as 2 AU when the comet is near the Sun, forms from plasma that interacts with the solar wind. In addition, a coma forms around the nucleus. A coma is a large, bright cloud of gases and dust ejected from the nucleus. Meteoroids, Meteors, and Meteorites: Meteors are small rocks, sometimes as fine as grains of sand. When these meteors enter the earth’s atmosphere, due to friction, they get heated up, and make the air around them glow. They last for only a few seconds before completely disintegrating and are commonly known as shooting stars. Some of them might be big enough to reach the earth’s surface and are called meteorites. Meteors enter the Earth's atmosphere on a regular basis and on most nights you can see a few meteors per hour. During meteor showers, however, meteors are visible at a much higher rate. Meteor showers are usually associated with comets. Comets cast off debris when they near the Sun and when Earth passes through the debris; its sky displays astonishing meteor showers. It is also assumed that early collisions between earth and comets resulted in the vast amounts of water that now make up 3/4th of the earth’s surface. It is only because of these waters that life on earth was possible, so in that sense we possibly owe all our waters and therefore our lives to these brilliant comets.

 COMPUTERS Inventors of the First Computer: (Atanasoff-Berry Computer"ABC") In the mid-1930s, a professor of physics and mathematics at Iowa State College named John Vincent Atanasoff began work on a machine capable of solving complex sets of linear algebraic equations. In doing so, he and his graduate-student assistant Clifford Berry explored many of the techniques and technologies that later became widely adopted in electronic computing: the use of binary arithmetic based on logical rather than counting principles; periodically regenerating rotating drum memory; the separation of memory and arithmetic units; the automatic coordination of operations through a centralized "clock." Although the Atanasoff-Berry Computer (ABC) was never fully completed, and Atanasoff himself soon moved on to other projects, the ABC nevertheless represented a pioneering milestone in the development of the modern computer.

 CRACKING (The Process of REFINING PETROLEUM)

 Petroleum is a complex mixture of organic liquids called crude oil and natural gas, which occurs naturally in the ground and was formed millions of years ago, and every refinery begins with the separation of crude oil into different fractions by distillation. These are processes that allow the production of "light" products such as LPG and gasoline from heavier crude oil distillation fractions such as gas oils and residues. Fluid catalytic cracking produces a high yield of gasoline and LPG, while hydrocracking is a major source of jet fuel, diesel, naphtha and LPG. An oil refinery is an organized and coordinated arrangement of manufacturing processes designed to produce physical and chemical changes in crude oil to convert it into everyday products like gasoline, diesel, lubricating oil, fuel oil and bitumen. As crude oil comes from the well it contains a mixture of hydrocarbon compounds and relatively small quantities of other materials such as oxygen, nitrogen, sulphur, salt and water. In the refinery, most of these non - hydrocarbon substances are removed and the oil is broken down into its various components, and blended into useful products. Natural gas from the well, while principally methane, contains quantities of other hydrocarbons - ethane, propane, butane, pentane and also carbon dioxide and water. These components are separated from the methane at a gas fractionation plant. The three main hydrocarbon groups: Paraffinic: These consist of straight or branched carbon rings saturated with hydrogen atoms, the simplest of which is methane ($CH$4) the main ingredient of natural gas Naphthenic: These consist of carbon rings, sometimes with side chains, saturated with hydrogen atoms. Naphthenes are chemically stable, they occur naturally in crude oil and have properties similar to paraffin’s Aromatic. These hydrocarbons are compounds that contain a ring of six carbon atoms with alternating double and single bonds and six attached hydrogen atoms. This type of structure is known as a benzene ring. They occur naturally in crude oil, and can also be created by the refining process

DNA-RNA

 The nucleic acids are very large molecules that have two main parts. The backbone of a nucleic acid is made of alternating sugar and phosphate molecules bonded together in a long chain There are four different nucleodites bases which can occur in nucleic acid, each nucleic acid contains millions of bases bonded to it. The order in which these nucleotide bases appear in the nucleic acid is the coding for the information carried in the molecule. In other words, the nucleotide bases serve as a sort of genetic alphabet on which the structure of each protein in our bodies is encoded.

Deoxyribonucleic acid or DNA:

DNA is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).

The information in DNA is stored as a code made up of four chemical bases:

adenine , cytosine, guanine , and thymine

Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.

The high molecular weight nucleic acid, DNA, is found chiefly in the nuclei of complex cells, known as eucaryotic cells, or in the nucleoid regions of procaryotic cells, such as bacteria. It is often associated with proteins that help to pack it in a usable fashion.

Not only is the DNA molecule double-stranded, but the two strands wrap around each other forming a coil, or helix. The true structure of the DNA molecule is a double helix. This unique double-stranded DNA molecule has the unique ability to make exact copies of itself, or self-replicate. When more DNA is required by an organism (such as during reproduction or cell growth) the hydrogen bonds between the nucleotide bases break and the two single strands of DNA separate. New complementary bases are brought in by the cell and paired up with each of the two separate strands, thus forming two new, identical, double-stranded DNA molecules.

 RNA In contrast RNA is of a  lower molecular weight, and is much more abundant in nucleic acid, RNA, is distributed throughout the cell, most commonly in small numerous organelles called ribosomes. Ribonucleic acid, or RNA, gets its name from the sugar group in the molecule's backbone - ribose. Several important similarities and differences exist between RNA and DNA. Like DNA, RNA has a sugar-phosphate backbone with nucleotide bases attached to it. Like DNA, RNA contains the bases adenine (A), cytosine (C), and guanine (G); however, RNA does not contain thymine, instead, RNA's fourth nucleotide is the base uracil (U). Unlike the double-stranded DNA molecule, RNA is a single-stranded molecule. RNA is the main genetic material used in the organisms called viruses, and RNA is also important in the production of proteins in other living organisms. RNA can move around the cells of living organisms and thus serves as a sort of genetic messenger, relaying the information stored in the cell's DNA out from the nucleus to other parts of the cell where it is used to help make proteins.

 GENOMES <>Life is specified by genomes. Every organism, including humans, has a genome that contains all of the biological information needed to build and maintain a living example of that organism. The biological information contained in a genome is encoded in its deoxyribonucleic acid (DNA) and is divided into discrete units called genes. Genes code for proteins that attach to the genome at the appropriate positions and switch on a series of reactions called gene expression. The genome of an organism is a complete genetic sequence on one set of chromosomes; for example, one of the two sets that a diploid individual carries in every somatic cell. The term genome can be applied specifically to mean that stored on a complete set of nuclear DNA (i.e., the "nuclear genome") but can also be applied to that stored within organelles that contain their own DNA, as with the mitochondrial genome or the chloroplast genome. When people say that the genome of a sexually reproducing species has been "sequenced," typically they are referring to a determination of the sequences of one set of autosomes and one of each type of sex chromosome, which together represent both of the possible sexes. Even in species that exist in only one sex, what is described as "a genome sequence" may be a composite read from the chromosomes of various individuals? In general use, the phrase "genetic makeup" is sometimes used conversationally to mean the genome of a particular individual or organism. The study of the global properties of genomes of related organisms is usually referred to as genomics, which distinguishes it from genetics which generally studies the properties of single genes or groups of genes.

DOPPLER EFFECT

Named after Austrian physicist Christian Doppler

 We have all experienced it, most commonly it is heard when one is at a train crossing, as the train horn is sounded, or one hears it when a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.   The Doppler represents the shift in frequency and wavelength of waves which results from a source moving with respect to the medium, a receiver moving with respect to the medium, or even a moving medium.   The perceived frequency (f ´) is related to the actual frequency (f0) and the relative speeds of the source (vs), observer (vo), and the speed (v) of waves in the medium.    The choice of using the plus (+) or minus (-) sign is made according to the convention that if the source and observer are moving towards each other the perceived frequency (f ´) is higher than the actual frequency (f0). Likewise, if the source and observer are moving away from each other the perceived frequency (f ´) is lower than the actual frequency (f0). For waves that propagate in a medium, such as sound waves, the velocity of the observer and of the source are relative to the medium in which the waves are transmitted. The total Doppler effect may therefore result from motion of the source, motion of the observer, or motion of the medium. Each of these effects is analyzed separately. For waves which do not require a medium, such as light or gravity in general relativity, only the relative difference in velocity between the observer and the source needs to be considered.   Although first discovered for sound waves, the Doppler effect holds true for all types of waves including light (and other electromagnetic waves). The Doppler effect for light waves is usually described in terms of colors rather than frequency.   The Doppler effect for electromagnetic waves such as light is of great use in astronomy results in either a so-called redshift or blue shift. It has been used to measure the speed at which stars and galaxies are approaching or receding from us, that is, the radial velocity. This is used to detect if an apparently single star is, in reality, a close binary and even to measure the rotational speed of stars and galaxies. The use of the Doppler effect for light in astronomy depends on our knowledge that the spectra of stars are not continuous.   They exhibit absorption lines at well defined frequencies that are correlated with the energies required to excite electrons in different elements from one level to another. The Doppler effect is recognizable in the fact that the absorption lines are not always at the frequencies that are obtained from the spectrum of a stationary light source. Since blue light has a higher frequency than red light, the spectral lines of an approaching astronomical light source exhibit a blue shift and those of a receding astronomical light source exhibit a redshift.   The Doppler effect is used in some types of radar, to measure the velocity of detected objects. A radar beam is fired at a moving target — e.g. a motor car, as police use radar to detect speeding motorists — as it approaches or recedes from the radar source. Each successive radar wave has to travel farther to reach the car, before being reflected and re-detected near the source. As each wave has to move farther, the gap between each wave increases, increasing the wavelength. In some situations, the radar beam is fired at the moving car as it approaches, in which case each successive wave travels a lesser distance, decreasing the wavelength

 DIMENSIONS (Three) That there are three dimensions seems to be an irrefutable fact. Fact is,  we can only move up or down, left or right, in or out, but the Randall-Sundrum "braneworld" gravity type II model theory holds that the visible universe is a membrane (hence "braneworld") embedded within a larger universe, much like a strand of filmy seaweed floating in the ocean. The "braneworld universe" has five dimensions -- four spatial dimensions plus time -- compared with the four dimensions -- three spatial, plus time -- laid out in the General Theory of Relativity. (Four) If the braneworld theory proves to be true, "this would upset the applecart,"according to Arlie O. Petters of Duke. "It would confirm that there is a fourth dimension to space, which would create a philosophical shift in our understanding of the natural world." The scientists' findings appeared May 24, 2006, in the online edition of the journal Physical Review D. Keeton is an astronomy and physics professor at Rutgers, and Petters is a mathematics and physics professor at Duke. Their research is funded by the National Science Foundation. The Randall-Sundrum braneworld model -- named for its originators, physicists Lisa Randall of Harvard University and Raman Sundrum of Johns Hopkins University -- provides a mathematical description of how gravity shapes the universe that differs from the description offered by the General Theory of Relativity. Keeton and Petters focused on one particular gravitational consequence of the braneworld theory that distinguishes it from Einstein's theory. The braneworld theory predicts that relatively small "black holes" created in the early universe have survived to the present. The black holes, with mass similar to a tiny asteroid, would be part of the "dark matter" in the universe. As the name suggests, dark matter does not emit or reflect light, but does exert a gravitational force. The General Theory of Relativity, on the other hand, predicts that such primordial black holes no longer exist, as they would have evaporated by now. "When we estimated how far braneworld black holes might be from Earth, we were surprised to find that the nearest ones would lie well inside Pluto's orbit," Keeton said. Petters added, "If braneworld black holes form even 1 percent of the dark matter in our part of the galaxy -- a cautious assumption -- there should be several thousand braneworld black holes in our solar system." But do braneworld black holes really exist -- and therefore stand as evidence for the 5-D braneworld theory? The scientists showed that it should be possible to answer this question by observing the effects that braneworld black holes would exert on electromagnetic radiation traveling to Earth from other galaxies. Any such radiation passing near a black hole will be acted upon by the object's tremendous gravitational forces -- an effect called "gravitational lensing." "A good place to look for gravitational lensing by braneworld black holes is in bursts of gamma rays coming to Earth," Keeton said. These gamma-ray bursts are thought to be produced by enormous explosions throughout the universe. Such bursts from outer space were discovered inadvertently by the U.S. Air Force in the 1960s. Keeton and Petters calculated that braneworld black holes would impede the gamma rays in the same way a rock in a pond obstructs passing ripples. The rock produces an "interference pattern" in its wake in which some ripple peaks are higher, some troughs are deeper, and some peaks and troughs cancel each other out. The interference pattern bears the signature of the characteristics of both the rock and the water. Similarly, a braneworld black hole would produce an interference pattern in a passing burst of gamma rays as they travel to Earth, said Keeton and Petters. The scientists predicted the resulting bright and dark "fringes" in the interference pattern, which they said provides a means of inferring characteristics of braneworld black holes and, in turn, of space and time. "We discovered that the signature of a fourth dimension of space appears in the interference patterns," Petters said. "This extra spatial dimension creates a contraction between the fringes compared to what you'd get in General Relativity." Petters and Keeton said it should be possible to measure the predicted gamma-ray fringe patterns using the Gamma-ray Large Area Space Telescope, which is scheduled to be launched on a spacecraft in August 2007. The telescope is a joint effort between NASA, the U.S. Department of Energy, and institutions in France, Germany, Japan, Italy and Sweden. The scientists said their prediction would apply to all braneworld black holes, whether in our solar system or beyond. "If the braneworld theory is correct," they said, "there should be many, many more braneworld black holes throughout the universe, each carrying the signature of a fourth dimension of space." Source: Duke University (Fifth) Abstract five-dimensional space occurs frequently in mathematics, and is a perfectly legitimate construct. Whether or not the real universe in which we live is somehow five-dimensional is a topic that is debated and explored in several branches of physics, including astrophysics and particle physics. Dimensions. Some scientists have speculated that the In physics, the Fifth dimension is a hypothetical extra dimension beyond the usual three spatial and one timegraviton, a particle thought to carry the force of gravity, may "leak" into the fifth or higher dimensions which would explain how gravity is significantly weaker than the other three fundamental forces. In 2006 and alternate theory was proposed by Martin Davies, which states that judging by the 3 spatial dimensions, and their counterpart, time, which allows movement around the 3 spatial dimensions, the 5th, 6th or a higher, dimension may be a 'time travel dimension' allowing the traversal of time. (More) According to P. D. Ouspensky, In Search of the Miraculous:  "Every moment of time contains a certain number of possibilities, at times a small number, at others a great number, but never an infinite number. It is necessary to realize that there are possibilities and impossibilities. I can take from this table and throw on the floor a piece of paper, a pencil, or an ash-tray, but I cannot take from the table and throw on the floor an orange which is not on the table. This clearly defines the difference between possibility and impossibility. There are several combinations of possibilities in relation to things which can be thrown on the floor from this table. I can throw a pencil, or a piece of paper, or an ashtray, or else a pencil and a piece of paper, or a pencil and an ashtray, or a piece of paper and an ash-tray, or all three together, or nothing at all. There are only these possibilities. If we take as a moment of time the moment when these possibilities exist, then the next moment will be a moment of the actualization of one of these possibilities. A pencil is thrown on the floor. This is the actualization of one of the possibilities. Then a new moment comes. This moment also has a certain number of possibilities in a certain definite sense. And the moment after it will again be a moment of the actualization of one of these possibilities [...] But all the possibilities that have been created or have originated in the world must be actualized [...] The sixth dimension is the line of the actualization of all possibilities."

 QT. Geology is named after Gaea, the daughter of Chaos.

 Did you know that there is no evidence in fossil sediments of Homo Sapiens beyond the last Ice Age?

GEOLOGIC TIME TABLE

 Eon Era Period Epoch Age at Start Phanerozoic Cenozoic Quaternary Holocene 10,000 yrs. Before present. Pleistocene (first modern man) 2 mil. bp Tertiary Pliocene (first man) 5 mil bp Miocene 24 mil. bp Oligocene 37 mil bp Eocene 58 mil bp Paleocene (first horses) 65 mil bp/extinction of the dinosaurs Mesozoic Cretaceous (beginning of the end of dinosaurs) 144 mil bp Jurassic (first birds) 208 mil bp Triassic (Dinosaurs & Mammals) 245 mil bp Paleozoic Permian  (extinction of Trilobites) 286 mil bp Pennsylvanian (coniferous plants) 320 mil bp Mississippian (first reptiles) 360 mil bp Devonian (first Amphibians) 408 mil bp Silurian (land plants) 438 mil bp Ordovician (Millipedes) 505 mil bp Cambrian (first  fisher) 570 mil bp Precambrian Proterozoic 2,500 mil bp Archean 3,800 mil bp Hadean 4,600 mil. bp + OR - 70,000 yrs.

PLANET EARTH

"Terra"

The Planet Earth is 4.600 Billion Years old, + or - 70 million years. (although no physical evidence of age beyond 3.5 billion years has been discovered)
Life began on the Planet 135 millions before the present (BP) at the end of the last Big Freeze.

The tilt of axis (degrees) is 23.45

Earth travels at the speed of 108,000 kilometers (67,000 miles) an hour.

Earth is the 3rd planet from the Sun at a distance of about 150 million kilometers (93.2 million miles). It takes 365.256 days for the Earth to travel around the Sun and 23.9345 hours for the Earth rotate a complete revolution. It has a diameter of 12,756 kilometers (7,973 miles), Earth’s atmosphere is composed of 78 percent nitrogen, 21 percent oxygen and 1 percent other constituents.

Earth is the only planet in the solar system known to harbor life. Our planet's rapid spin and molten nickel-iron core give rise to an extensive magnetic field, which, along with the atmosphere, shields us from nearly all of the harmful radiation coming from the Sun and other stars. Earth's atmosphere protects us from meteors, most of which burn up before they can strike the surface.

There is geological evidence to suggest that the geophysical poles of the earth have shifted many times in the past. These previous pole shifts explain some of the mystery surrounding such past events as the sudden extinction of the dinosaurs, or the sudden changes in global climate. There is no clear evidence that these were all caused by asteroid collision. These things reflect changes as the result of periodic pole shifts brought on by disturbances within the earth as caused by disturbances in the sun.

The core of the earth is nearly as hot as the sun. Magma convection currents rise from the Earth' center towards the surface and sink again as they cool. The core of the earth having a smaller diameter spins faster than the exterior of the globe. This causes a twisting of the soft magma as it spirals out from the center to the surface. This twisting spiral surrounding a spinning iron core acts as an electric dynamo. Massive voltages of electric current are generated and flow between positive and negative poles. The magnetic field that surrounds the earth is produced by the electric current flowing within the planet

Dating the Earth::

- Isotopes measure Nuclei decay/ half life’s.

If you know the half-life of a given radioactive element, you can in principle use the decay of that radionuclide as a clock to measuer a time interval. This clock, however, doesn't go 1, 2, 3, ... in fact it goes more like 1, 2, 4, 8, ... The decay of very long-lived nuclides, can be used to measure the age of rocks, that is, the time that has elapsed since they were formed. Measurements for rocks from the Earth and the moon yield a consistent age of about 4.5 X 109 years.

For measuring shorter time intervals, in the range of historical interest, radiocarbon dating has proved invaluable. The radionuclide Carbon (with half-life of 5730 years) is produced at a constant rate in the upper atmosphere. This radiocarbon mixes with the carbon that is normally present in the atmosphere so that there is about one atom of Carbon for every 1013 atoms of ordinary Carbon. The atmospheric carbon exchanges with the carbon in every living thing on Earth, including humans, so that all living things contain a small fixed fraction of the Carbon nuclide.

This exchange persists as long as the organism is alive. After the organism dies, the exchange with the atmosphere stops and the amount of radiocarbon trapped in the organism, since it is no longer being replenished, dwindles away with a half-life of 5730 years. By measuring the amount of radiocarbon per gram of organic matter, it is possible to measure the time that has elapsed since the organism died.

-Carbon 14 is formed as nirogen bomarded by cosmic rays. It only measures organic material younger than 70,000 years.

How Old is it?

TREES: Tree Rings 'Growth Rings'  l per year. The rings also reflect the seasonal changes by the size of the rings. The Bristlecone Pines of the Southwest and Eastern California date back thousands of years.

SOIL: Varves. annual sediment layers, also reflect seasonal changes and, therefore, record time. The best-known varves are those laid down in lake formed by the damming of glacial melt-water. Each varve consists of a lighter, thicker, coarser summer layer and a darker, thinner, finer layer deposited during ice-covered periods. You simply count the couplets of beds for the span of a lake's existence. Varve counts of glacial lake sediments that relate to the last glaciations give values of about 15,000 years; those of certain older, nonglacial lakes give their duration as a few million years.

The Continents :

Africa, Antarctica, Asia, Australia, Europe, North America, and South America

The Deserts of our World:
Arabian - covering most of the Arabian peninsula.
Atacama - running down the western coast of South America.
Australian - hot deserts covering much of western and central Australia.
Iranian - northeast of the Arabian peninsula and west of the Thar desert.
Kalahari - covering much of the southeastern tip of Africa.
Namib - running down the southwestern coast Africa.
North American - in southwestern North America, pin the USA and Mexico.
Patagonian - in southeastern South America.
Saharan - a huge desert covering much of northern Africa.
Takla Makan-Gobi - in eastern China.
Thar - in northwest India.
Turkestan - in southern Russia .

The different Eras are marked by major life extinctions in the fossil records, including the famous demise of the dinosaurs at the Mesozoic-Cenozoic boundary, as well as an even larger extinction of marine life at the Paleozoic-Mesozoic boundary.  The beginning of the Paleozoic was defined as the occurrence of the first hard-shelled fossils

The oldest rocks on Earth come from Australia (actually, mineral grains contained in a younger quartzite), with ages as old as 4,400 mil.  The oldest significant exposures of very old rocks are found in Greenland, at 3,850 mil.

 Geologic Era Characteristic Life Cenozoic ('late life") Mammals Mesozoic ("middle life") Reptiles, dinosaurs Paleozoic ("early life") Invertebrate Marine life (clams, etc.), amphibians, first land plants Precambrian  (time before the Cambrian, the first geologic period with hard-shelled fossils) No hard-shelled fossils

 Big, Really Big!!   The Pacific Ocean covers almost one half of the Earth's surface. Approximately 90 million years from now, the Atlantic Ocean will be larger as the Pacific is shrinking approximately 2" per year. Water is the color blue, because it is a reflection of the sky.

The Oceans of our World:

Arctic Ocean:
The earth’s northern most cap. With an area of 12 million square kilometers (5 million square miles), the Arctic Ocean is the smallest ocean - more than five times smaller than the Indian and Atlantic oceans.

Atlantic Ocean:
Is a passive margin ocean with most of its geological activity centered along the Mid-Atlantic Ridge. Most of its coastal regions are low and geologically quiet. The Atlantic’s major marginal seas include the Mediterranean Sea, the North Sea, the Baltic Sea, Hudson Bay, the Gulf of Mexico, and the Caribbean Sea. The Atlantic covers an area of 82 million square kilometers (32 million square miles). It has an average depth of 3,600 meters (11,812 feet). Its greatest depth is in the Puerto Rico Trench at 8,605 meters (28,231 feet).

Indian Ocean:
The Indian Ocean covers an area of about 73 million square kilometers (about 28 million square miles) - about 20 percent of the total area covered by the world's oceans. The average depth of the Indian Ocean is 3,890 meters (12,762 feet). Its deepest point is the Java trench, at 7,725 m.

Pacific Ocean:
Is the world's largest geographic feature, the Pacific Ocean covers more than 166 million square kilometers (more than 64 million square miles)—about one-third of the earth's surface. The area of the Pacific is greater than that of all of the continents combined, and it makes up nearly half of the area covered by the earth's oceans.

Southern Ocean:
As of  2000, This body of water that lies between 60 degrees south latitude and the Antarctica coastline. The Southern Ocean has the unique distinction of being a large circumpolar body of water totally encircling the continent of Antarctica. This ring of water lies between 60 degrees south latitude and the coast of Antarctica, and encompasses 360 degrees of longitude. The Southern Ocean is now the fourth largest of the world's five oceans (after the Pacific Ocean, Atlantic Ocean, and Indian Ocean, but larger than the Arctic Ocean).

Our Largest Mountains:

The worlds "largest mountain" is in Hawaii Mauna Loa Volcano The worlds "tallest mountain" in Mt. Everest--this mountain is located on the Nepal and Tibet borders in China

- Mt. Everest is located in Nepal-China, in the Himalaya Range. It is 8,850 meters in elevation. (the tallest point on the earth’s surface.

-Chimorazo is located in Ecuador, in the Andes Range. It is 6.310 meters in elevation.

-Mauna Kea  located on the Hawaiian Islands chain in the United States. It is 4,205 meters in elevation. It
is the tallest mountain on Earth as measured from base to summit, with a total height of 10,203 meters. The base of Mauna Kea on the floor of the Pacific Ocean is 5,998 meters below mean sea level and its summit is 4,205 meters above mean sea level.

-Mauna Loa is located on the Hawaiian Islands chain in the United States. It is 4,169 meters in elevation. It also holds the record as the most voluminous mountain on Earth.

## 10 Highest Mountain Peaks:

 Rank Peak Range Region Elevation 1 Mount Everest Himalaya Nepal & Tibet 1 8,850 m 2 K2 Karakoram Kashmir 2 8,611 m 3 Kanchenjunga Himalaya India & Nepal 8,586 m 4 Lhotse I Himalaya Nepal & Tibet 1 8,516 m 5 Makalu I Himalaya Nepal & Tibet 1 8,463 m 6 Cho Oyu Himalaya Nepal & Tibet 1 8,201 m 7 Dhaulagiri Himalaya Nepal 8,167 m 8 Manaslu I Himalaya Nepal 8,163 m 9 Nanga Parbat Himalaya Kashmir 3 8,125 m 10 Annapurna I Himalaya Nepal 8,091 m

Six Highest Mountain Ranges:

 Rank Range Countries Highest peak Elevation 1 Himalaya Nepal China1 India Bhutan Pakistan Mount Everest 8,850 m 2 Karakoram Pakistan India China1 K2 8,611 m 3 Kunlun Shan China1 Kongkoerh 7,719 m 4 Hindu Kush Pakistan Afghanistan Tirich Mir 7,690 m 5 Hengduan Shan China1 Gongga Shan 7,556 m 6 Pamirs Tajikistan Afghanistan China1 Pik Ismail Samani 7,495 m

Note: The largest mountain range on the Planet Earth is 46,600 miles long, including its many branches, and almost all of it resides below the ocean's, some of the peaks rising 9,800 feet (3,000 km). Science was unaware of their existence until the1950's.

15 Largest Rivers:

-Nile: Africa. 6,690 km in length, Flows into the Mediterranean Sea.

-Amazon: South America. 6,290 km in length. Flows into the Atlantic Ocean

-Chang Jiang:  Eurasia/China. 5,797 km in length. Flows into the East China Sea.

-Huang He:  Eurasia/China. 4,667 in length. Flows into the Yellow Sea (Bo Hai).

-Yenisey:  Eurasia/Russia. 4,506 km in length. Flows into the Artic Ocean

-Irtysh: Eurasia/Russia. 4,438 km in length. Flows into the Ob' River.

-Congo:  Africa. 4,371 km in length. Flows into the Atlantic Ocean.

-Amur (Heilong): Eurasia. 4,352 km in length. Flows into the Tatar Strait.

-Lena: Eurasia/Russia. 4,268 km in length. Flows into the Artic Ocean

-Mackenzie: North America. 4,241 km in length. Flows into the Beaufort Sea.

-Niger: Africa. 4,184 km in length. Flows into the Gulf of Guinea.

-Mekong: Eurasia. 4,023 km in length. Flows into the South China Sea.

-Mississippi: North America. 3,779 km in length. Flows into the Gulf of Mexico.

-Missouri: North America. 3,726 km in length. Flows into the (Tributary of the) Mississippi.

-Volga: Eurasia/Russia. 3,687 km in length. Flows into the Caspian Sea.

The Largest Inland Seas & Lakes:

 -The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula. The Adriatic Sea is a part of the Mediterranean Sea. The western coast is Italian, while the eastern coast runs mostly along Croatia, but lesser parts belong to Slovenia, Bosnia and Herzegovina, Montenegro, and Albania. Major rivers joining the Adriatic are the Reno, Po, Adige, Brenta, Piave, Soča (Isonzo), Neretva. The Adriatic Sea is situated largely between the eastern coast of Italy and Croatia. The Adriatic extends northwest from 40° to 45° 45' N., with an extreme length of about 770 km. The northern part of the Adriati sea is very shallow, and between the southern promontories of Istria and Rimini the depth rarely exceeds 46 meters. Between Šibenik and Ortona a well-marked depression occurs, a considerable area of which exceeds 180 m in depth. From a point between Korčula and the north shore of the spur of Monte Gargano there is a ridge giving shallower water, and a broken chain of a few islets extends across the sea. The deepest part of the sea lies east of Monte Gargano, south of Dubrovnik, and west of Durrës where a large basin gives depths of 900 m and upwards, and a small area in the south of this basin falls below 1,460 m. The mean depth of the sea is estimated at 240 m.

 -Caspian Sea, Asia The Caspian Sea is the largest lake on Earth with a surface area of 371,000 square kilometers (143,244 mi) and a volume of 78,200 cubic kilometers (18,761 mi). It is a landlocked endorheic body of water and lies between Russia and Iran. It has a maximum depth of about 1025 meters (3,363 ft). It is called a sea because when the Romans first arrived there, they tasted the water and found it to be salty. It has a salinity of approximately 1.2%, about a third the salinity of most water from the ocean. 371,000 sq km/143,000 sq mi -Lake Superior, North America It is the largest of the five Great Lakes of North America. It is bounded to the north by Ontario, Canada and Minnesota, USA, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the world by surface area and is the world's third-largest freshwater lake by volume 82,100 sq km/31,700 sq mi -Lake Victoria, Africa Lake Victoria, the second largest freshwater lake in the world, is a shallow water lake formed as a result of a geographical system known as warping, stretches to the three East African countries of Uganda, Kenya and Tanzania. 69,490 sq km/26,830 sq mi -Lake Huron, North America Is the second-largest of the Great Lakes, with a surface area of 23,010 square miles (59,596 km) making it the third largest fresh water lake on earth (4th largest lake if the saline Caspian Sea is included). It contains a volume of 850 cubic miles (3,540 km³), and a shoreline length of 3,827 miles (6,157 km). The surface of lake Huron is 577 feet (176 m) above sea level 59,596 sq km/23,010 sq mi -Lake Michigan, North America It has a surface area of 22,400 square miles (58,016 km) making it the largest freshwater lake in the U.S., the largest lake entirely within one country by surface area (Lk. Baikal in Russia, is larger by water volume), and the fifth largest lake in the world. It is 307 miles (494 km) long by 118 miles (190 km) wide with a shoreline 1,640 miles (2,633 km) long. The lake's average depth is 279 feet (85 m), 57,800 sq km/22,300 sq mi -Lake Tanganyika, Africa It is estimated to be the second largest freshwater lake in the world by volume, and the second deepest, in both cases after Lake Baikal in Siberia. The lake is divided between four countries – Burundi, Democratic Republic of the Congo (DRC), Tanzania and Zambia 32,900 sq km/12,700 sq mi -Great Bear Lake, North America The third largest in North America, and the seventh largest in the world. The lake is situated on the Arctic Circle 186 m (610 ft) above sea level. The lake has a surface area of 31,153 km (12,028 mi) and a total volume of 2,236 km (536 mi). Its maximum depth is 446 m (1,463 ft) and its average depth 71.7 m (235 ft). The total shoreline is 2,719 km (1,690 mi) and the total catchment area of the lake is 114,717 km (44,293 mi). The lake empties through the Great Bear River (Sahtúdé) into the Mackenzie River. 31,153 sq km/12,028 sq mi -Lake Baikal, Asia/Russia (The Pearl of Siberia) Lake Baikal is the largest freshwater lake by volume of water. It is also the deepest lake in the world with a maximum depth of 1,637 m (5,371 ft). It is estimated to contain approximately one-fifth of all the earth's fresh surface water. The lake has an area of 31,500 sq km (12,200 sq mi) and about 1,963 km (about 1,220 mi) of shoreline, making it the third largest lake in Asia, as well as the continent’s largest freshwater lake in terms of surface area. The crescent-shaped lake is 636 km (395 mi) long and varies in width from about 14 to 80 km (about 9 to 50 mi). 31,500 sq km/12,200 sq mi -Great Slave Lake, North America The second largest lake, 10,980 sq mi (28,400 sq km), Northwest Territories, named for the Slave (Dogrib), a tribe of Native Americans. It is 300 mi (480 km) long and from 12 to 68 mi (19–109 km) wide and is the deepest lake (2,015 ft/614 m) of North America. The Hay and Slave rivers are its chief tributaries; it is drained by the Mackenzie River 28,400 sq km/10,980 sq mi

EARTHQUAKES

 RICHTER SCALE A measurement of an earthquake's intensity. Each one-point increase on the scale indicates ten times the amount of shaking and 33 times the amount of energy. Magnitude Description < 3.0 Very Minor Earthquake 3 - 3.9 Minor Earthquake 4 - 4.9 Light Earthquake 5 - 5.9 Moderate Earthquake 6 - 6.9 Strong Earthquake 7 - 7.9 Major Earthquake 8 and higher Great Earthquake

-
SEISMIC WAVES  (Seismology) -The energy created by the quake travels in waves from the epicenter, where they are the strongest. The waves shake buildings, structures and the earth vertically, causing them to move horizontally! The waves are the energy caused by the sudden breaking of rock within the earth or an explosion. There are several different kinds of seismic waves, and they all move in different ways. The two main types of waves are body waves and surface waves. Body waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes radiate seismic energy as both body and surface waves. Traveling through the interior of the earth, body waves arrive before the surface waves emitted by an earthquake. These waves are of a higher frequency than surface waves.

The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth. It pushes and pulls the rock it moves through just like sound waves push and pull the air. Have you ever heard a big clap of thunder and heard the windows rattle at the same time? The windows rattle because the sound waves were pushing and pulling on the window glass much like P waves push and pull on rock. Sometimes animals can hear the P waves of an earthquake. Dogs, for instance, commonly begin barking hysterically just before an earthquake 'hits' (or more specifically, before the surface waves arrive). Usually people can only feel the bump and rattle of these waves.

P waves are also known as compressional waves, because of the pushing and pulling they do. Subjected to a P wave, particles move in the same direction that the wave is moving in, which is the direction that the energy is traveling in, and is sometimes called the 'direction of wave propagation'.

The second type of body wave is the S wave or secondary wave, which is the second wave you feel in an earthquake. An S wave is slower than a P wave and can only move through solid rock, not through any liquid medium. It is this property of S waves that led seismologists to conclude that the Earth's outer core is a liquid. S waves move rock particles up and down, or side-to-side--perpindicular to the direction that the wave is traveling in (the direction of wave propagation).

Travelling only through the crust, surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost enitrely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes. Two other types, one being the Rayleigh wave, which rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves. The other the Love wave, it is the fastest surface wave and moves the ground from side-to-side. Confined to the surface of the crust, Love waves produce entirely horizontal motion.

-The Epicenter of an earthquake is the point on the Earth's surface directly above the focus. The location of an earthquake is commonly described by the geographic position of its epicenter and by its focal depth.
The focal depth of an earthquake is the depth from the Earth's surface to the region where an earthquake's energy originates (the focus). Earthquakes with focal depths from the surface to about 70 kilometers (43.5 miles) are classified as shallow. Earthquakes with focal depths from 70 to 300 kilometers (43.5 to 186 miles) are classified as intermediate. The focus of deep earthquakes may reach depths of more than 700 kilometers (435 miles). The focuses of most earthquakes are concentrated in the crust and upper mantle. The depth to the center of the Earth's core is about 6,370 kilometers (3,960 miles).

An Earthquake is the vibration, sometimes violent, of the Earth's surface that follows a release of energy in the Earth's crust. This energy can be generated by a sudden dislocation of segments of the crust, by a volcanic eruption, or event by manmade explosions. Most destructive quakes, however, are caused by dislocations of the crust
. There are about 20 plates along the surface of the earth that move continuously and slowly past each other. When the plates squeeze or stretch, huge rocks form at their edges and the rocks shift with great force, causing an earthquake. When the force is large enough, the crust is forced to break. When the break occurs, the stress is released as energy which moves through the Earth in the form of waves, which we feel and call an earthquake.

The crust may first bend and then, when the stress exceeds the strength of the rocks, break and "snap" to a new position. In the process of breaking, vibrations called "seismic waves" are generated. These waves travel outward from the source of the earthquake along the surface and through the Earth at varying speeds depending on the material through which they move. Some of the vibrations are of high enough frequency to be audible, while others are of very low frequency. These vibrations cause the entire planet to quiver or ring like a bell or tuning fork.

faults
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake - or may occur slowly, in the form of creep. Faults may range in length from a few millimeters to thousands of kilometers. Most faults produce repeated displacements over geologic time. Faults are divided into three main groups, depending on how they move.

-Normal or Reverse faults
During an earthquake, the rock on one side of the fault suddenly slips with respect to the other. The fault surface can be horizontal or vertical or some arbitrary angle in between. Earth scientists use the angle of the fault with respect to the surface (known as the dip) and the direction of slip along the fault to classify faults. Faults which move along the direction of the dip plane are dip-slip faults and described as either normal or reverse, depending on their motion, occurring in response to pulling or tension; the overlying block moves down the dip of the fault plane.

-Thrust (reverse) faults occur in response to squeezing or compression; the overlying block moves up the dip of the fault plane. A dip-slip fault in which the upper block, above the fault plane, moves up and over the lower block. This type of faulting is common in areas of compression, such as regions where one plate is being subducted under another. When the dip angle is shallow, a reverse fault is often described as a thrust fault.

-Strike-slip (lateral) faults occur in response to either type of stress; the blocks move horizontally past one another. Most faulting along spreading zones is normal, along subduction zones is thrust, and along transform faults is strike-slip.Faults which move horizontally are known as strike-slip faults and are classified as either right-lateral (A strike-slip fault on which the displacement of the far block is to the right when viewed from either side. The San Andreas Fault is an example of a right lateral fault.) or left-lateral (A strike-slip fault on which the displacement of the far block is to the left when viewed from either side).

Geologists have found that earthquakes tend to reoccur along faults, which reflect zones of weakness in the Earth's crust. Even if a fault zone has recently experienced an earthquake, however, there is no guarantee that all the stress has been relieved. Another earthquake could still occur. In *New Madrid (this earthquake measured 8.0, the strongest earthquake ever recorded in the contiguous United States). a great earthquake was followed by a large aftershock within 6 hours on December 6, 1811. Furthermore, relieving stress along one part of the fault may increase stress in another part; the New Madrid earthquakes in January and February 1812 may have resulted from this phenomenon.

Liquefaction occurs when the strength and stiffness of a soil is reduced by earthquake shaking or other rapid loading. *Liquefaction and related phenomena have been responsible for tremendous amounts of damage in historical earthquakes around the world. Liquefaction occurs in saturated soils, that is, soils in which the space between individual particles is completely filled with water. This water exerts a pressure on the soil particles that influences how tightly the particles themselves are pressed together. Prior to an earthquake, the water pressure is relatively low. However, earthquake shaking can cause the water pressure to increase to the point where the soil particles can readily move with respect to each other, which happens when loosely packed, water-logged sediments lose their strength in response to strong shaking, causes major damage during earthquakes.

Typical effects of liquefaction include:

Loss of bearing strength –the ground can liquefy and lose its ability to support structures.

Lateral spreading - the ground can slide down very gentle slopes or toward stream banks riding on a buried liquefied layer.

Sand boils - sand-laden water can be ejected from a buried liquefied layer and erupt at the surface to form sand volcanoes; the surrounding ground often fractures and settles.

Flow failures — earth moves down steep slope with large displacement and much internal disruption of material.

Ground oscillation — the surface layer, riding on a buried liquefied layer, is thrown back and forth by the shaking and can be severely deformed.

Flotation — light structures that are buried in the ground (like pipelines, sewers and nearly empty fuel tanks) can float to the surface when they are surrounded by liquefied soil.

Settlement — when liquefied ground re-consolidates following an earthquake, the ground surface may settle or subside as shaking decreases and the underlying liquefied soil

*Quicksand: (Quicksand forms when uprising water reduces the friction between sand particles, causing the sand to become "Quick")  It is actually solid ground that has been liquefied by a saturation of water. The "quick" refers to how easily the sand shifts when in this semiliquid state.

-Flowing underground water - The force of the upward water flow opposes the force of gravity, causing the granules of sand to be more buoyant.

-Earthquakes - The force of the shaking ground can increase the pressure of shallow groundwater, which liquefies sand and silt deposits. The liquefied surface loses strength, causing buildings or other objects on that surface to sink or fall over.

Quicksand is not a unique type of soil; it is usually just sand or another type of grainy soil. Quicksand is nothing more than a soupy mixture of sand and water. It can occur anywhere under the right conditions.

Quicksand is created when water saturates an area of loose sand and the ordinary sand is agitated. When the water trapped in the batch of sand can't escape, it creates liquefied soil that can no longer support weight. There are two ways in which sand can become agitated enough to create quicksand:

The vibration plus the water barrier reduces the friction between the sand particles and causes the sand to behave like a liquid. To understand quicksand, you have to understand the process of liquefaction. When soil liquefies, as with quicksand, it loses strength and behaves like a viscous liquid rather than a solid. Liquefaction can cause buildings to sink significantly during earthquakes.

While quicksand can occur in almost any location where water is present, there are certain locations where it's more prevalent. Places where quicksand is most likely to occur include: On beaches, Lakes shorelines, Marshes, Riverbanks and near springs.

If you step into quicksand, you will not be sucked down. However, your movements will ca­use you to dig yourself deeper into it. When you do make contact with quicksand, the more you struggle in it, the faster you sink. If you relax, your body will float in it because your body is less dense. Further, quicksand is typically inches deep and occasionally a few feet ( but not always).

Quicksand has a density of about 125 pounds per cubic foot, which means you can float more easily on quicksand than on water. The key is to not panic. Most people who drown in quicksand are usually those who panic and begin flailing their arms and legs.

It may be possible to drown in quicksand if you were to fall in over your head and couldn't get your head back above the surface, although it's rare for quicksand to be that deep. Most likely, if you fall in, you will float to the surface. However, the sand-to-water ratio of quicksand can vary, causing some quicksand to be less buoyant. When you try pulling your leg out of quicksand or mud for that matter, you are working against a vacuum left behind by the movement,

The best thing to do is to make slow movements and bring yourself to the surface, then just lie on your back,  paddle slowly with your arms stretched out wide,  and if possible heading  for the edge.

Landslides, some triggered by earthquakes often cause more destruction than the earthquakes themselves. A common theme is the role of topographic amplification in landslide triggering (this is the way in which earthquake waves interact with slopes to cause higher levels of ground shaking, which in turn triggers slope failures).

Expansion of urban and recreational developments into hillside areas leads to more people that are threatened by landslides each year. Landslides commonly occur in connection with other major natural disasters such as earthquakes, volcanoes, wildfires, and floods.

The hazard from landslides can be reduced by avoiding construction on steep slopes and existing landslides, or by stabilizing the slopes. Stability increases when ground water is prevented from rising in the landslide mass by;covering the landslide with an impermeable membrane, directing surface water away from the landslide, draining ground water away from the landslide, and minimizing surface irrigation. Slope stability is also increased when a retaining structure and/or the weight of a soil/rock berm are placed at the toe of the landslide or when mass is removed from the top of the slope.

Landslide Warnings:

• Springs, seeps, or saturated ground in areas that have not typically been wet before.
• New cracks or unusual bulges in the ground, street pavements or sidewalks.
• Soil moving away from foundations.
• Ancillary structures such as decks and patios tilting and/or moving relative to the main house.
• Tilting or cracking of concrete floors and foundations.
• Broken water lines and other underground utilities.
• Leaning telephone poles, trees, retaining walls or fences.
• Offset fence lines.
• Sunken or down-dropped road beds.
• Rapid increase in creek water levels, possibly accompanied by increased turbidity (soil content).
• Sudden decrease in creek water levels though rain is still falling or just recently stopped.
• Sticking doors and windows, and visible open spaces indicating jambs and frames out of plumb.
• A faint rumbling sound that increases in volume is noticeable as the landslide nears.
• Unusual sounds, such as trees cracking or boulders knocking together, might indicate moving debris.

*The New Madrid Seismic Zone, also known as the "Reelfoot Rift" or "the New Madrid Fault Line", is a major seismic zone in the Southern and Midwestern United States.

As a result of the quakes, large areas sank into the earth, new lakes were formed (notably Reelfoot Lake, Tennessee), and the Mississippi River changed its course, creating numerous geographic exclaves, including Kentucky Bend, along the state boundaries which are defined by the river.

 El Niño, La Niña and ENSO El Niño and La Niña are extreme phases of a naturally occurring climate cycle referred to as El Niño/Southern Oscillation. These terms refer to large-scale changes in sea-surface temperature across the eastern tropical Pacific The terms ENSO and ENSO cycle are used to describe the full range of variability observed in the Southern Oscillation Index, including both El Niño and La Niña events. Unusual weather conditions occur around the globe as jet streams, storm tracks and monsoons are shifted. Such disarray is caused by a warm current of water that appears in the eastern Pacific Ocean called El Niño. Unfortunately not all El Nino's are the same nor does the atmosphere always react in the same way from one El Nino to another. To date Scientists do not really understand how El Nino actually forms. Unfortunately, the abundant fish populations found off the west coast of Peru South America become the sight of dead fish littering the water and beaches. El Niño  (Southern Oscillation/ENSO) is  a large scale weakening of the trade winds and warming of the surface layers in the eastern and central equatorial Pacific Ocean. El Niño has irregular patterns although the average is about once every 3-4 years. They typically last 12-18 months, and are accompanied by swings in the Southern Oscillation due to tropical sea level pressure between the eastern and western hemispheres. During El Niño, unusually high atmospheric sea level pressures develop in the western tropical Pacific and Indian Ocean regions, and unusually low sea level pressures develop in the southeastern tropical Pacific. In the continental US, during El Niño years, temperatures in the winter are warmer than normal in the North Central States, and cooler than normal in the Southeast and the Southwest. During a La Niña year, winter temperatures are warmer than normal in the Southeast and cooler than normal in the Northwest. At the high latitudes, El Niño and La Niña are among a number of factors that influence climate. However, the impacts of El Niño and La Niña at these latitudes are most clearly seen in wintertime The Southern Oscillation Index is the difference in surface pressure between Tahiti, French Polynesia and Darwin, Australia is a measure of the strength of the trade winds, which have a component of flow from regions of high to low pressure. High SOI (large pressure difference) is associated with stronger than normal trade winds and La Niña conditions, and low SOI (smaller pressure difference) is associated with weaker than normal trade winds and El Niño conditions.  El Niño denotes a warm southward flowing ocean current that occurs every year around late December off the west coast of Peru and Ecuador. The term was later restricted to unusually strong warmings that disrupted local fish and bird populations every few years. However, as a result of the frequent association of South American coastal temperature anomalies with interannual basin scale equatorial warm events, El Niño has also become synonymous with larger scale, climatically significant, warm events. There is not, however, unanimity in the use of the term El Niño. La Niña, is defined as colder than normal sea-surface temperatures in the central and eastern tropical Pacific ocean that impact global weather patterns. La Niña conditions recur every few years and can persist for as long as two years. La Niña is preceded by a buildup of cooler-than-normal subsurface waters in the tropical Pacific. Eastward-moving atmospheric and oceanic waves help bring the cold water to the surface through a complex series of events still being studied. In time, the easterly trade winds strengthen, cold upwelling off Peru and Ecuador intensifies, sea-surface temperatures along the equator can fall as much as 7 degrees F below normal. La Niña conditions typically last approximately 9-12 months, and occasionally episodes may continue for a few years.

GALAXIES

Galaxies are large systems of stars and interstellar matter, typically containing several million to some trillion stars. Some with masses between several million and several trillion times that of our Sun, typically separated by millions of light years in distance. The galaxies represent a variety: Spiral, lenticular, elliptical and irregular. Besides simple stars, they typically contain various types of star clusters and nebulae.

 Retreating Galaxies of the ever expanding Universe Ho=V/D Ho=constant/ V Recessional = velocity and D = the distance away from Earth   The Universe is approximately 12.5 Billion years old, the Earth 4.5 Billion years old.

 Satellite Galaxies of The Milky Way Light Years from Earth Canis Major Dwarf Galaxy 25,000 Virgo Stellar Stream 30,000 Sagittarius Dwarf Elliptical Galaxy 81,000 Large Magellanic Cloud 168,000 Boötes Dwarf Galaxy 197,000 Small Magellanic Cloud 200,000 Ursa Minor Dwarf Galaxy 240,000 Sculptor Dwarf Galaxy 254,000 Draco Dwarf Galaxy 280,000 Sextans Dwarf Galaxy 320,000 Ursa Major Dwarf 330,000 Carina Dwarf Galaxy 360,000 Fornax Dwarf Galaxy 460,000

The next nearest Galaxy is almost double the light years from that of the Fornax Dwarf Galaxy.

Andromeda:

This is the nearest major galaxy to our own Milky Way. It is about 900 kiloparsecs or 3 million light years away. It is similar to our own galaxy in structure with spiral arms, a bulging central disc and is about 30 kiloparsecs across.

Magellanic clouds:

Two small irregular galaxies called the "Magellanic Clouds" are relatively near the Milky Way. The Large Magellanic Cloud is at about 160,000 light years and the Small Magellanic Cloud is at about 200,000 light years from us.

Triangulum Galaxy:

This is a *spiral Galaxy, also known as Messier 33 or NGC 598. This galaxy is approximately 3 million light-years away from earth in the constellation Triangulum. (It is not the Pinwheel Galaxy, which is Messier 101) Messier 33 is the most distant object seen by the naked eye.

Spiral and Elliptical Galaxies

### Ellipticals

Elliptical galaxies were denoted by the letter E and a number describing the galaxy's apparent shape - 0 for a completely round form, 5 for one twice as long as wide, and 7 for the apparently flattest genuine ellipticals. It is not known, solely from an image, the actual true shape of such a galaxy; the same galaxy might have quite different degrees of flattening if viewed from different directions. Elliptical galaxies are, in general, characterized by old stellar populations and very little of the gas and dust needed to form new stars. They have a uniform luminosity and are similar to the bulge in a spiral galaxy, but with no disk. The stars are old and there is no gas present. These are small galaxies with no bulge and an ill-defined shape. "The Magellenic clouds are examples".

### Lenticulars

They possess both a bulge and a disk, but lack spiral arms. There is little or no gas and so all the stars are old. They appear to be an intermediate.

### *Spirals

Fall into several classes depending on their shape and the relative size of the bulge. Spiral galaxies are characterized by the presence of gas in the disk which means star formation remains active at the present time, hence the younger population of stars. Spirals are divided into ordinary and barred spirals; in barred systems the spiral arms arise from a straight ``bar" passing through the center, while ordinary spirals have a more S-shaped inner configuration. Ordinary spiral are denoted S and barred systems SB. Both usually contain a central bulge, often sharing many properties with elliptical galaxies, surrounded by a thin rotating disk containing whatever spiral structure there may be. Spirals are subdivided into a sequence jointly defined by the winding and prominence of the spiral arms, and the relative importance of the central bulge. Spirals are usually found in the low density galactic field where their delicate shape can avoid disruption by tidal forces from neighboring galaxies.

 Q.T. Did you know that parts of the Rocky Mountains are still growing higher.

GRAVITY

The orbit of the Moon about the Earth could be a consequence of the gravitational force, because the acceleration due to gravity could change the velocity of the Moon in just such a way that it followed an orbit around the earth.

This can be illustrated with the thought experiment shown in the following figure. Suppose we fire a cannon horizontally from a high mountain; the projectile will eventually fall to earth, as indicated by the shortest trajectory in the figure, because of the gravitational force directed toward the center of the Earth and the associated acceleration. (Remember that an acceleration is a change in velocity and that velocity is a vector, so it has both a magnitude and a direction. Thus, an acceleration occurs if either or both the magnitude and the direction of the velocity change.)

But as we increase the muzzle velocity for our imaginary cannon, the projectile will travel further and further before returning to earth. Finally, Newton reasoned that if the cannon projected the cannon ball with exactly the right velocity, the projectile would travel completely around the Earth, always falling in the gravitational field but never reaching the Earth, which is curving away at the same rate that the projectile falls. That is, the cannon ball would have been put into orbit around the Earth. Newton concluded that the orbit of the Moon was of exactly the same nature: the Moon continuously "fell" in its path around the Earth because of the acceleration due to gravity, thus producing its orbit.

By such reasoning, Newton came to the conclusion that any two objects in the Universe exert gravitational attraction on each other, with the force having a universal form:

The constant of proportionality G is known as the universal gravitational constant. It is termed a "universal constant" because it is thought to be the same at all places and all times, and thus universally characterizes the intrinsic strength of the gravitational force.

## The Center of Mass for a Binary System

If you think about it a moment, it may seem a little strange that in Kepler's Laws the Sun is fixed at a point in space and the planet revolves around it. Why is the Sun privileged? Kepler had rather mystical ideas about the Sun, endowing it with almost god-like qualities that justified its special place. However Newton, largely as a corollary of his 3rd Law, demonstrated that the situation actually was more symmetrical than Kepler imagined and that the Sun does not occupy a privileged postion; in the process he modified Kepler's 3rd Law. where R is the total separation between the centers of the two objects. The center of mass is familiar to anyone who has ever played on a see-saw. The fulcrum point at which the see-saw will exactly balance two people sitting on either end is the center of mass for the two persons sitting on the see-saw.

## Newton's Modification of Kepler's Third Law

Because for every action there is an equal and opposite reaction, Newton realized that in the planet-Sun system the planet does not orbit around a stationary Sun. Instead, Newton proposed that both the planet and the Sun orbited around the common center of mass for the planet-Sun system. He then modified Kepler's 3rd Law to read,

where P is the planetary orbital period and the other quantities have the meanings described above, with the Sun as one mass and the planet as the other mass. (As in the earlier discussion of Kepler's 3rd Law, this form of the equation assumes that masses are measured in solar masses, times in Earth years, and distances in astronomical units.) Notice the symmetry of this equation: since the masses are added on the left side and the distances are added on the right side, it doesn't matter whether the Sun is labeled with 1 and the planet with 2, or vice-versa. One obtains the same result in either case.

Now notice what happens in Newton's new equation if one of the masses (either 1 or 2; remember the symmetry) is very large compared with the other. In particular, suppose the Sun is labeled as mass 1, and its mass is much larger than the mass for any of the planets. Then the sum of the two masses is always approximately equal to the mass of the Sun, and if we take ratios of Kepler's 3rd Law for two different planets the masses cancel from the ratio and we are left with the original form of Kepler's 3rd Law:

Thus Kepler's 3rd Law is approximately valid because the Sun is much more massive than any of the planets and therefore Newton's correction is small. The data Kepler had access to were not good enough to show this small effect. However, detailed observations made after Kepler show that Newton's modified form of Kepler's 3rd Law is in better accord with the data than Kepler's original form.

## Two Limiting Cases

We can gain further insight by considering the position of the center of mass in two limits. First consider the example just addressed, where one mass is much larger than the other. Then, we see that the center of mass for the system essentially concides with the center of the massive object:

This is the situation in the Solar System: the Sun is so massive compared with any of the planets that the center of mass for a Sun-planet pair is always very near the center of the Sun. Thus, for all practical purposes the Sun IS almost (but not quite) motionless at the center of mass for the system, as Kepler originally thought.

However, now consider the other limiting case where the two masses are equal to each other. Then it is easy to see that the center of mass lies equidistant from the two masses and if they are gravitationally bound to each other, each mass orbits the common center of mass for the system lying midway between them:

This situation occurs commonly with binary stars (two stars bound gravitationally to each other so that they revolve around their common center of mass). In many binary star systems the masses of the two stars are similar and Newton's correction to Kepler's 3rd Law is very large.

These limiting cases for the location of the center of mass are perhaps familiar from our afore-mentioned playground experience. If persons of equal weight are on a see-saw, the fulcrum must be placed in the middle to balance, but if one person weighs much more than the other person, the fulcrum must be placed close to the heavier person to achieve balance.

## Weight and the Gravitational Force

We have seen that in the Universal Law of Gravitation the crucial quantity is mass. In popular language mass and weight are often used to mean the same thing; in reality they are related but quite different things. What we commonly call weight is really just the gravitational force exerted on an object of a certain mass. We can illustrate by choosing the Earth as one of the two masses in the previous illustration of the Law of Gravitation:

Thus, the weight of an object of mass m at the surface of the Earth is obtained by multiplying the mass m by the acceleration due to gravity, g, at the surface of the Earth. The acceleration due to gravity is approximately the product of the universal gravitational constant G and the mass of the Earth M, divided by the radius of the Earth, r, squared. (We assume the Earth to be spherical and neglect the radius of the object relative to the radius of the Earth in this discussion.) The measured gravitational acceleration at the Earth's surface is found to be about 980 cm/second/second.

## Mass and Weight

Mass is a measure of how much material is in an object, but weight is a measure of the gravitational force exerted on that material in a gravitational field; thus, mass and weight are proportional to each other, with the acceleration due to gravity as the proportionality constant. It follows that mass is constant for an object (actually this is not quite true, but we will save that surprise for our later discussion of the Relativity Theory), but weight depends on the location of the object. For example, if we transported the preceding object of mass m to the surface of the Moon, the gravitational acceleration would change because the radius and mass of the Moon both differ from those of the Earth. Thus, our object has mass m both on the surface of the Earth and on the surface of the Moon, but it will weigh much less on the surface of the Moon because the gravitational acceleration there is a factor of 6 less than at the surface of the Earth.

 HURRICANES/TYPHOONS/TROPICAL CYCLONES Hurricanes draw their energy from the warm surface water of the tropics, which explains why hurricanes dissipate rapidly once they move over cold water or large land masses The path of a hurricane greatly depends upon the wind belt in which it is located. A hurricane originating in the eastern tropical Atlantic, for example, is driven westward by easterly trade winds in the tropics. Eventually, these storms turn northwestward around the subtropical high and migrate into higher latitudes. As a result, the Gulf of Mexico and East Coast of the United States are at risk to experience one or more hurricanes each year. Hurricanes are also rated according to their wind speed. The scale ranges from categories 1 to 5, with 5 being the most devastating. The global wind pattern is also known as the "general circulation" and the surface winds of each hemisphere are divided into three wind belts: -Polar Easterlies = from 60-90 degrees latitude. -Prevailing  Westerlies = from 30-60 degrees latitude. -Tropical (known as Trade winds) Easterlies = from 0-30 degrees latitudes. A HURRICANE WATCH issued for your part of the coast indicates the possibility that you could experience hurricane conditions within 36 hours. This watch should trigger your family's disaster plan, and protective measures should be initiated, especially those actions that require extra time such as securing a boat, leaving a barrier island, etc. A HURRICANE WARNING issued for your part of the coast indicates that sustained winds of at least 74 mph are expected within 24 hours or less. Once this warning has been issued, your family should be in the process of completing protective actions and deciding the safest location to be during the storm. Hurricanes are a severe tropical storm that forms in the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160E. Hurricanes need warm tropical oceans, moisture and light winds above them. If the right conditions last long enough, a hurricane can produce violent winds, incredible waves, torrential rains and floods. In other regions of the world, these types of storms have different names. -Hurricane (The North Atlantic Ocean, The Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160 E) -Typhoon (the Northwest Pacific Ocean west of the dateline) -Severe tropical cyclone (the Southwest Pacific Ocean west of 160E or Southeast Indian Ocean east of 90E) -Severe cyclonic storm (the North Indian Ocean) -Tropical cyclone (the Southwest Indian Ocean) Severity: "Super-typhoon" is a term utilized by the U.S. Joint Typhoon Warning Center for typhoons that reach maximum sustained 1-minute surface winds of at least 65 m/s (130 kt, 150 mph). This is the equivalent of a strong Saffir-Simpson category 4 or category 5 hurricane in the Atlantic basin or a category 5 severe tropical cyclone in the Australian basin. "Major hurricane/Intense hurricane" is a term utilized by the National Hurricane Center for hurricanes that reach maximum sustained 1-minute surface winds of at least 50 m/s (96 kt, 111 mph). This is the equivalent of category 3, 4 and 5 on the Saffir-Simpson scale. Hurricanes rotate in a counterclockwise direction around an "eye." A tropical storm becomes a hurricane when winds reach 74 mph. There are on average six Atlantic hurricanes each year; over a three-year period, approximately five hurricanes strike the United States coastline from Texas to Maine. The Atlantic hurricane season begins June 1 and ends November 30. The East Pacific hurricane season runs from May 15 through November 30, with peak activity occurring during July through September. When hurricanes move onto land, the heavy rain, strong winds and heavy waves can damage buildings, trees and cars. The heavy waves are called a storm surge. Storm surge is very dangerous and a major reason why you MUST stay away from the ocean during a hurricane.

LAHAR
Lahar is an Indonesian term that describes a hot or cold mixture of water and rock fragments flowing down the slopes of a volcano and (or) river valleys.

#### Scientists often use more specific terms than lahar when referring to moving masses of water and rock debris

Debris Flows:

Dense flows that consist of a relatively high percentage of coarse rock particles are debris flows. The size of sediment transported by debris flows ranges in size from clay and silt (less than 0.06 mm) to boulders as large as 10 m in diameter. A typical debris flow consists of about 2 parts sediment for every one part water. Thus, debris flows may consist of more than 80 percent sediment by weight!

#### Mudflow:

A debris flow composed of relatively small rock particles, dominantly sand and silt-sized particles (less than 2 mm in diameter), is often called a mudflow. Even though mudflows can transport large boulders and can have sediment concentrations as great as debris flows, their sediment composition typically consists of at least 50 percent sand, silt, and clay-size particles ("mud" refers to silt- and clay-size particles). Mudflow is probably the most familiar and commonly used term by nonscientists to describe dense mixtures of flowing sediment and water.

#### Hyperconcentrated Streamflow:

A flow containing between 40 and 80 percent sediment by weight is often referred to as hyperconcentrated streamflow. Debris flows and mudflows represent the most dense and concentrated mixtures of flowing sediment and water; they commonly are composed of more than 80 percent sediment by weight. Normal streamflow, which may contain as much as 40 percent sediment by weight, is the least dense and concentrated mixture of flowing sediment and water. Hyperconcentrated flows are finer grained than debris flows and mudflows, usually consisting of predominantly of sand-size particles. As a debris flow or mudflow moves down a river valley, they will eventually become more dilute by mixing with water in the river and by losing some of the sediment. When the percentage of sediment by weight drops below 80 percent, the flow transforms into hyperconcentrate streamflow.

#### Cohesive Lahars:

Debris flows or mudflows that contain more than 3 to 5 percent of clay-size sediment are sometimes referred to as cohesive lahars. Scientists may sometimes conclude that a relatively high concentration of clay in these flows indicates it began as a large landslide from the flank of a volcano. The interior parts of many volcanoes have been hydrothermally altered and consist of many clay particles.

#### Non-cohesive Lahars"

Debris flows or mudflows that contain less than 3 to 5 percent of clay-size sediment are sometimes referred to as non-cohesive lahars. Such a relatively low proportion of clay in this volcanic debris is considered by some scientists to be evidence that the lahar did not originate as a volcanic landslide, but rather in another way. For example, by the mixing of water melted from snow and ice with volcanic debris.

When moving, a lahar looks like a mass of wet concrete that carries rock debris ranging in size from clay to boulders more than 10 m in diameter. Lahars vary in size and speed. Small lahars less than a few meters wide and several centimeters deep may flow a few meters per second. Large lahars hundreds of meters wide and tens of meters deep can flow several tens of meters per second--much too fast for people to outrun.

As a lahar rushes downstream from a volcano, its size, speed, and the amount of water and rock debris it carries constantly change. The beginning surge of water and rock debris often erodes rocks and vegetation from the side of a volcano and along the river valley it enters. This initial flow can also incorporate water from melting snow and ice (if present) and the river it overruns. By eroding rock debris and incorporating additional water, lahars can easily grow to more than 10 times their initial size. But as a lahar moves farther away from a volcano, it will eventually begin to lose its heavy load of sediment and decrease in size.

Eruptions may trigger one or more lahars directly by quickly melting snow and ice on a volcano or ejecting water from a crater lake. More often, lahars are formed by intense rainfall during or after an eruption--rainwater can easily erode loose volcanic rock and soil on hillsides and in river valleys. Some of the largest lahars begin as landslides of saturated and hydrothermally altered rock on the flank of a volcano or adjacent hillslopes. Landslides are triggered by eruptions, earthquakes, precipitation, or the unceasing pull of gravity on the volcano.
Lahars almost always occur on or near stratovolcanoes because these volcanoes tend to erupt explosively and their tall, steep cones are either snow covered, topped with a crater lake, constructed of weakly consolidated rock debris that is easily eroded, or internally weakened by hot hyrothermal fluids. Lahars are also common from the snow- and ice-covered shield volcanoes in Iceland where eruptions of fluid basalt lava frequently occur beneath huge glacier

Lahars racing down river valleys and spreading across flood plains tens of kilometers downstream from a volcano often cause serious economic and environmental damage. The direct impact of a lahar's turbulent flow front or from the boulders and logs carried by the lahar can easily crush, abrade, or shear off at ground level just about anything in the path of a lahar. Even if not crushed or carried away by the force of a lahar, buildings and valuable land may become partially or completely buried by one or more cement-like layers of rock debris. By destroying bridges and key roads, lahars can also trap people in areas vulnerable to other hazardous volcanic activity, especially if the lahars leave deposits that are too deep, too soft, or too hot to cross.

After a volcanic eruption, the erosion of new loose volcanic deposits in the headwaters of rivers can lead to severe flooding and extremely high rates of sedimentation in areas far downstream from a volcano. Over a period of weeks to years, post-eruption lahars and high-sediment discharges triggered by intense rainfall frequently deposit rock debris that can bury entire towns and valuable agricultural land. Such lahar deposits may also block tributary stream valleys. As the area behind the blockage fills with water, areas upstream become inundated. If the lake is large enough and it eventually overtops or breaks through the lahar blockage, a sudden flood or a lahar may bury even more communities and valuable property downstream from the tributary.

 QT.  billionth of a second  =  Nanosecond          trillionth-of-a-second  = Picosecond

 The nearest Galaxy (The planet Earth resides within the Milky Way galaxy) is Proxima Centauri, 25 Trillion miles away.

 -Conversion of Mass- A rusty object doesn't lose weight, but gains weight. The rusting object attracts particles in the air, this matter can be transformed, but not eliminated.

MOTION

## Motion is relative

All motion is relative to the observer or to some fixed object. When you see a car drive by, it is moving with respect to you. If you are in a car that is going at the same speed, the other car will not by moving with respect to you. But both cars are moving with respect to the ground. Using the Sun as an example, it is not moving across the sky (although it is traveling through the Milky Way galaxy), the Planet Earth is. We consider motion with respect to the ground or the Earth. Within the Universe there is no real fixed point. The basis for Einstein's Theory of Relativity is that all motion is relative to what you define as a fixed point.

### First Law of Motion: Law of Inertia

Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

Second Law of Motion:

The relationship between an object's mass m, its acceleration a, and the applied force f is F=ma.
Acceleration and force are vectors (as indicated by their symbols being displayed in slant font); in
this law the direction of the force vector is the same as direction of the acceleration vector.

This is the most powerful of Newton's three Laws, because it allows quantitative calculations of dynamics: how do velocities change when forces are applied. Notice the fundamental difference between Newton's 2nd Law and the dynamics of Aristotle: according to Newton, a force causes only a change in velocity (an acceleration); it does not maintain the velocity as Aristotle held.

This is sometimes summarized by saying that under Newton, F = ma, but under Aristotle F = mv, where v is the velocity. Thus, according to Aristotle there is only a velocity if there is a force, but according to Newton an object with a certain velocity maintains that velocity unless a force acts on it to cause an acceleration.

Aristotle's view seems to be more in accord with common sense, but that is because of a failure to appreciate the role played by frictional forces. Once account is taken of all forces acting in a given situation it is the dynamics of Galileo and Newton, not of Aristotle, that are found to be in accord with the observations.

Third Law of Motion:

For Every action there is an equal and opposite reaction.

### -Measurement

In order to determine how fast an object is going, you measure the time it takes to cover a given distance, using the equation

d = vt

where:

• d is the distance
• v is the speed or velocity
• t is the time covered
• vt is v times t

From this equation, you can get the equation for velocity as v = d/t. Velocity (v) or speed equals the distance (d) traveled divided by the time (t) it takes to go that distance.

We distinguish between speed and velocity because if you add the speeds of objects, their directions are important. For example, the velocity of an airplane with respect to the ground would vary according to the direction of the wind.

-Acceleration is the increase of velocity over a period of time. Deceleration is the decrease of velocity. When you start running, you accelerate (increase your velocity) until you reach a constant speed.

Mathematically, acceleration is the change in velocity divided by the time for the change

a = (v2 − v1)/(t2 − t1)

where:

• v2 − v1 is the end velocity minus the beginning velocity
• t2 − t1 is the measured time period between the two velocities

Often this is written as a = Δv/Δt, where Δ is the Greek letter delta and stands for difference.

NERVOUS SYSTEM

Multicellular animals must continually monitor and maintain a constant internal environment as well as monitor and respond to an external environment. In most, these two functions are coordinated by two integrated and coordinated organ systems: the nervous system and the endocrine system.

Three basic functions are performed by nervous systems:

1. Receive sensory input from internal and external environments
2. Integrate the input
3. Respond to stimuli

#### Sensory Input

Receptors are parts of the nervous system that sense changes in the internal or external environments. Sensory input can be in many forms, including pressure, taste, sound, light, blood pH, or hormone levels that are converted to a signal and sent to the brain or spinal cord.

#### Integration and Output

In the sensory centers of the brain or in the spinal cord, the barrage of input is integrated and a response is generated. The response, a motor output, is a signal transmitted to organs than can convert the signal into some form of action, such as movement, changes in heart rate, release of hormones, etc.

#### Endocrine Systems

Some animals have a second control system, the endocrine system. The nervous system coordinates rapid responses to external stimuli. The endocrine system controls slower, longer lasting responses to internal stimuli. Activity of both systems is integrated.

#### Divisions of the Nervous System:

The nervous system monitors and controls almost every organ system through a series of positive and negative feedback loops.The Central Nervous System (CNS) includes the brain and spinal cord. The Peripheral Nervous System (PNS) connects the CNS to other parts of the body, and is composed of nerves (bundles of neurons).

Not all animals have highly specialized nervous systems. Those with simple systems tend to be either small and very mobile or large and immobile. Large, mobile animals have highly developed nervous systems: the evolution of nervous systems must have been an important adaptation in the evolution of body size and mobility.

Coelenterates, cnidarians, and echinoderms have their neurons organized into a nerve net. These creatures have radial symmetry and lack a head. Although lacking a brain or either nervous system (CNS or PNS) nerve nets are capable of some complex behavior.

Bilaterally symmetrical animals have a body plan that includes a defined head and a tail region. Development of bilateral symmetry is associated with cephalization, the development of a head with the accumulation of sensory organs at the front end of the organism. Flatworms have neurons associated into clusters known as ganglia, which in turn form a small brain. Vertebrates have a spinal cord in addition to a more developed brain.

Chordates have a dorsal rather than ventral nervous system. Several evolutionary trends occur in chordates: spinal cord, continuation of cephalization in the form of larger and more complex brains, and development of a more elaborate nervous system. The vertebrate nervous system is divided into a number of parts. The central nervous system includes the brain and spinal cord. The peripheral nervous system consists of all body nerves. Motor neuron pathways are of two types: somatic (skeletal) and autonomic (smooth muscle, cardiac muscle, and glands). The autonomic system is subdivided into the sympathetic and parasympathetic systems.

### Neurons

Nervous tissue is composed of two main cell types: neurons and glial cells. Neurons transmit nerve messages. Glial cells are in direct contact with neurons and often surround them.

The neuron is the functional unit of the nervous system. Humans have about 100 billion neurons in their brain alone! While variable in size and shape, all neurons have three parts. Dendrites receive information from another cell and transmit the message to the cell body. The cell body contains the nucleus, mitochondria and other organelles typical of eukaryotic cells. The axon conducts messages away from the cell body.

Three types of neurons occur. Sensory neurons typically have a long dendrite and short axon, and carry messages from sensory receptors to the central nervous system. Motor neurons have a long axon and short dendrites and transmit messages from the central nervous system to the muscles (or to glands). Interneurons are found only in the central nervous system where they connect neuron to neuron.

Some axons are wrapped in a myelin sheath formed from the plasma membranes of specialized glial cells known as Schwann cells. Schwann cells serve as supportive, nutritive, and service facilities for neurons. The gap between Schwann cells is known as the node of Ranvier, and serves as points along the neuron for generating a signal. Signals jumping from node to node travel hundreds of times faster than signals traveling along the surface of the axon. This allows your brain to communicate with your toes in a few thousandths of a second.

### The Nerve Message

The plasma membrane of neurons, like all other cells, has an unequal distribution of ions and electrical charges between the two sides of the membrane. The outside of the membrane has a positive charge, inside has a negative charge. This charge difference is a resting potential and is measured in millivolts. Passage of ions across the cell membrane passes the electrical charge along the cell. The voltage potential is -65mV (millivolts) of a cell at rest (resting potential). Resting potential results from differences between sodium and potassium positively charged ions and negatively charged ions in the cytoplasm. Sodium ions are more concentrated outside the membrane, while potassium ions are more concentrated inside the membrane. This imbalance is maintained by the active transport of ions to reset the membrane known as the sodium potassium pump. The sodium-potassium pump maintains this unequal concentration by actively transporting ions against their concentration gradients.

Changed polarity of the membrane, the action potential, results in propagation of the nerve impulse along the membrane. An action potential is a temporary reversal of the electrical potential along the membrane for a few milliseconds. Sodium gates and potassium gates open in the membrane to allow their respective ions to cross. Sodium and potassium ions reverse positions by passing through membrane protein channel gates that can be opened or closed to control ion passage. Sodium crosses first. At the height of the membrane potential reversal, potassium channels open to allow potassium ions to pass to the outside of the membrane. Potassium crosses second, resulting in changed ionic distributions, which must be reset by the continuously running sodium-potassium pump. Eventually enough potassium ions pass to the outside to restore the membrane charges to those of the original resting potential. The cell begins then to pump the ions back to their original sides of the membrane.

The action potential begins at one spot on the membrane, but spreads to adjacent areas of the membrane, propagating the message along the length of the cell membrane. After passage of the action potential, there is a brief period, the refractory period, during which the membrane cannot be stimulated. This prevents the message from being transmitted backward along the membrane.

#### Steps in an Action Potential

1. At rest the outside of the membrane is more positive than the inside.
2. Sodium moves inside the cell causing an action potential, the influx of positive sodium ions makes the inside of the membrane more positive than the outside.
3. Potassium ions flow out of the cell, restoring the resting potential net charges.
4. Sodium ions are pumped out of the cell and potassium ions are pumped into the cell, restoring the original distribution of ions.

#### Synapses

The junction between a nerve cell and another cell is called a synapse. Messages travel within the neuron as an electrical action potential. The space between two cells is known as the synaptic cleft. To cross the synaptic cleft requires the actions of neurotransmitters. Neurotransmitters are stored in small synaptic vessicles clustered at the tip of the axon.

Neurotransmitters tend to be small molecules, some are even hormones. The time for neurotransmitter action is between 0,5 and 1 millisecond. Neurotransmitters are either destroyed by specific enzymes in the synaptic cleft, diffuse out of the cleft, or are reabsorbed by the cell. More than 30 organic molecules are thought to act as neurotransmitters. The neurotransmitters cross the cleft, binding to receptor molecules on the next cell, prompting transmission of the message along that cell's membrane. Acetylcholine is an example of a neurotransmitter, as is norepinephrine, although each acts in different responses.

Diseases that affect the function of signal transmission can have serious consequences. Parkinson's disease has a deficiency of the neurotransmitter dopamine. Progressive death of brain cells increases this deficit, causing tremors, rigidity and unstable posture. L-dopa is a chemical related to dopamine that eases some of the symptoms (by acting as a substitute neurotransmitter) but cannot reverse the progression of the disease.

### Peripheral Nervous System

The Peripheral Nervous System (PNS) contains only nerves and connects the brain and spinal cord (CNS) to the rest of the body. The axons and dendrites are surrounded by a white myelin sheath. Cell bodies are in the central nervous system (CNS) or ganglia. Ganglia are collections of nerve cell bodies. Cranial nerves in the PNS take impulses to and from the brain (CNS). Spinal nerves take impulses to and away from the spinal cord. There are two major subdivisions of the PNS motor pathways: the somatic and the autonomic.

Two main components of the PNS:

1. sensory (afferent) pathways that provide input from the body into the CNS.
2. motor (efferent) pathways that carry signals to muscles and glands (effectors).

Most sensory input carried in the PNS remains below the level of conscious awareness. Input that does reach the conscious level contributes to perception of our external environment.

### Somatic Nervous System

The Somatic Nervous System (SNS) includes all nerves controlling the muscular system and external sensory receptors. External sense organs (including skin) are receptors. Muscle fibers and gland cells are effectors. The reflex arc is an automatic, involuntary reaction to a stimulus. When the doctor taps your knee with the rubber hammer, she/he is testing your reflex (or knee-jerk). The reaction to the stimulus is involuntary, with the CNS being informed but not consciously controlling the response. Examples of reflex arcs include balance, the blinking reflex, and the stretch reflex.

Sensory input from the PNS is processed by the CNS and responses are sent by the PNS from the CNS to the organs of the body.

Motor neurons of the somatic system are distinct from those of the autonomic system. Inhibitory signals, cannot be sent through the motor neurons of the somatic system.

### Autonomic Nervous System

The Autonomic Nervous System is that part of PNS consisting of motor neurons that control internal organs. It has two subsystems. The autonomic system controls muscles in the heart, the smooth muscle in internal organs such as the intestine, bladder, and uterus. The Sympathetic Nervous System is involved in the fight or flight response. The Parasympathetic Nervous System is involved in relaxation. Each of these subsystems operates in the reverse of the other (antagonism). Both systems innervate the same organs and act in opposition to maintain homeostasis. For example: when you are scared the sympathetic system causes your heart to beat faster; the parasympathetic system reverses this effect.

Motor neurons in this system do not reach their targets directly (as do those in the somatic system) but rather connect to a secondary motor neuron which in turn innervates the target organ.

### Central Nervous System

The Central Nervous System (CNS) is composed of the brain and spinal cord. The CNS is surrounded by bone-skull and vertebrae. Fluid and tissue also insulate the brain and spinal cord.

The brain is composed of three parts: the cerebrum (seat of consciousness), the cerebellum, and the medulla oblongata (these latter two are "part of the unconscious brain").

The medulla oblongata is closest to the spinal cord, and is involved with the regulation of heartbeat, breathing, vasoconstriction (blood pressure), and reflex centers for vomiting, coughing, sneezing, swallowing, and hiccupping. The hypothalamus regulates homeostasis. It has regulatory areas for thirst, hunger, body temperature, water balance, and blood pressure, and links the Nervous System to the Endocrine System. The midbrain and pons are also part of the unconscious brain. The thalamus serves as a central relay point for incoming nervous messages.

The cerebellum is the second largest part of the brain, after the cerebrum. It functions for muscle coordination and maintains normal muscle tone and posture. The cerebellum coordinates balance.

The conscious brain includes the cerebral hemispheres, which are are separated by the corpus callosum. In reptiles, birds, and mammals, the cerebrum coordinates sensory data and motor functions. The cerebrum governs intelligence and reasoning, learning and memory. While the cause of memory is not yet definitely known, studies on slugs indicate learning is accompanied by a synapse decrease. Within the cell, learning involves change in gene regulation and increased ability to secrete transmitters.

### The Brain:

During embryonic development, the brain first forms as a tube, the anterior end of which enlarges into three hollow swellings that form the brain, and the posterior of which develops into the spinal cord. Some parts of the brain have changed little during vertebrate evolutionary history.

Vertebrate evolutionary trends include

1. Increase in brain size relative to body size.
2. Subdivision and increasing specialization of the forebrain, midbrain, and hindbrain.
3. Growth in relative size of the forebrain, especially the cerebrum, which is associated with increasingly complex behavior in mammals.

#### The Brain Stem and Midbrain

The brain stem is the smallest and from an evolutionary viewpoint, the oldest and most primitive part of the brain. The brain stem is continuous with the spinal cord, and is composed of the parts of the hindbrain and midbrain. The medulla oblongata and pons control heart rate, constriction of blood vessels, digestion and respiration.

The midbrain consists of connections between the hindbrain and forebrain. Mammals use this part of the brain only for eye reflexes.

#### The Cerebellum

The cerebellum is the third part of the hindbrain, but it is not considered part of the brain stem. Functions of the cerebellum include fine motor coordination and body movement, posture, and balance. This region of the brain is enlarged in birds and controls muscle action needed for flight.

#### The Forebrain

The forebrain consists of the diencephalon and cerebrum. The thalamus and hypothalamus are the parts of the diencephalon. The thalamus acts as a switching center for nerve messages. The hypothalamus is a major homeostatic center having both nervous and endocrine functions.

The cerebrum, the largest part of the human brain, is divided into left and right hemispheres connected to each other by the corpus callosum. The hemispheres are covered by a thin layer of gray matter known as the cerebral cortex, the most recently evolved region of the vertebrate brain. Fish have no cerebral cortex, amphibians and reptiles have only rudiments of this area.

The cortex in each hemisphere of the cerebrum is between 1 and 4 mm thick. Folds divide the cortex into four lobes: occipital, temporal, parietal, and frontal. No region of the brain functions alone, although major functions of various parts of the lobes have been determined.

The occipital lobe (back of the head) receives and processes visual information. The temporal lobe receives auditory signals, processing language and the meaning of words. The parietal lobe is associated with the sensory cortex and processes information about touch, taste, pressure, pain, and heat and cold. The frontal lobe conducts three functions:

1. motor activity and integration of muscle activity
2. speech
3. thought processes

Most people who have been studied have their language and speech areas on the left hemisphere of their brain. Language comprehension is found in Wernicke's area. Speaking ability is in Broca's area. Damage to Broca's area causes speech impairment but not impairment of language comprehension. Lesions in Wernicke's area impairs ability to comprehend written and spoken words but not speech. The remaining parts of the cortex are associated with higher thought processes, planning, memory, personality and other human activities.

### Forebrain disorders

Region

Disorder

Cerebral cortex

depression, Huntington's disease, mania

Cerebrum

epilepsy, stroke

• frontal lobe

Alzheimer's disease, depression, mania

• parietal lobe

Alzheimer's diseasea

• temporal lobe

Alzheimer's disease, depression, mania

Limbic system

mania

·amygdala

depression

·hippocampus

Alzheimer's

### The Spinal Cord:

The Spinal Cord is connected to the brain and is about the diameter of a human finger. From the brain the spinal cord descends down the middle of the back and is surrounded and protected by the bony vertebral column. The spinal cord is surrounded by a clear fluid called Cerebral Spinal Fluid (CSF), that acts as a cushion to protect the delicate nerve tissues against damage from banging against the inside of the vertebrae.

The anatomy of the spinal cord itself consists of millions of nerve fibers which transmit electrical information to and from the limbs, trunk and organs of the body, back to and from the brain. The brain and spinal cord are referred to as the Central Nervous System, whilst the nerves connecting the spinal cord to the body are referred to as the Peripheral Nervous System.

The nerves within the spinal cord are grouped together in different bundles called Ascending and Descending tracts.

Ascending tracts within the spinal cord carry information from the body, upwards to the brain, such as touch, skin temperature, pain and joint position.

Descending tracts within the spinal cord carry information from the brain downwards to initiate movement and control body functions.

Nerves called the spinal nerves or nerve roots come off the spinal cord and pass out through a hole in each of the vertebrae called the Foramen to carry the information from the spinal cord to the rest of the body, and from the body back up to the brain

There are four main groups of spinal nerves which exit different levels of the spinal cord.

These are in descending order down the vertebral column:

Cervical Nerves "C": (nerves in the neck) supply movement and feeling to the arms, neck and upper trunk.

Thoracic Nerves "T": (nerves in the upper back) supply the trunk and abdomen.

Lumbar Nerves "L" and Sacral Nerves "S": (nerves in the lower back) supply the legs, the bladder, bowel and sexual organs.

The spinal nerves carry information to and from different levels (segments) in the spinal cord. Both the nerves and the segments in the spinal cord are numbered in a similar way to the vertebrae. The point at which the spinal cord ends is called the conus medullaris, and is the terminal end of the spinal cord. It occurs near lumbar nerves L1 and L2. After the spinal cord terminates, the spinal nerves continue as a bundle of nerves called the cauda equina. The upper end of the conus medullaris is usually not well defined.

There are 31 pairs of spinal nerves which branch off from the spinal cord. In the cervical region of the spinal cord, the spinal nerves exit above the vertebrae. A change occurs with the C7 vertebra however, where the C8 spinal nerve exits the vertebra below the C7 vertebra. Therefore, there is an 8th cervical spinal nerve even though there is no 8th cervical vertebra. From the 1st thoracic vertebra downwards, all spinal nerves exit below their equivalent numbered vertebrae.

The spinal nerves which leave the spinal cord are numbered according to the vertebra at which they exit the spinal column. So, the spinal nerve T4, exits the spinal column through the foramen in the 4th thoracic vertebra. The spinal nerve L5 leaves the spinal cord from the conus medullaris, and travels along the cauda equina until it exits the 5th lumbar vertebra.

Source: http://mail.med.upenn.edu/~hessd/Lesson3.htm

### Drugs and the Brain

Some neurotransmitters are excitory, such as acetylcholine, norepinephrine, serotonin, and dopamine. Some are associated with relaxation, such as dopamine and serotonin. Dopamine release seems related to sensations of pleasure. Endorphins are natural opioids that produce elation and reduction of pain, as do artificial chemicals such as opium and heroin. Neurological diseases, for example Parkinson's disease and Huntington's disease, are due to imbalances of neurotransmitters. Parkinson's is due to a dopamine deficiency. Huntington's disease is thought to be cause by malfunctioning of an inhibitory neurotransmitter. Alzheimer's disease is associated with protein plaques in the brain.

### Senses:

Input to the nervous system is in the form of our five senses: pain, vision, taste, smell, and hearing. Vision, taste, smell, and hearing input are the special senses. Pain, temperature, and pressure are known as somatic senses. Sensory input begins with sensors that react to stimuli in the form of energy that is transmitted into an action potential and sent to the CNS.

#### Sensory Receptors

• Sensory receptors are classified according to the type of energy they can detect and respond to.
• Mechanoreceptors: hearing and balance, stretching.
• Photoreceptors: light.
• Chemoreceptors: smell and taste mainly, as well as internal sensors in the digestive and circulatory systems.
• Thermoreceptors: changes in temperature.
• Electroreceptors: detect electrical currents in the surrounding environment

• Mechanoreceptors vary greatly in the specific type of stimulus and duration of stimulus/action potentials. The most adaptable vertebrate mechanoreceptor is the hair cell. Hair cells are present in the lateral line of fish. In humans and mammals hair cells are involved with detection of sound and gravity and providing balance.

#### Hearing

Hearing involves the actions of the external ear, eardrum, ossicles, and cochlea. In hearing, sound waves in air are converted into vibrations of a liquid then into movement of hair cells in the cochlea. Finally they are converted into action potentials in a sensory dendrite connected to the auditory nerve. Very loud sounds can cause violent vibrations in the membrane under hair cells, causing a shearing or permanent distortion to the cells, resulting in permanent hearing loss.

#### Eye

In the eye, two types of photoreceptor cells are clustered on the retina, or back portion of the eye. These receptors, rods and cones, apparently evolved from hair cells. Rods detect differences in light intensity; cones detect color. Rods are more common in a circular zone near the edge of the eye. Cones occur in the center (or fovea centralis) of the retina.

Light reaching a photoreceptor causes the breakdown of the chemical rhodopsin, which in turn causes a membrane potential that is transmitted to an action potential. The action potential transfers to synapsed neurons that connect to the optic nerve. The optic nerve connects to the occipital lobe of the brain.

#### Photoreceptors Detect Vision and Light Sensitivity:

Humans have three types of cones, each sensitive to a different color of light: red, blue and green. Opsins are chemicals that bind to cone cells and make those cells sensitive to light of a particular wavelength (or color). Humans have three different form of opsins coded for by three genes on the X chromosome. Defects in one or more of these opsin genes can cause color blindness, usually in males. The human eye can detect light in the 400-700 nanometer (nm) range, a small portion of the electromagnetic spectrum, the visible light spectrum. Light with wavelengths shorter than 400 nm is termed ultraviolet (UV) light. Light with wavelengths longer than 700 nm is termed infrared (IR) light.

 Nova   Dr. Neil deGrasse Tyson PhD

 PERPETUAL- - - - - - > Motion- - - > motion- - - > You can't have a perpetual motion device, no matter how efficient, it will always lose energy and eventually run down

 Stellar Parallax "Parsec" = 3.26 light years.

 MILKY WAY Consider that our Sun is merely one of  "possibly" 200 Billion stars in the Milky Way Galaxy and if that is not enough, there are several hundred billion Galaxies in the cosmos. End-to-end, the Milky Way galaxy is 100,000 light years (about 30 kiloparsecs in a flattened disk which is about 10,000 light years ( 3 kpc) thick at the center. The sun is some 8.5 kiloparsecs out from the galactic center) across. Traveling to the center of the galaxy, would take 27,000 years, at the speed of light. On a scale, the milky way galaxy is not even a large one. Approximately 6000 stars are visible with the naked eye. Like other spiral galaxies, the Milky Way has a bulge, a disk, and a halo. Although all are parts of the same galaxy, each contains different objects. The halo and central bulge contain old stars and the disk is filled with gas, dust, and young stars. Within our Galaxy exist many star clusters, Omega Centauri, a dense globular cluster of stars is the largest known globular cluster in our galaxy. Within this cluster there are approximately 10 million stars. It is one of about 150 known globular clusters in the Milky Way. Like other spiral galaxies, the Milky Way has a bulge, a disk, and a halo. Although all are parts of the same galaxy, each contains different objects. The halo and central bulge contain old stars and the disk is filled with gas, dust, and young stars. Our Sun is itself a fairly young star at only 5 billion years old. The Milky Way galaxy is at least 5 billion years older than that. The Sun is revolving around the center of the Galaxy at a speed of half a million miles per hour, yet it will still take 200 million years for it to go around once. The halo that surrounds the galaxy represent a low density of old stars mainly in globular clusters (these consist of between 10,000 - 1,000,000 stars). The halo is believed to be composed mainly of dark matter which may extend well beyond the edge of the disk.

 Our nearest Star (other than our Sun) is just a Short Hop Should you wish to travel to our nearest star neighbor, which is 4.3 light years away ( beyond our Sun ), the journey will take you 300 years (a Light year is traveling at 186,280 miles per second, for one year) away, and you will be traveling at a speed of Ten (10) million miles per hour. Of course when you get within ten to twenty million miles from your destination, you will have already burned up.

 PHENOMENA Moving rocks in the Desert: Could it be that those rocks in the desert that move (roll) without wind or any other visible means of force, simply be a situation where, aided with a little nighttime moisture (condensation) rolling down to the bottom of the rock, making contact with thermal heat rising up from within the earth's interior, thus causing a minute amount of lubrication and aided by the pull of the moon or perhaps the Earth's rotation be the culprit?

 QT: Some rare geysers erupt cold water, by the expelling of trapped cardon dioxide under-ground.

 PROPULSION The word propulsion is derived from two Latin words: pro meaning before or forwards and pellere meaning to drive. Propulsion means to push forward or drive an object forward. Electromagnetic: Spacecraft  & Satellite propulsion: Solid propellant pulsed plasma thrusters (PPT) Magnetoplasmadynamic (MPD) thrusters Pulsed inductive thrusters (PIT) Electrothermal: Resistojet: (Dozens of them are currently in orbit helping satellites maintain their orbits, unfortunately, resistojets is that the physical limitations of the conductor means that the maximum temperature they can achieve is 1800 degrees C. Run them hotter than this and they start to melt) Arcjet: An arcjet is simply a resistojet where instead of passing the gas through a heating coil it is passed through an electric arc. Obtaining temperatures of 15,00 degrees C. This way the propellant gets heated to much higher temperatures (typically 3,000 degrees C.) than in resistojets and in so doing achieve higher specific impulses, anywhere from 800 sec for ammonia to 2,000 seconds for hydrogen. Arcjets tend to be higher power devices, typically 1 to 2 kilowatts, and used for higher thrust applications, such as maintaining position stationing of large satellites. Several of these are presently in orbit. Dynamic braking: Utilizing the use of the electric traction motors of a railroad vehicle as generators to slow the vehicle. Fuel Thrust: Four Principal propulsion systems Propeller, Turbine (or jet) engine, Ramjet, and Rocket. (Continuous combustion engines, such as jet engines, most rockets and many gas turbines are also internal combustion engines). On airplanes, thrust is usually generated through some application of Newton's third law of action and reaction. A gas, or working fluid, is accelerated by the engine, and the reaction to this acceleration produces a force on the engine. A general derivation of the thrust equation shows that the amount of thrust generated depends on the mass flow through the engine and the exit velocity of the gas. Different propulsion systems generate thrust in slightly different ways. If we think about Newton's first law of motion, we realize that an airplane propulsion system must serve two purposes. First, the thrust from the propulsion system must balance the drag of the airplane when the airplane is cruising. And second, the thrust from the propulsion system must exceed the drag of the airplane for the airplane to accelerate. In fact, the greater the difference between the thrust and the drag, called the excess thrust, the faster the airplane will accelerate. Some aircraft, like airliners and cargo planes, spend most of their life in a cruise condition. For these airplanes, excess thrust is not as important as high engine efficiency and low fuel usage. Since thrust depends on both the amount of gas moved and the velocity, we can generate high thrust by accelerating a large mass of gas by a small amount, or by accelerating a small mass of gas by a large amount. Because of the aerodynamic efficiency of propellers and fans, it is more fuel efficient to accelerate a large mass by a small amount. That is why we find high bypass fans and turboprops on cargo planes and airliners. Some aircraft, like fighter planes or experimental high speed aircraft, require very high excess thrust to accelerate quickly and to overcome the high drag associated with high speeds. For these airplanes, engine efficiency is not as important as very high thrust. Modern military aircraft typically employ afterburners on a low bypass turbofan core. Most likely, future hypersonic aircraft will employ some type of ramjet or rocket propulsion. Laser Launch Systems: The laser beam is used to heat a propellant with the energetic expansion driving the craft. Nuclear energy: Although containment weight would be a real challenge, but is certainly possible.

 PROTEINS Although DNA is the carrier of genetic information in a cell, proteins do most of the work. Proteins are long chains containing as many as 20 different kinds of amino acids. Each cell contains thousands of different proteins: enzymes that make new molecules and catalyze nearly all chemical processes in cells; structural components that give cells their shape and help them move; hormones that transmit signals throughout the body; antibodies that recognize foreign molecules; and transport molecules that carry oxygen. The genetic code carried by DNA is what specifies the order and number of amino acids and, therefore, the shape and function of the protein. See DNA  or   RNA

 PYROCLASIC FLOWS Pyroclastic flows are high-density mixtures of hot, dry rock fragments and hot gases that move away from the vent that erupted them at high speeds. They may result from the explosive eruption of molten or solid rock fragments, or both. They may also result from the nonexplosive eruption of lava when parts of dome or a thick lava flow collapses down a steep slope. Most pyroclastic flows consist of two parts: a basal flow of coarse fragments that moves along the ground, and a turbulent cloud of ash that rises above the basal flow. Ash may fall from this cloud over a wide area downwind from the pyroclastic flow. Scientists use a wide variety of names to describe specific types of hot, dry flows of rock fragments and gas produced by erupting volcanoes. The terms below are used to describe either (1) the way in which a pyroclastic flow originates and moves; or (2) a predominant characteristic of the resulting deposit. Ash Flow or Ash Cloud A pyroclastic flow consisting primarily of ash-sized particles, including glass shards and mineral fragments Block and Ash Flow A pyroclastic flow consisting of ash and large lava fragments with few gas bubbles, which typically forms as a consequence of a collapsing lava flow or dome. Base Surge A turbulent, low-density flow of rock debris and water and (or) steam that moves at high speeds. Base surges may occur when an explosive eruption occurs from within a crater lake or an ocean. Directed Blast A volcanic explosion of rocks and magma (or both) with a low-angle component. When the rock debris from a directed blast falls to the ground, it behaves like a pyroclastic flow or surge and moves rapidly away from the volcano. Nuée Ardente (glowing cloud) When viewed at night or in low light, pyroclastic flows may appear to glow red. The term is widely used to describe pyroclastic flows, but not to imply the way a flow is generated. Pumice Flow A pyroclastic flow consisting predominantly of pumice fragments, which contain many gas bubbles. Pyroclastic Surge A turbulent, low-density cloud of hot rock debris and gases that moves at extremely high speeds. Because surges are low density, they tend to spread over large areas and move up and over ridge crests easily. By contrast, pyroclastic flows are high-density masses of hot rock debris and gases that tend to be confined in valleys (Pyroclastic flows are high-density mixtures of hot, dry rock fragments and hot gases that move away from the vent that erupted them at high speeds. They may result from the explosive eruption of molten or solid rock fragments, or both. They may also result from the nonexplosive eruption of lava when parts of dome or a thick lava flow collapses down a steep slope. Most pyroclastic flows consist of two parts: a basal flow of coarse fragments that moves along the ground, and a turbulent cloud of ash that rises above the basal flow. Ash may fall from this cloud over a wide area downwind from the pyroclastic flow.) A good example of a "surge" is that of  Mt. St. Helens. The landslide depressurized the volcano's magma system, triggering powerful explosions that ripped through the sliding debris. Rocks, ash, volcanic gas, and steam were blasted upward and outward to the north. The directed blast of hot material, called a pyroclastic surge by scientists, accelerated to nearly 500 km per hour (300 miles per hour), then slowed as rocks and ash fell to the ground and spread away from the volcano.

 Quantum-Relativity Quantum Physics deals with the very small and Relativity pertains to the larger universe beyond. BillNye.com

Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay.

Radioactive decay rates are normally stated in terms of their half-lives**, and the half-life of a given nuclear species is related to its radiation risk. The different types of radioactivity lead to different decay paths which transmute the nuclei into other chemical elements. Examining the amounts of the decay products makes possible radioactive dating.

**Half-lives (t ½ ) can be VERY short (helium-5 decays in 7.6 x 10-22 seconds), or very long (thorium-232 decays in 1.4 billion years).

The half-life is the amount of time that it will take half of the atoms to decay.  This does not mean that in twice that amount of time, all the atoms will decay.  Since this is a random process, there is no history and you have to start over, so in the second half-life, half of the remaining atoms will decay, leaving a quarter of the original atoms.

Note:  All the atoms will still be there, but the ones that have decayed will be a different element.

Radiation from nuclear sources is distributed equally in all directions, obeying the inverse square law.

When an unstable nucleus decays, there are three ways that it can do so.
It may give out -

-an alpha particle (the symbol "a")
-a beta particle (symbol "b")
-a gamma ray (symbol "g")

Many radioactive substances emit a particles and "b" particles as well as "g" rays.
There is not a pure "g" source; anything that gives off "g" rays will also give off "a" and or/ "b" also.

Alpha particles are made of 2 protons and 2 neutrons.

This means that they have a charge of +2, and a mass of 4
(the mass is measured in "atomic mass units", where each proton & neutron=1)

Alpha particles are relatively slow and heavy.

They have a low penetrating power - you can stop them with just a sheet of paper.

Because they have a large charge, alpha particles ionize other atoms strongly.

Beta particles have a charge of minus 1, and a mass of about 1/2000th of a proton. This means that beta particles are the same as an electron.

They are fast, and light.

Beta particles have a medium penetrating power - they are stopped by a sheet of aluminum or plastics such as perspex.

Beta particles ionize atoms that they pass, but not as strongly as Alpha particles do.

Gamma rays are waves, not particles. This means that they have no mass and no charge.

Gamma rays have a high penetrating power - it takes a thick sheet of metal such as lead, or concrete to reduce them significantly.

Gamma rays do not directly ionize other atoms, although they may cause atoms to emit other particles which will then cause ionisation.

We don't find pure gamma sources - gamma rays are emitted alongside alpha or beta particles. Strictly speaking, gamma emission isn't 'radioactive decay' because it doesn't change the state of the nucleus; it just carries away some energy.

• Alpha particles are easy to stop; gamma rays are hard to stop.

• Particles that ionize other atoms strongly have a low penetrating power, because they lose energy each time they ionise an atom.
• Radioactive decay is not affected by external conditions.

Just because something is called an isotope doesn't necessarily mean it's radioactive.
You can think of different isotopes of an atom being different "versions" of that atom.

Consider a carbon atom. It has 6 protons and 6 neutrons - we call it "carbon-12" because it has an atomic mass of 12 (6 plus 6).
If we add a neutron, it's still a carbon atom, but it's a different isotope of carbon. One useful isotope of carbon is "carbon-14", which has 6 protons and 8 neutrons. This is the atom we look for when we're carbon dating an object.

Isotopes of an atom have the same number of protons, but a different number of neutrons.

 Type of Radiation Alpha particle Beta particle Gamma ray Symbol a b g (can look different, depends on the font) Mass (atomic mass units) 4 1/2000 0 Charge +2 -1 0 Speed slow fast very fast (speed of light) Ionising ability high medium 0 Penetrating power low medium high Stopped by: paper aluminum lead

# Deuterium-Tritium Fusion

The most promising of the hydrogen fusion reactions which make up the deuterium cycle is the fusion of deuterium and tritium. The reaction yields 17.6 MeV of energy but requires a temperature of approximately 40 million Kelvin’s to overcome the coulomb barrier and ignite it. The deuterium fuel is abundant, but tritium must be either bred from lithium or gotten in the operation of the deuterium cycle.

# Hydrogen Fusion Reactions

Even though a lot of energy is required to overcome the Coulomb barrier and initiate hydrogen fusion, the energy yields are enough to encourage continued research. Hydrogen fusion on the earth could make use of the reactions:

These reactions are more promising than the proton-proton fusion of the stars for potential energy sources. Of these the deuterium-tritium fusion appears to be the most promising and has been the subject of most experiments. In a deuterium-deuterium reactor, another reaction could also occur, creating a deuterium cycle:

# Tritium Breeding

Deuterium-Tritium fusion is the most promising of the hydrogen fusion reactions, but no tritium occurs in nature since it has a 10 year half-life. The most promising source of tritium seems to be the breeding of tritium from lithium-6 by neutron bombardment with the reaction which can be achieved by slow neutrons. This would occur if lithium were used as the coolant and heat transfer medium around the reaction chamber of a fusion reactor. Lithium-6 makes up 7.4% of natural lithium. While this constitutes a sizable supply, it is the limiting resource for the D-T process since the supply of deuterium fuel is virtually unlimited. With fast neutrons, tritium can be bred from the more abundant Li-7:

# Deuterium Source

Since the most practical nuclear fusion reaction for power generation seems to be the deuterium-tritium reaction, the sources of these fuels are important. The deuterium part of the fuel does not pose a great problem because about 1 part in 5000 of the hydrogen in seawater is deuterium. This amounts to over 10^15 tons of deuterium. Viewed as a potential fuel for a fusion reactor, a gallon of seawater could produce as much energy as 300 gallons of gasoline. The tritium part of the fuel is more problematic - there is no sizable natural source since tritium is radioactive with a half-life of about 10 years. It would have to be obtained by breeding the tritium from lithium.

# Nuclear Fission

Fission only happens with heavy elements.

The simplest type of fission is called alpha-decay.  A group of two protons and two neutrons (called an “alpha particle”, which is basically a helium nucleus) splits off and the rest of the nucleus remain as a whole.

Fission can also result in the nucleus splitting into a bunch of fragments of varying sizes.

Fission is sometimes called Spontaneous Fission to distinguish it from Induced Fission, which is when you hit the nucleus with a projectile such as a neutron.  Induced fission is responsible for most of the reactions in nuclear power plants and nuclear bombs.

If a massive nucleus like uranium-235 breaks apart (fissions), then there will be a net yield of energy because the sum of the masses of the fragments will be less than the mass of the uranium nucleus. If the mass of the fragments is equal to or greater than that of iron at the peak of the binding energy curve, then the nuclear particles will be more tightly bound than they were in the uranium nucleus, and that decrease in mass comes off in the form of energy according to the Einstein equation. For elements lighter than iron, fusion will yield energy.

The fission of U-235 in reactors is triggered by the absorption of a low energy neutron, often termed a "slow neutron" or a "thermal neutron". Other fissionable isotopes which can be induced to fission by slow neutrons are plutonium-239, uranium-233, and thorium-232.

# Nuclear Fusion

If light nuclei are forced together, they will fuse with a yield of energy because the mass of the combination will be less than the sum of the masses of the individual nuclei. If the combined nuclear mass is less than that of iron at the peak of the binding energy curve, then the nuclear particles will be more tightly bound than they were in the lighter nuclei, and that decrease in mass comes off in the form of energy according to the Einstein relationship. For elements heavier than iron, fission will yield energy.

For potential nuclear energy sources for the Earth, the deuterium-tritium fusion reaction contained by some kind of magnetic confinement seems the most likely path. However, for the fueling of the stars, other fusion reactions will dominate.

# Light Water Reactors

The nuclear fission reactors used in the United States for electric power production are classified as "light water reactors" in contrast to the "heavy water reactors" used in Canada. Light water (ordinary water) is used as the moderator in U.S. reactors as well as the cooling agent and the means by which heat is removed to produce steam for turning the turbines of the electric generators. The use of ordinary water makes it necessary to do a certain amount of enrichment of the uranium fuel before the necessary criticality of the reactor can be maintained.

The two varieties of the light water reactor are the pressurized water reactor (PWR) and boiling water reactor (BWR).

# Fusion Reactors

Reactors for nuclear fusion are of two main varieties, magnetic confinement reactors and inertial confinement reactors. The strategies for creating fusion reactors are largely dictated by the fact that the temperatures involved in nuclear fusion are far too high to be contained in any material container.

The strategy of the magnetic confinement reactor is to confine the hot plasma by means of magnetic fields which keep it perpetually in looping paths which do not touch the wall of the container. This is typified by the tokamak design, the most famous example of which is the TFTR at Princeton.

The strategy of the inertial confinement reactor is to put such high energy density into a small pellet of deuterium-tritium that it fuses in such a short time that it can't move appreciably. The most advanced test reactors involve laser fusion, particularly in the Shiva and Nova reactors at Lawrence Livermore Laboratories.

# Fast Breeder Reactors

Under appropriate operating conditions, the neutrons given off by fission reactions can "breed" more fuel from otherwise non-fissionable isotopes. The most common breeding reaction is that of plutonium-239 from non-fissionable uranium-238. The term "fast breeder" refers to the types of configurations which can actually produce more fissionable fuel than they use, such as the LMFBR. This scenario is possible because the non-fissionable uranium-238 is 140 times more abundant than the fissionable U-235 and can be efficiently converted into Pu-239 by the neutrons from a fission chain reaction.

France has made the largest implementation of breeder reactors ( it halted electricity production in 1996 and was closed as a commercial plant in 1997) with its large Super-Phenix reactor and an intermediate scale reactor (BN-600) on the Caspian Sea for electric power and desalinization.

## A

Absolute risk: the proportion of a population expected to get a disease over a specified time period.

Absorbed dose: the amount of energy deposited by ionizing radiation in a unit mass of tissue. It is expressed in units of joule per kilogram (J/kg), and called “gray” (Gy).

Activity (radioactivity): the rate of decay of radioactive material expressed as the number of atoms breaking down per second measured in units called becquerels or curies.

Acute exposure: an exposure to radiation that occurred in a matter of minutes rather than in longer, continuing exposure over a period of time.

Acute Radiation Syndrome (ARS): a serious illness caused by receiving a dose greater than 75 rads of penetrating radiation to the body in a short time (usually minutes). The earliest symptoms are nausea, fatigue, vomiting, and diarrhea. Hair loss, bleeding, swelling of the mouth and throat, and general loss of energy may follow. If the exposure has been approximately 1,000 rads or more, death may occur within 2 – 4 weeks.

Air burst: a nuclear weapon explosion that is high enough in the air to keep the fireball from touching the ground. Because the fireball does not reach the ground and does not pick up any surface material, the radioactivity in the fallout from an air burst is relatively insignificant compared with a surface burst.

Alpha particle: the nucleus of a helium atom, made up of two neutrons and two protons with a charge of +2. Certain radioactive nuclei emit alpha particles. Alpha particles generally carry more energy than gamma or beta particles, and deposit that energy very quickly while passing through tissue. Alpha particles can be stopped by a thin layer of light material, such as a sheet of paper, and cannot penetrate the outer, dead layer of skin. Therefore, they do not damage living tissue when outside the body. When alpha-emitting atoms are inhaled or swallowed, however, they are especially damaging because they transfer relatively large amounts of ionizing energy to living cells.

Ambient air: the air that surrounds us.

Americium (Am): a silvery metal; it is a man-made element whose isotopes Am-237 through Am-246 are all radioactive. Am-241 is formed spontaneously by the beta decay of plutonium-241. Trace quantities of americium are widely used in smoke detectors, and as neutron sources in neutron moisture gauges.

Atom: the smallest particle of an element that can enter into a chemical reaction.

Atomic number: the total number of protons in the nucleus of an atom.

Atomic mass unit (amu): 1 amu is equal to one twelfth of the mass of a carbon-12 atom.

Atomic mass number: the total number of protons and neutrons in the nucleus of an atom.

Atomic weight: the mass of an atom, expressed in atomic mass units. For example, the atomic number of helium-4 is 2, the atomic mass is 4, and the atomic weight is 4.00026.

## B

Becquerel (Bq): the amount of a radioactive material that will undergo one decay (disintegration) per second.

Beta particles: electrons ejected from the nucleus of a decaying atom. Although they can be stopped by a thin sheet of aluminum, beta particles can penetrate the dead skin layer, potentially causing burns. They can pose a serious direct or external radiation threat and can be lethal depending on the amount received. They also pose a serious internal radiation threat if beta-emitting atoms are ingested or inhaled.

Bioassay: an assessment of radioactive materials that may be present inside a person’s body through analysis of the person’s blood, urine, feces, or sweat.

Biological Effects of Ionizing Radiation (BEIR) Reports: reports of the National Research Council's committee on the Biological Effects of Ionizing Radiation.

Biological half-life: the time required for one half of the amount of a substance, such as a radionuclide, to be expelled from the body by natural metabolic processes, not counting radioactive decay, once it has been taken in through inhalation, ingestion, or absorption. .

## C

Carcinogen: a cancer-causing substance.

Chain reaction: a process that initiates its own repetition. In a fission chain reaction, a fissile nucleus absorbs a neutron and fissions (splits) spontaneously, releasing additional neutrons. These, in turn, can be absorbed by other fissile nuclei, releasing still more neutrons. A fission chain reaction is self-sustaining when the number of neutrons released in a given time equals or exceeds the number of neutrons lost by absorption in non-fissile material or by escape from the system.

Chronic exposure: exposure to a substance over a long period of time, possibly resulting in adverse health effects.

Cobalt (Co): gray, hard, magnetic, and somewhat malleable metal. Cobalt is relatively rare and generally obtained as a byproduct of other metals, such as copper. Its most common radioisotope, cobalt-60 (Co-60), is used in radiography and medical applications. Cobalt-60 emits beta particles and gamma rays during radioactive decay.

Collective dose: the estimated dose for an area or region multiplied by the estimated population in that area or region.

Committed dose: a dose that accounts for continuing exposures expected to be received over a long period of time (such as 30, 50, or 70 years) from radioactive materials that were deposited inside the body.

Concentration: the ratio of the amount of a specific substance in a given volume or mass of solution to the mass or volume of solvent.
.

Contamination (radioactive): the deposition of unwanted radioactive material on the surfaces of structures, areas, objects, or people where it may be external or internal.

Cosmic radiation: radiation produced in outer space when heavy particles from other galaxies (nuclei of all known natural elements) bombard the earth.

Criticality: a fission process where the neutron production rate equals the neutron loss rate to absorption or leakage. A nuclear reactor is "critical" when it is operating.

Critical mass: the minimum amount of fissile material that can achieve a self-sustaining nuclear chain reaction.

Cumulative dose: the total dose resulting from repeated or continuous exposures of the same portion of the body, or of the whole body, to ionizing radiation.

Curie (Ci): the traditional measure of radioactivity based on the observed decay rate of 1 gram of radium. One curie of radioactive material will have 37 billion disintegrations in 1 second.

Cutaneous Radiation Syndrome (CRS): the complex syndrome resulting from radiation exposure of more than 200 rads to the skin. The immediate effects can be reddening and swelling of the exposed area (like a severe burn), blisters, ulcers on the skin, hair loss, and severe pain. Very large doses can result in permanent hair loss, scarring, altered skin color, deterioration of the affected body part, and death of the affected tissue (requiring surgery).

## D

Decay chain (decay series): the series of decays that certain radioisotopes go through before reaching a stable form. For example, the decay chain that begins with uranium-238 (U-238) ends in lead-206 (Pb-206), after forming isotopes, such as uranium-234 (U-234), thorium-230 (Th-230), radium-226 (Ra-226), and radon-222 (Rn-222).

Decay constant: the fraction of a number of atoms of a radioactive nuclide that disintegrates in a unit of time. The decay constant is inversely proportional to the radioactive half-life.

Decay products (or daughter products): the isotopes or elements formed and the particles and high-energy electromagnetic radiation emitted by the nuclei of radionuclides during radioactive decay. Also known as "decay chain products" or "progeny" (the isotopes and elements). A decay product may be either radioactive or stable.

Decay, radioactive: disintegration of the nucleus of an unstable atom by the release of radiation.

Decontamination: the reduction or removal of radioactive contamination from a structure, object, or person.

Depleted uranium: uranium containing less than 0.7% uranium-235, the amount found in natural uranium. .

Deposition density: the activity of a radionuclide per unit area of ground. Reported as becquerels per square meter or curies per square meter.

Deterministic effects: effects that can be related directly to the radiation dose received. The severity increases as the dose increases. A deterministic effect typically has a threshold below which the effect will not occur. See also stochastic effect, non-stochastic effect.

Deuterium: a non-radioactive isotope of the hydrogen atom that contains a neutron in its nucleus in addition to the one proton normally seen in hydrogen. A deuterium atom is twice as heavy as normal hydrogen. See also tritium.

Dirty bomb: a device designed to spread radioactive material by conventional explosives when the bomb explodes. A dirty bomb kills or injures people through the initial blast of the conventional explosive and spreads radioactive contamination over possibly a large area—hence the term “dirty.” Such bombs could be miniature devices or large truck bombs. A dirty bomb is much simpler to make than a true nuclear weapon.

Dose coefficient: the factor used to convert radionuclide intake to dose. Usually expressed as dose per unit intake (e.g., sieverts per becquerel).

Dose equivalent: a quantity used in radiation protection to place all radiation on a common scale for calculating tissue damage. Dose equivalent is the absorbed dose in grays times the quality factor. The quality factor accounts for differences in radiation effects caused by different types of ionizing radiation. Some radiation, including alpha particles, causes a greater amount of damage per unit of absorbed dose than other radiation. The sievert (Sv) is the unit used to measure dose equivalent. For more information, see “Primer on Radiation Measurement” at the end of this document.

Dose rate: the radiation dose delivered per unit of time.

Dose reconstruction: a scientific study that estimates doses to people from releases of radioactivity or other pollutants. The dose is reconstructed by determining the amount of material released, the way people came in contact with it, and the amount they absorbed.

Dosimeter: a small portable instrument (such as a film badge, thermoluminescent dosimeter [TLD], or pocket dosimeter) for measuring and recording the total accumulated dose of ionizing radiation a person receives.

Dosimetry: assessment (by measurement or calculation) of radiation dose.

## E

Effective dose: a dosimetric quantity useful for comparing the overall health affects of irradiation of the whole body. It takes into account the absorbed doses received by various organs and tissues and weighs them according to present knowledge of the sensitivity of each organ to radiation. It also accounts for the type of radiation and the potential for each type to inflict biologic damage. The effective dose is used, for example, to compare the overall health detriments of different radionuclides in a given mix. The unit of effective dose is the sievert (Sv); 1 Sv = 1 J/kg.

Effective half-life: the time required for the amount of a radionuclide deposited in a living organism to be diminished by 50% as a result of the combined action of radioactive decay and biologic elimination.

Electron: an elementary particle with a negative electrical charge and a mass 1/1837 that of the proton. Electrons surround the nucleus of an atom because of the attraction between their negative charge and the positive charge of the nucleus. A stable atom will have as many electrons as it has protons. The number of electrons that orbit an atom determine its chemical properties.

Element: 1) all isotopes of an atom that contain the same number of protons. For example, the element uranium has 92 protons, and the different isotopes of this element may contain 134 to 148 neutrons. 2) In a reactor, a fuel element is a metal rod containing the fissile material.

Enriched uranium: uranium in which the proportion of the isotope uranium-235 has been increased by removing uranium-238 mechanically.

Exposure (radiation): a measure of ionization in air caused by x-rays or gamma rays only. The unit of exposure most often used is the roentgen.

Exposure pathway: a route by which a radionuclide or other toxic material can enter the body. The main exposure routes are inhalation, ingestion, absorption through the skin, and entry through a cut or wound in the skin.

Exposure rate: a measure of the ionization produced in air by x-rays or gamma rays per unit of time (frequently expressed in roentgens per hour).

External exposure: exposure to radiation outside of the body.

## F

Fallout, nuclear: minute particles of radioactive debris that descend slowly from the atmosphere after a nuclear explosion.

Fissile material: any material in which neutrons can cause a fission reaction. The three primary fissile materials are uranium-233, uranium-235, and plutonium-239.

Fission (fissioning): the splitting of a nucleus into at least two other nuclei that releases a large amount of energy. Two or three neutrons are usually released during this transformation. See also fusion.

Fractionated exposure: exposure to radiation that occurs in several small acute exposures, rather than continuously as in a chronic exposure.

Fusion: a reaction in which at least one heavier, more stable nucleus is produced from two lighter, less stable nuclei. Reactions of this type are responsible for the release of energy in stars or in thermonuclear weapons.

## G

Gamma rays: high-energy electromagnetic radiation emitted by certain radionuclides when their nuclei transition from a higher to a lower energy state. These rays have high energy and a short wave length. All gamma rays emitted from a given isotope have the same energy, a characteristic that enables scientists to identify which gamma emitters are present in a sample. Gamma rays penetrate tissue farther than do beta or alpha particles, but leave a lower concentration of ions in their path to potentially cause cell damage. Gamma rays are very similar to x-rays.

Geiger counter: a radiation detection and measuring instrument consisting of a gas-filled tube containing electrodes, between which an electrical voltage but no current flows. When ionizing radiation passes through the tube, a short, intense pulse of current passes from the negative electrode to the positive electrode and is measured or counted. The number of pulses per second measures the intensity of the radiation field. Geiger counters are the most commonly used portable radiation detection instruments.

Genetic effects: hereditary effects (mutations) that can be passed on through reproduction because of changes in sperm or ova.

Gray (Gy): a unit of measurement for absorbed dose. It measures the amount of energy absorbed in a material. The unit Gy can be used for any type of radiation, but it does not describe the biological effects of the different radiations.

Half-life: the time any substance takes to decay by half of its original amount.

High-level radioactive waste: the radioactive material resulting from spent nuclear fuel reprocessing. This can include liquid waste directly produced in reprocessing or any solid material derived from the liquid wastes having a sufficient concentration of fission products. Other radioactive materials can be designated as high-level waste, if they require permanent isolation. This determination is made by the U.S. Nuclear Regulatory Commission on the basis of criteria established in U.S. law.

Hot spot: any place where the level of radioactive contamination is considerably greater than the area around it.

## I

Ingestion: 1) the act of swallowing; 2) in the case of radionuclides or chemicals, swallowing radionuclides or chemicals by eating or drinking.

Inhalation: 1) the act of breathing in; 2) in the case of radionuclides or chemicals, breathing in radionuclides or chemicals.

Internal exposure: exposure to radioactive material taken into the body.

Iodine: a nonmetallic solid element. There are both radioactive and non-radioactive isotopes of iodine. Radioactive isotopes of iodine are widely used in medical applications. Radioactive iodine is a fission product and is the largest contributor to people’s radiation dose after an accident at a nuclear reactor.

Ion: an atom that has fewer or more electrons than it has protons causing it to have an electrical charge and, therefore, be chemically reactive.

Ionization: the process of adding one or more electrons to, or removing one or more electrons from, atoms or molecules, thereby creating ions. High temperatures, electrical discharges, or nuclear radiation can cause ionization.

any radiation capable of displacing electrons from atoms, thereby producing ions. High doses of ionizing radiation may produce severe skin or tissue damage. See also alpha particle, beta particle, gamma ray, neutron, x-ray.

Isotope: a nuclide of an element having the same number of protons but a different number of neutrons.

## K

Kiloton (Kt): the energy of an explosion that is equivalent to an explosion of 1,000 tons of TNT. One kiloton equals 1 trillion (1012) calories. See also megaton.

## L

Latent period: the time between exposure to a toxic material and the appearance of a resultant health effect.

Lead (Pb): a heavy metal. Several isotopes of lead, such as Pb-210 which emits beta radiation, are in the uranium decay chain.

Local radiation injury (LRI): acute radiation exposure (more than 1,000 rads) to a small, localized part of the body. Most local radiation injuries do not cause death. However, if the exposure is from penetrating radiation (neutrons, x-rays, or gamma rays), internal organs may be damaged and some symptoms of acute radiation syndrome (ARS), including death, may occur. Local radiation injury invariably involves skin damage, and a skin graft or other surgery may be required.

Low-level waste (LLW): radioactively contaminated industrial or research waste such as paper, rags, plastic bags, medical waste, and water-treatment residues. It is waste that does not meet the criteria for any of three other categories of radioactive waste: spent nuclear fuel and high-level radioactive waste; transuranic radioactive waste; or uranium mill tailings. Its categorization does not depend on the level of radioactivity it contains.

## M

Megaton (Mt): the energy of an explosion that is equivalent to an explosion of 1 million tons of TNT. One megaton is equal to a quintillion (1018) calories. See also kiloton.

Molecule: a combination of two or more atoms that are chemically bonded. A molecule is the smallest unit of a compound that can exist by itself and retain all of its chemical properties.

## N

Neoplastic: pertaining to the pathologic process resulting in the formation and growth of an abnormal mass of tissue.

Neutron: a small atomic particle possessing no electrical charge typically found within an atom's nucleus. Neutrons are, as the name implies, neutral in their charge. That is, they have neither a positive nor a negative charge. A neutron has about the same mass as a proton. See also alpha particle, beta particle, gamma ray, nucleon, x-ray.

Non-ionizing radiation: radiation that has lower energy levels and longer wavelengths than ionizing radiation. It is not strong enough to affect the structure of atoms it contacts but is strong enough to heat tissue and can cause harmful biological effects. Examples include radio waves, microwaves, visible light, and infrared from a heat lamp.

Non-stochastic effects: effects that can be related directly to the radiation dose received. The effect is more severe with a higher dose. It typically has a threshold, below which the effect will not occur. These are sometimes called deterministic effects. For example, a skin burn from radiation is a non-stochastic effect that worsens as the radiation dose increases. See also stochastic effects.

Nuclear energy: the heat energy produced by the process of nuclear fission within a nuclear reactor or by radioactive decay.

Nuclear fuel cycle: the steps involved in supplying fuel for nuclear power plants. It can include mining, milling, isotopic enrichment, fabrication of fuel elements, use in reactors, chemical reprocessing to recover the fissile material remaining in the spent fuel, reenrichment of the fuel material refabrication into new fuel elements, and waste disposal.

Nuclear tracers: radioisotopes that give doctors the ability to "look" inside the body and observe soft tissues and organs, in a manner similar to the way x-rays provide images of bones. A radioactive tracer is chemically attached to a compound that will concentrate naturally in an organ or tissue so that an image can be taken.

Nucleon: a proton or a neutron; a constituent of the nucleus of an atom.

Nucleus: the central part of an atom that contains protons and neutrons. The nucleus is the heaviest part of the atom.

Nuclide: a general term applicable to all atomic forms of an element. Nuclides are characterized by the number of protons and neutrons in the nucleus, as well as by the amount of energy contained within the atom.

## P

Pathways: the routes by which people are exposed to radiation or other contaminants. The three basic pathways are inhalation, ingestion, and direct external exposure.

Penetrating radiation: radiation that can penetrate the skin and reach internal organs and tissues. Photons (gamma rays and x-rays), neutrons, and protons are penetrating radiations. However, alpha particles and all but extremely high-energy beta particles are not considered penetrating radiation.

Photon: discrete "packet" of pure electromagnetic energy. Photons have no mass and travel at the speed of light. The term "photon" was developed to describe energy when it acts like a particle (causing interactions at the molecular or atomic level), rather than a wave. Gamma rays and x-rays are photons.

Pitchblende: a brown to black mineral that has a distinctive luster. It consists mainly of urananite (UO2), but also contains radium (Ra). It is the main source of uranium (U) ore.

Plume: the material spreading from a particular source and traveling through environmental media, such as air or ground water. For example, a plume could describe the dispersal of particles, gases, vapors, and aerosols in the atmosphere, or the movement of contamination through an aquifer (For example, dilution, mixing, or adsorption onto soil).

Plutonium (Pu): a heavy, man-made, radioactive metallic element. The most important isotope is Pu-239, which has a half-life of 24,000 years. Pu-239 can be used in reactor fuel and is the primary isotope in weapons. One kilogram is equivalent to about 22 million kilowatt-hours of heat energy. The complete detonation of a kilogram of plutonium produces an explosion equal to about 20,000 tons of chemical explosive. All isotopes of plutonium are readily absorbed by the bones and can be lethal depending on the dose and exposure time.

Polonium (Po): a radioactive chemical element and a product of radium (Ra) decay. Polonium is found in uranium (U) ores.

Prenatal radiation exposure: radiation exposure to an embryo or fetus while it is still in its mother’s womb. At certain stages of the pregnancy, the fetus is particularly sensitive to radiation and the health consequences could be severe above 5 rads, especially to brain function.

Proton: a small atomic particle, typically found within an atom's nucleus, that possesses a positive electrical charge. Even though protons and neutrons are about 2,000 times heavier than electrons, they are tiny. The number of protons is unique for each chemical element. See also nucleon.

## Q

Quality factor (Q): the factor by which the absorbed dose (rad or gray) is multiplied to obtain a quantity that expresses, on a common scale for all ionizing radiation, the biological damage (rem) to an exposed person. It is used because some types of radiation, such as alpha particles, are more biologically damaging internally than other types.

## R

Rad (radiation absorbed dose): a basic unit of absorbed radiation dose. It is a measure of the amount of energy absorbed by the body. The rad is the traditional unit of absorbed dose. It is being replaced by the unit gray (Gy), which is equivalent to 100 rad. One rad equals the dose delivered to an object of 100 ergs of energy per gram of material.

Radiation: energy moving in the form of particles or waves. Familiar radiations are heat, light, radio waves, and microwaves. Ionizing radiation is a very high-energy form of electromagnetic radiation.

Radiation warning symbol: a symbol prescribed by the Code of Federal Regulations. It is a magenta or black trefoil on a yellow background. It must be displayed where certain quantities of radioactive materials are present or where certain doses of radiation could be received.

Radioactive contamination: the deposition of unwanted radioactive material on the surfaces of structures, areas, objects, or people. It can be airborne, external, or internal.

Radioactive decay: the spontaneous disintegration of the nucleus of an atom.

Radioactive half-life: the time required for a quantity of a radioisotope to decay by half. For example, because the half-life of iodine-131 (I-131) is 8 days, a sample of I-131 that has 10 mCi of activity on January 1, will have 5 mCi of activity 8 days later, on January 9.

Radioactivity: the process of spontaneous transformation of the nucleus, generally with the emission of alpha or beta particles often accompanied by gamma rays. This process is referred to as decay or disintegration of an atom.

Radioassay: a test to determine the amounts of radioactive materials through the detection of ionizing radiation. Radioassays will detect transuranic nuclides, uranium, fission and activation products, naturally occurring radioactive material, and medical isotopes.

Radiography: 1) medical: the use of radiant energy (such as x-rays and gamma rays) to image body systems. 2) industrial: the use of radioactive sources to photograph internal structures, such as turbine blades in jet engines. A sealed radiation source, usually iridium-192 (Ir-192) or cobalt-60 (Co-60), beams gamma rays at the object to be checked. Gamma rays passing through flaws in the metal or incomplete welds strike special photographic film (radiographic film) on the opposite side.

Radioisotope (radioactive isotope): isotopes of an element that have an unstable nucleus. Radioactive isotopes are commonly used in science, industry, and medicine. The nucleus eventually reaches a stable number of protons and neutrons through one or more radioactive decays. Approximately 3,700 natural and artificial radioisotopes have been identified.

Radiological dispersal device (RDD): a device that disperses radioactive material by conventional explosive or other mechanical means, such as a spray. See also dirty bomb.

Radium (Ra): a naturally occurring radioactive metal. Radium is a radionuclide formed by the decay of uranium (U) and thorium (Th) in the environment. It occurs at low levels in virtually all rock, soil, water, plants, and animals. Radon (Rn) is a decay product of radium.

Radon (Rn): a naturally occurring radioactive gas found in soils, rock, and water throughout the United States. Radon causes lung cancer and is a threat to health because it tends to collect in homes, sometimes to very high concentrations. As a result, radon is the largest source of exposure to people from naturally occurring radiation.

Relative risk: the ratio between the risks for disease in an irradiated population to the risk in an unexposed population. A relative risk of 1.1 indicates a 10% increase in cancer from radiation, compared with the "normal" incidence.

Rem (roentgen equivalent, man): a unit of equivalent dose. Not all radiation has the same biological effect, even for the same amount of absorbed dose. Rem relates the absorbed dose in human tissue to the effective biological damage of the radiation. It is determined by multiplying the number of rads by the quality factor, a number reflecting the potential damage caused by the particular type of radiation. The rem is the traditional unit of equivalent dose, but it is being replaced by the sievert (Sv), which is equal to 100 rem.

Roentgen (R): a unit of exposure to x-rays or gamma rays. One roentgen is the amount of gamma or x-rays needed to produce ions carrying 1 electrostatic unit of electrical charge in 1 cubic centimeter of dry air under standard conditions.

## S

Sensitivity: ability of an analytical method to detect small concentrations of radioactive material.

Shielding: the material between a radiation source and a potentially exposed person that reduces exposure.

Sievert (Sv): a unit used to derive a quantity called dose equivalent. This relates the absorbed dose in human tissue to the effective biological damage of the radiation. Not all radiation has the same biological effect, even for the same amount of absorbed dose. Dose equivalent is often expressed as millionths of a sievert, or micro-sieverts (µSv). One sievert is equivalent to 100 rem.

S.I. units: the Systeme Internationale (or International System) of units and measurements. This system of units officially came into being in October 1960 and has been adopted by nearly all countries, although the amount of actual usage varies considerably.

Somatic effects: effects of radiation that are limited to the exposed person, as distinguished from genetic effects, which may also affect subsequent generations. See also teratogenic effects.

Stable nucleus: the nucleus of an atom in which the forces among its particles are balanced. See also unstable nucleus.

Stochastic effect: effect that occurs on a random basis independent of the size of dose. The effect typically has no threshold and is based on probabilities, with the chances of seeing the effect increasing with dose. If it occurs, the severity of a stochastic effect is independent of the dose received. Cancer is a stochastic effect. S

Strontium (Sr): a silvery, soft metal that rapidly turns yellow in air. Sr-90 is one of the radioactive fission materials created within a nuclear reactor during its operation. Stronium-90 emits beta particles during radioactive decay.

Surface burst: a nuclear weapon explosion that is close enough to the ground for the radius of the fireball to vaporize surface material. Fallout from a surface burst contains very high levels of radioactivity.

## T

Tailings: waste rock from mining operations that contains concentrations of mineral ore that are too low to make typical extraction methods economical.

Thermonuclear device: a “hydrogen bomb.” A device with explosive energy that comes from fusion of small nuclei, as well as fission.

Teratogenic effect: birth defects that are not passed on to future generations, caused by exposure to a toxin as a fetus. See also genetic effects, somatic effects.

Thorium (Th): a naturally occurring radioactive metal found in small amounts in soil, rocks, water, plants, and animals. The most common isotopes of thorium are thorium-232 (Th-232), thorium-230 (Th-230), and thorium-238 (Th-238).

Transuranic: pertaining to elements with atomic numbers higher than uranium (92). For example, plutonium (Pu) and americium (Am) are transuranics.

Tritium: (chemical symbol H-3) a radioactive isotope of the element hydrogen (chemical symbol H).

## U

Unstable nucleus: a nucleus that contains an uneven number of protons and neutrons and seeks to reach equilibrium between them through radioactive decay (i.e., the nucleus of a radioactive atom). See also stable nucleus.

Uranium (U): a naturally occurring radioactive element whose principal isotopes are uranium-238 (U-238) and uranium-235 (U-235). Natural uranium is a hard, silvery-white, shiny metallic ore that contains a minute amount of uranium-234 (U-234).

Uranium mill tailings: naturally radioactive residue from the processing of uranium ore. Although the milling process recovers about 95% of the uranium, the residues, or tailings, contain several isotopes of naturally occurring radioactive material, including uranium (U), thorium (Th), radium (Ra), polonium (Po), and radon (Rn).

## W

Whole body count: the measure and analysis of the radiation being emitted from a person’s entire body, detected by a counter external to the body.

Whole body exposure: an exposure of the body to radiation, in which the entire body, rather than an isolated part, is irradiated by an external source.

## X

X-ray: electromagnetic radiation caused by deflection of electrons from their original paths, or inner orbital electrons that change their orbital levels around the atomic nucleus. X-rays, like gamma rays can travel long distances through air and most other materials. Like gamma rays, x-rays require more shielding to reduce their intensity than do beta or alpha particles. X-rays and gamma rays differ primarily in their origin: x-rays originate in the electronic shell; gamma rays originate in the nucleus. See also neutron.

 "Dawn of History" Studies have shown that at the end of the Ice Age in 11,000 BC, global temperatures increased 5 degrees, and during the height of the last Ice age, the Oceans were 300 feet lower than today.

U.S. OBSERVATORIES/PLANETARIUMS

 W.M. Keck Observatory                                            Downing Planetarium                Mauna Loa Summit, Hawaii                                                                       Los Angeles, CA

 LEAD   ( Pb - 82) -It's Poisoning effects- Is a Neurotoxin, too much in your system can cause irreparable damage to the brain and the central nervous system. It accumulates in the Bones and Blood. Levels measured in the US today; show that we have over 675 times more lead in our bodies than were present 100 years ago.

Our SUN (Star)
and its SOLAR SYSTEM

 `The diameter of the sun is 1,390,000 km. It is 93,000,000 miles from earth. It's mass it 1,000 greater than that of Earth.`` ` Our Sun takes 226 million years to circle the Milky Way Galaxy. It is approximately in the center (midway between the outside and the center) of the spiraling galaxy. The Sun is by far the largest object in the solar system in which we live. It contains more than 99.8% of the total mass of the Solar System. The Greeks called it Helios and the Romans called it Sol. The Sun is the closest star to Earth and is the center of our solar system. A giant, spinning ball of very hot gas, the Sun is fueled by nuclear fusion. Which propagates throughout the solar system at about 450 km/sec. The In addition to heat and light, the Sun also emits a low density stream of charged particles (mostly electrons and protons) known as the solar windsolar wind and the much higher energy particles ejected by solar flares can have dramatic effects on the Earth ranging from power line surges to radio interference to the beautiful aurora borealis. The Sun's magnetic field is very strong (by terrestrial standards) and very complicated. Its magnetosphere (also known as the heliosphere) extends well beyond Pluto. The Sun is about 4.5 billion years old; the Milky Way galaxy is at least 5 billion years older than that. Since its birth it has used up about half of the hydrogen in its core. It will continue to radiate "peacefully" for another 5 billion years or so (although its luminosity will approximately double in that time). But eventually it will run out of hydrogen fuel. There are many more smaller stars than larger ones; the Sun is in the top 10% by mass. The median size of stars in our galaxy is probably less than half the mass of the Sun.

Solar System:

The inner planets (those planets that orbit close to the sun) are quite different from the outer planets (those planets that orbit far from the sun).

In order from the Sun:

 PLANET DISTANCE FROM THE SUN DIAMETER OF PLANET MERCURY 27-41 Million miles 3,000 miles VENUS 65 Million Miles 7,200 Miles EARTH 93 Million Miles 7,600 Miles MARS 137 Million Miles 4,070 Miles JUPITER 466 Million Miles 85,788 Miles SATURN 856 Million Miles 72,000 Miles URANUS 1.08 Billion Miles 32,000 Miles NEPTUNE 2.80 Billion Miles 31,000 Miles

• The inner planets are: Mercury, Venus, Earth, and Mars. They are relatively small, composed mostly of rock, and have few or no moons.
• The outer planets include: Jupiter, Saturn, Uranus, Neptune, They are mostly huge, mostly gaseous, ringed, and have many moons.

The Moon:

Earths only Satellite is moving away from us at a rate of approximately 3.8 centimeters each year, also taking some of Earth's rotational energy,  It has been deduced, that when it formed, the Moon was about 14,000 miles (22,530 kilometers) from Earth. It's now more than 280,000 miles, or 450,000 kilometers away.

According to present theory, It is thought that the moon was once part of a planet that collided (It was not a head-on collision, but rather a glancing blow. The impact imparts what astronomers call angular momentum into the system. It sets Earth to spinning (although, the Earth could have already been spinning) on its axis and creates a Moon that would go round and round the host planet for billions of years, at least until it flies away, due to loss of gravity from Earth) with the forming earth, yet interestingly, if the Moon was carved out of the Earths growth phase ( the moon is thought to have been pieced together by the bits that got blown off the upper layers of Earth, as well as the outer portions of the object that hit Earth),  then it would have been around when Earth continued swallowing vast numbers of large asteroids. Some of these iron rich rocks would have hit the Moon, too, yet the iron is not on the moon?

Trivia

 Science: Ten per cent of the salt mined in the world each year is used to de-ice the roads in America. The air we breathe is 78% nitrogen, 21.5% oxygen, .5% argon and other gases. The largest gold nugget ever found weighed almost 173 lbs. The largest hailstone ever recorded was 17.5 inches in diameter - larger than a basketball. The most abundant metal in the Earth's crust is aluminum. Pumice is the only rock that floats in water. The three most common elements in the universe are 1. Hydrogen; 2. Helium; 3. Oxygen. Human Body: It takes 17 muscles to smile --- 43 to frown, do yourself a favor, SMILE, you won’t be as exhausted. Laughing lowers levels of stress hormones and strengthens the immune system. Six-year-olds laugh an average of 300 times a day. Adults only laugh 15 to 100 times a day. The average man manages to speak just over 2000 words in a day, on the other hand, on average a woman says close to 7,000 words a day. Some people never develop fingerprints at all. Two very rare genetic defects, known as Naegeli syndrome and dermatopathia pigmentosa reticularis, can leave carriers without any identifying ridges on their skin. The ashes of the average cremated person weigh approximately eight pounds. The average adult male human body contains enough: iron to make a 3 inch nail, sulfur to kill all fleas on an average dog, carbon to make 900 pencils, potassium to fire a toy cannon, fat to make 7 bars of soap, phosphorous to make 2,200 match heads, and water to fill a ten-gallon tank. The body's largest internal organ is the small intestine at an average length of 20 feet The feet account for one quarter of all the human bodies’ bones. Over 600 muscles make up 40% of the body's weight. The human brain is about 85% water. The largest human organ is the skin, with a surface area of about 25 square feet. The left lung is smaller than the right lung to make room for the heart. The most common blood type in the world is Type O. The rarest, Type A-H, The sound of a snore (up to 69 decibels) can be almost as loud as the noise of a pneumatic drill. Stratum corneum is the tough layer of skin. It covers the tips of fingers and the soles of feet. There are 45 miles of nerves in the skin of a human being. There are 60,000 miles of blood vessels in the human body. Though it makes up only 2 percent of our total body weight, the brain demands 20 percent of the body's oxygen and calories. Three-hundred-million cells die in the human body every minute. Women burn fat more slowly than men, by a rate of about 50 calories a day. Women's hearts beat faster than men's. Your stomach cells secrete hydrochloric acid, a corrosive compound used to treat metals in the industrial world. It can pickle steel, but mucous lining the stomach wall keeps this poisonous liquid safely in the digestive system. Misc: Forty-six percent of the world's water is in the Pacific Ocean The Arctic Ocean is the world's smallest & shallowest ocean. It is mostly covered by solid ice, ice flows, and icebergs The Atlantic Ocean is saltier than the Pacific Ocean The Mauna Loa volcano in Hawaii is the largest volcano on Earth. It rises more than 50,000 feet (9.5 miles or 15.2 kilometers) above its base, which sits under the surface of the sea. The world's tallest mountains, the Himalayas, are also the fastest growing. Their growth - about half an inch a year - is caused by the pressure exerted by two of Earth's continental plates (the Eurasian plate and the Indo-Australian plate) pushing against one another.

 TSUNAMI " Tsu\harbor nami/wave"  (the “T” is silent) (often incorrectly referred to as Tidal waves ) It usually takes an earthquake greater than 7.5 on the Richter scale to produce dangerous tsunami. Sometimes people use the words tidal wave and tsunami to mean the same thing. However, the two are not related. While tsunami refers to dangerous waves caused by underwater disturbances, tidal waves are simply the crest of tides as they travel around the Earth. Tsunamis have nothing to do with tides. A series of waves created when a body of water, such as an ocean, is rapidly displaced. Earthquakes (Tsunamis may be generated when an earthquake occurs causing the floor of the ocean to vertically displace the water column - one part "rises" while the other part "sinks"), mass movements above or below water, some volcanic eruptions and other underwater explosions, landslides and underwater earthquake at sea all have the potential to generate a tsunami. The effects of a tsunami are always devastating due to the immense volumes of water and energy involved. Since meteorites are small, they will not generate a tsunami, conversely, should an asteroid hit the oceans, the subsequent wave would be of extreme devastation. The first part of a tsunami to reach land is a trough (draw back) rather than a crest of the wave, the water along the shoreline may recede dramatically, exposing areas that are normally always submerged. This can serve as an advance warning of the approaching tsunami which will rush in faster than it is possible to run. If a person is in a coastal area where the sea suddenly draws back (many survivors report an accompanying sucking sound), their only real chance of survival is to run for high ground or seek the high floors of high rise buildings. A Tsunami looks like an endlessly onrushing tide which forces its way around and through any obstacle. Most of the damage is caused by the huge mass of water behind the initial wave front, as the height of the sea keeps rising fast and floods powerfully into the coastal area. The sheer weight of water is enough to pulverize objects in its path, often reducing buildings to their foundations and scouring exposed ground to the bedrock. Large objects such as ships and boulders can be carried several miles inland before the tsunami subsides. Tsunamis act very differently from typical surf swells; they are phenomena which move the entire depth of the ocean (often several kilometers deep) rather than just the surface, so they contain immense energy, propagate at high speeds and can travel great trans-oceanic distances with little overall energy loss. A tsunami can cause damage thousands of kilometers from its origin, so there may be several hours between its creation and its impact on a coast, arriving long after the seismic wave generated by the originating event arrives. Although the total or overall loss of energy is small, the total energy is spread over a larger and larger circumference as the wave travels.  A single tsunami event may involve a series of waves of varying heights; the set of waves is called a train. In open water, tsunamis have extremely long periods (the time for the next wave top to pass a point after the previous one), from minutes to hours, and long wavelengths of up to several hundred kilometers. This is very different from typical wind-generated swells on the ocean, which might have a period of about 10 seconds and a wavelength of 150 meters. The actual height of a tsunami wave in open water is often less than one meter. This is usually unnoticeable to people on ships. The energy of a tsunami passes through the entire water column to the sea bed, unlike surface waves, which typically reach only down to a depth of 10 m or so. The wave travels across open ocean at an average speed of 500 mph. As the wave approaches land, the sea shallows and the wave no longer travels as quickly, so it begins to 'pile-up'; the wave-front becomes steeper and taller, and there is less distance between crests. *While a person at the surface of deep water would probably not even notice the tsunami, the wave can increase to a height of six stories or more as it approaches the coastline and compresses. The steepening process is analogous to the cracking of a tapered whip. As a wave goes down the whip from handle to tip, the same energy is deposited in less and less material, which then moves more violently as it receives this energy. A wave becomes a 'shallow-water wave' when the ratio between the water depth and its wavelength gets very small, and since a tsunami has an extremely large wavelength (hundreds of kilometers), tsunamis act as a shallow-water wave even in deep oceanic water.  Tsunamis propagate outward from their source, so coasts in the "shadow" of affected land masses are usually fairly safe. However, tsunami waves can diffract around land masses. It's also not necessary that they are symmetrical, as a tsunami waves may be much stronger in one direction than another, depending on the nature of the source and the surrounding geography. *A tsunami has a much smaller amplitude (wave height) offshore, and a very long wavelength (often hundreds of kilometers long), which is why they generally pass unnoticed at sea, forming only a slight swell usually about 300 mm above the normal sea surface. A tsunami can occur at any state of the tide and even at low tide will still inundate coastal areas if the incoming waves surge high enough. Rogue Waves also known as freak waves, monster waves, extreme waves or hundred year waves, are relatively large and spontaneous ocean surface waves that are a threat even to large ships and ocean liners. In oceanography, they are more precisely defined as waves whose height is more than twice the significant wave height (SWH), It is common for mid-ocean storm waves to reach 7 meters (23 ft) in height, and in extreme conditions such waves can reach heights of 15 meters (49 ft). However, for centuries maritime stories are  told of the existence of vastly more massive waves — Monsters up to 35 meters (110 ft) in height (approximately the height of a 11-story building) — that could appear without warning in mid-ocean, against the prevailing current and wave direction, and often in perfectly clear weather. The areas of highest predictable risk appear to be where a strong current runs counter to the primary direction of travel of the waves; the area near Cape Agulhas off the southern tip of Africa is one such area. However, since this does not explain the existence of all waves that have been detected, several different mechanisms are likely, with localized variation. Suggested mechanisms for freak waves include the following: Diffractive focusing — According to this hypothesis, coast shape or seabed shape directs several small waves to meet in phase. Their crest heights combine to create a freak wave. Focusing by currents — Storm forced waves are driven into an opposing current. This results in shortening of wavelength, causing shoaling (i.e., increase in wave height), and oncoming wave trains to compress together into a rogue wave. Nonlinear effects — it seems possible to have a rogue wave occur by natural, nonlinear processes from a random background of smaller waves. In such a case, it is hypothesized, an unusual, unstable wave type may form which 'sucks' energy from other waves, growing to a near-vertical monster itself, before becoming too unstable and collapsing shortly after. One simple model for this is a wave equation known as the nonlinear Schrödinger equation (NLS), in which a normal and perfectly accountable (by the standard linear model) wave begins to 'soak' energy from the waves immediately fore and aft, reducing them to minor ripples compared to other waves. Such a monster, and the abyssal trough commonly seen before and after it, may last only for some minutes before either breaking, or reducing in size again. The NLS is only valid in deep water conditions, and in shallow water an alternative such as the Boussinesq equation is used. Normal part of the wave spectrum — Rogue waves are not freaks at all but are part of normal wave generation process, albeit a rare extremity. Wind waves — while it is unlikely that wind alone can generate a rogue wave, its effect combined with other mechanisms may provide a fuller explanation of freak wave phenomena. As wind blows over the ocean, energy is transferred to the sea surface. Phillip and Miles provide some insight into the problem, though it still remains a tricky one. There are three categories of freak waves: "Walls of water" travelling up to 10 km (6.2 mi) through the ocean "Three Sisters", groups of three waves Single, giant storm waves, building up to fourfold the storm's waves height and collapsing after some seconds

ULTRASOUND

An imaging ultrasound is a simple, safe and routine procedure using very high frequency (ultrasonic) sound waves to "look inside" the body. Ultrasound imaging, also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body.

Ultrasound exams do not use ionizing radiation (x-ray). Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels

Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats the sound wave data into 3-D images. Four-dimensional (4-D) ultrasound is 3-D ultrasound in motion.

### Benefits

• Ultrasound scanning is noninvasive (no needles or injections) and is usually painless.
• Ultrasound is widely available, easy-to-use and less expensive than other imaging methods.
• Ultrasound imaging uses no ionizing radiation.
• Ultrasound scanning gives a clear picture of soft tissues that do not show up well on x-ray images.
• Ultrasound causes no health problems and may be repeated as often as is necessary if medically indicated.
• Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn infants.
• Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and needle aspiration of fluid in joints or elsewhere.

### Limitations:

Ultrasound is not an ideal imaging technique for the bowel. Barium exams and CT scanning are the methods of choice for bowel-related problems.

Ultrasound waves do not pass through air; therefore an evaluation of the stomach, small intestine and large intestine may be limited. Intestinal gas may also prevent visualization of deeper structures such as the pancreas and aorta. Patients who are obese are more difficult to image because tissue attenuates (weakens) the sound waves as they pass deeper into the body.

Ultrasound has difficulty penetrating bone and therefore can only see the outer surface of bony structures and not what lies within. For visualizing internal structure of bones or certain joints, other imaging modalities such as MRI are typically used.

### Risks:

There are no known harmful effects.

Doppler ultrasound is a special ultrasound technique that evaluates blood as it flows through a blood vessel, including the body's major arteries and veins in the abdomen, arms, legs and neck.

There are three types of Doppler ultrasound:

• Color Doppler uses a computer to convert Doppler measurements into an array of colors to visualize the speed and direction of blood flow through a blood vessel.
• Power Doppler is a newer technique that is more sensitive than color Doppler and capable of providing greater detail of blood flow, especially in vessels that are located inside organs. Power Doppler, however, does not help the radiologist determine the direction of flow, which may be important in some situations.
• Spectral Doppler. Instead of displaying Doppler measurements visually, Spectral Doppler displays blood flow measurements graphically, in terms of the distance traveled per unit of time.

Ultrasound examinations can help to diagnose a variety of conditions and to assess organ damage following illness.

Ultrasound is used to help physicians diagnose symptoms such as:

• pain
• swelling
• infection

Ultrasound is a useful way of examining many of the body's internal organs, including but not limited to the:

• heart and blood vessels, including the abdominal aorta and its major branches
• liver
• spleen
• pancreas
• kidneys
• uterus, ovaries, and unborn child (fetus) in pregnant patients
• eyes
• thyroid and parathyroid glands
• scrotum (testicles)

Ultrasound is also used to:

• guide procedures such as needle biopsies, in which needles are used to extract sample cells from an abnormal area for laboratory testing.
• image the breasts and to guide biopsy of breast cancer
• diagnose a variety of heart conditions and to assess damage after a heart attack or other illness.

Doppler ultrasound images can help the physician to see and evaluate:

• blockages to blood flow (such as clots)
• narrowing of vessels (which may be caused by plaque)
• tumors and congenital malformation

VOLCANOES
Named after Vulcan, son of Jupiter and blacksmith to the Roman gods

Over 80% of the earth’s surface is of volcanic in origin. The sea floor and some mountains were formed by numerous volcanic eruptions. Gaseous emissions from volcano formed the earth's atmosphere. There are more than 500 active volcanoes in the world. In excess of half of these volcanoes are part of the "Ring of Fire," a region that encircles the Pacific Ocean.

COMPOSITION of lava is that of basaltic or granitic in composition. Granitic lava contains high amounts of silica and is extremely thick. Because it is thick, it gets trapped in the vents and builds up pressure. This pressure is released in violent explosions. Basaltic lava produces quiet, oozy eruptions that slide down the side of the volcano. Balsaltic lava contains less silica and isn't as thick so it flows more easily.

GASES: The major gases which are associated with magma are carbon dioxide and water vapor. They can make-up a much as 14% of the magma. These gases increase the violence of the eruption.

Features of a Volcano:

A volcanic "vent" is where volcanic material is emitted. All volcanoes contain a central vent underlying the summit crater of the volcano. The volcano's cone-shaped structure, or edifice, is built by the more-or-less symmetrical accumulation of lava and/or pyroclastic material around this central vent system. The central vent is connected at depth to a magma chamber, which is the main storage area for the eruptive material. Because volcano flanks are inherently unstable, they often contain fractures that descend downward toward the central vent, or toward a shallow-level magma chamber. Such fractures may occasionally tap the magma source and act as conduits for flank eruptions along the sides of the volcanic edifice. These eruptions can generate cone-shaped accumulations of volcanic material, called parasitic cones. Fractures can also act as conduits for escaping volcanic gases, which are released at the surface through vent openings called fumaroles.

Fumarole: The yellow color around this fumarole comes from sulfur crystals derived from the cooling of sulfur vapor escaping from the fumarole opening.  Very prominent in Hawaii in the Kilauea Volcano and the surrounding areas of the caldera at Volcanoes National Park.

A volcanic "vent" is where volcanic material is emitted. All volcanoes contain a central vent underlying the summit crater of the volcano. The volcano's cone-shaped structure, or edifice, is built by the more-or-less symmetrical accumulation of lava and/or pyroclastic material around this central vent system. The central vent is connected at depth to a magma chamber, which is the main storage area for the eruptive material. Because volcano flanks are inherently unstable, they often contain fractures that descend downward toward the central vent, or toward a shallow-level magma chamber. Such fractures may occasionally tap the magma source and act as conduits for flank eruptions along the sides of the volcanic edifice. These eruptions can generate cone-shaped accumulations of volcanic material, called parasitic cones. Fractures can also act as conduits for escaping volcanic gases, which are released at the surface through vent openings called fumaroles.

Summit Crater:

The crater is situated atop the mountain formed from the erupted volcanic deposits such as lava flows and tephra. Volcanoes that terminate in such a summit crater are usually of a conical form. Other volcanic craters may be found on the flanks of volcanoes, and these are commonly referred to as flank craters. Some volcanic craters may fill either fully or partially with rain and/or melted snow, forming a crater lake.

Parasitic Cones:

The growth of parasitic cones on the flanks of large composite volcanoes is a sign of old age. Not uncommonly, these cones develop at successively lower levels as the volcanoes approach extinct. Usually, they are made up of more basic and more siliceous differentiates. Parasites may be concentrated along lines or belts that reflect structural trends in the subvolcanic basement, or in a crudely concentric arrangement. The concentric rings may reflect cone-sheets or ring dikes at depth. A crudely radial arrangement of parasitic cones and domes is much more common. The number of parasitic cones on most large composite cones is seldom more than ten or a dozen.

There are nearly 100 parasitic scoria cones on the flanks of Mauna Kea volcano, Hawaii. Mt. Shasta in California,  Mt. Baker in Washington State, the Galapagos Islands and many others worldwide share space with Parasitic Cones.

Three main Types of Volcanoes

Scoria Cone: Also know as Cinder Cones, are the most common type of volcano
Eruption type is Strombolian. (These vary from small volcanic blasts, to kilometer-high eruptive columns. However, true strombolian activity is characterized by short-lived, explosive outbursts of thick lava ejected a few tens or hundreds of meters into the air. Although Strombolian eruptions are much noisier than Hawaiian eruptions, they are not more dangerous).
They are shaped with straight sides with steep slopes and a large summit crater.
Basic material composition of Basalt tephra, and occasionally andesitic.

Shield Volcano:
Eruption type is Hawaiian ( Although, Kilauea can provide for some spectacular fire fountains) Shaped with very gentle slopes: convex upward.

Their material composition is a Basalt lava flow Shield volcanoes are the largest volcanoes on Earth that actually look like volcanoes (i.e. not counting flood basalt flows). The Hawaiian shield volcanoes are the most famous examples. Shield volcanoes are almost exclusively basalt, a type of lava that is very fluid when erupted. For this reason these volcanoes are not steep. Eruptions at shield volcanoes are only explosive if water somehow gets into the vent, otherwise they are characterized by low-explosivity fountaining that forms cinder cones and spatter cones at the vent, however, 90% of the volcano is lava rather than pyroclastic material. Shield volcanoes are the result of high magma supply rates; the lava is hot and little-changed since the time it was generated. Shield volcanoes are the common product of hotspot volcanism but they can also be found along subduction-related volcanic arcs or all by themselves.

Stratovolcanoes: (best known was Pompaii, located at the base of Mt. Vesuvius)
Also know as Composites (cones). They are the most deadly of volcano types. The lower slopes are gentle, but they rise steeply near the summit. The summit typically contains a surprisingly small crater.
Eruption type is Plinian (Plinian is named after Pliny the Elder", a much respected naturalist and Admiral in the Roman navy who died during the eruption) eruptions generate large eruptive columns that are powered upward partly by the thrust of expanding gases, and by convective forces with exit velocities of several hundred meters per second. They are Very Explosive with powerful convecting plumes of ash ascending up to 45 kilometers into the stratosphere. These spectacularly explosive eruptions are associated with volatile-rich dacitic to rhyolitic lava, which typically erupts from stratovolcanoes. The duration these eruptions is highly variable, from hours to days. The longest eruptions appear to be associated with the most felsic volcanoes. Although Plinian eruptions typically involve felsic magma, they can occasionally occur in fundamentally basaltic volcanoes where the magma chambers become differentiated and zoned to create a siliceous top.

Their material composition is highly variable: alternating basaltic to rhyolitic lavas and tephra with an overall andesite composition.

Vulcanian eruptions
initially occur as a series of discrete, canon-like explosions that are short-lived, lasting for only minutes to a few hours, often with high-velocity ejections of bombs and blocks. Once the volcano "clears its throat," however, the subsequent eruptions can be relatively quiet and sustained. Vulcanian eruptions are more explosive than Strombolian eruptions with eruptive columns commonly between 5 and 10 km heigh. The volume of tephra produced is relatively small (less than one cubic kilometer), but dispersed over a moderately wide area

Lava and tephra can erupt from vents other than these three main volcano types. A
fissure eruption, for example, can generate huge volumes of basalt lava; however, this type of eruption is not associated with the construction of a volcanic edifice around a single central vent system. Although point-source eruptions can generate such features as spatter cones and hornitos, these volcanic edifices are typically small, localized, and/or associated with rootless eruptions (i.e., eruptions above the surface of an active lavaflow, unconnected to an overlying magma chamber) . Vent types related to hydrovolcanic processes generate unique volcanic structures.

Volcanic Explosivity Index:

It is common to find traditional names from classic eruptions to describe other eruptions and volcano forms: Hawaiian, Strombolian, Vulcanian, Surtseyan and Vesuvian (Plinian), for example. These names are widely used in volcanological literature.

 0 Non-Explosive (Hawaiian) Plume: 100 m/Volume: 1 Gentle (Hawaiian - Strombolian) Plume: 100 - 1000 m/Volume: 2 Explosive (Strombolian - Vulcanian) Plume: 1 - 5 km/Volume: 3 Severe (Vulcanian) Plume: 3 - 15 km/Volume: 4 Cataclysmic (Vulcanian - Plinian) Plume: 10 - 25 km/Volume:

Massive fissure (Fissure-Fed Basalt Provinces) eruptions in the geological past have generated extraordinarily voluminous lava flows that form large continental flood basalt provinces. Individual provinces can cover hundreds of square kilometers, with average thicknesses of one kilometer. These flood-basalt ( the Imnaha Basalts and then the later *Columbia River Flood Basalts (Grande Ronde Basalts), Deccan flood basalts, which erupted about 65 million years ago in western India, and the Siberian flood basalts, which erupted about 245 million years ago in northern Siberia. ) eruptions are rare in the geologic record. They generate huge volumes of basalt over a very short time intervals, typically in only 1-2 million years.

Flood-basalt eruptions are often intimately related to rifting or to stretching of the earth's crust above a region of hot mantle. This process can generate huge volumes of magma that rises through fractures to produce massive fissure eruptions on the surface. Basalt filled fissures on the Columbia Plateau, are currently exposed as dikes. About 14 million years ago, 700 cubic kilometers of basalt erupted from a single such fissure on the Columbia Plateau (Grande Ronde) to form the Roza flow. The Roza flow is typical in volume to many of the larger flows in the Columbia River Basalt Province. The largest of the Columbia River Basalt flows travelled up to 500 kilometers west of their source fissures. The flow created flow ended at the present site of the Columbia River in Central Washingtion state, the westernmost extent stopping on the outskirts of Portland Oregon.  The Tri-State Columbia plateau covers corners of Washington, Oregon and Idaho. The deepest gorge (deeper than the Grand Canyon) in the United States is disected by the Snake river in Washington state, providing for an excellent example of the depth provided by  Flood basalt flow.

#### ANDESITIC LAVA

The rock occurs as lava flows and dikes in regions where the plates of the earth's crust collide with one another. Andesitic lava has a composition that falls in between that of basaltic lava and that of rhyolitic lava and is classified as an intermediate rock. Andesitic lava flows more readily than rhyolitic lava, but not as easily as basaltic lava. Eruptions are characterized by a mixture of explosive activity and lava flows. Such eruptions form composite volcanoes, built up of alternating lava flows and pyroclastic deposits. Whereas basalt forms a'a and pahoehoe surface forms, andesite generally produces blocky lava. Here, the surface contains smooth-sided, angular fragments (blocks) that are not as splintery or vesicular as a'a lava fragments. The blocky nature of these flows is attributed to the higher viscosity of andesite.

BASALTIC LAVA

Pahoehoe Lava -- Surfaces are smooth, billowy, or ropy.
A'a lava -- Surfaces are fragmented, rough, and spiny, with a "cindery" appearance

Basaltic flows are the hottest, erupting at temperatures of 1,832–2,192°F (1,000–1,200°C). Basaltic lavas are high in calcium, magnesium, and iron, and low in silica, sodium, and potassium. Based on its composition, basalt is known as a mafic rock. The high temperature and low silica content allow basaltic lavas to flow readily and travel far. The Hawaiian Islands were built up from the seafloor from successive basaltic lava flows, forming large shield volcanoes. When basaltic lava erupts onto relatively flat land, flows known as flood basalts may spread out, with successive flows being piled on top of one another. The Columbia Plateau in Oregon and Washington were formed from such eruptions. Viscosity differences within basaltic lavas result in two distinct flow types, characterized by their surface forms. Pahoehoe (pah-hoy-hoy), formed from less viscous lava, is named for the Hawaiian word for ropy. When solidified, the surface of a pahoehoe flow has a smooth texture that looks like coiled rope, which forms as the outer layer of the lava cools, then is dragged and folded as the flow continues to move beneath the surface. More viscous basalt flows give rise to aa (ah-ah) lava, characterized by blocky clumps. Aa flows move more slowly than do pahoehoe flows, allowing a thick surface layer to cool as the flow creeps forward. As the flow continues to move, the surface layer is broken into jagged pieces. Pahoehoe is common near the source of a basaltic flow, where the lava is hottest, and aa is normally found farther from the source, where the lava has cooled off significantly. Another unique feature of basaltic lava is the formation of pillow lavas. Mounds of ellipse shaped pillows form when basaltic lava is erupted under water. As lava is extruded, the water quickly chills the outer layer. Molten lava beneath the surface eventually breaks through the skin and the process is repeated, resulting in a pile of lava pillows. Pillow lava deposits found on land indicate that the region was once under water. Basaltic lava flows erupt primarily from shield volcanoes, fissure systems, scoria cones, and spatter cones.

RHYOLITIC LAVA

Rhyolitic lavas are high in potassium, sodium, and silica, and low in calcium, magnesium, and iron. Rhyolite is a classified as a felsic rock. It is chemically identical to granite, and is composed essentially of feldspar and quartz. Of the dark minerals that occur in some specimens of rhyolite, dark brown biotite is the most common. Augite and hornblende also occur in some rhyolites. Some specimens of rhyolite have a striated or streaked appearance and others are uniform in appearance. In addition to its low eruptive temperature (1,472–1,832°F, or 800–1,000°C), results in highly viscous lava that can just barely flow. Such lavas usually produce a volcanic dome that eventually is destroyed in a massive explosion as the viscous lava tries to escape. This type of flow is seen in Lassen Peak in California.

TEPHRA
The words "tephra" and "pyroclast" both derive from Greek. Tephra means "ash". Pyro means "fire" and klastos means "broken"; thus pyroclasts carry the connotation of "broken by fire".

Tephra is air-fall material produced by a volcanic eruption regardless of composition or fragment size.[1] Tephra is typically rhyolitic in composition, as most explosive volcanoes are the product of the more viscous felsic or high silica magmas.

Volcanologists also refer to airborne fragments as pyroclasts (also referred to as clasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff. The distribution of tephra following an eruption usually involves the largest boulders falling to the ground quickest and therefore closest to the vent, while smaller fragments travel further—ash can often travel for thousands of miles, even circumglobal, as it can stay in the stratosphere for several weeks. When large amounts of tephra accumulate in the atmosphere from massive volcanic eruptions (or from a multitude of smaller eruptions occurring simultaneously), they can reflect light and heat from the sun back through the atmosphere, in some cases causing the temperature to drop, resulting in a climate change: "volcanic winter". Tephra mixed in with precipitation can also be acidic and cause acid rain and snowfall.

Tephra fragments are classified by size:

• Ash - particles less than 2 mm in diameter
• Lapilli or volcanic cinders - between 2 and 64 mm in diameter
• Volcanic bombs or volcanic blocks - greater than 64 mm in diameter
•

CALDERAS

A caldera is a large, usually circular depression at the summit of a volcano formed when magma is withdrawn or erupted from a shallow underground magma reservoir. After a huge ejection of lava there may be no magma left in the chamber to fill the conduit and crater. When this happens there is a hollow space under the summit of the mountain where the magma used to be. The top of the mountain then collapses creating a caldera. Calderas are different from craters, which are smaller, circular depressions created primarily by explosive excavation of rock during eruptions.

 This image is in the public domain because it contains materials that originally came from the United States Geological Survey, an agency of the United States Department of Interior. For more information, see the official USGS copyright policy

Three variations in form for calderas:

• Crater-Lake type calderas associated with the collapse of stratovolcanoes
• Basaltic calderas associated with the summit collapse of shield volcanoes
• Resurgent calderas which lack an association with a single centralized vent

Noted Calderas:

Aniakchak Caldera, AK/US
*Yellowstone, WY/US
Krakatau, Indonesia
Long Valley, CA/US
Newberry Caldera, OR/US
Medicine Lake caldera. CA/US
Valles caldera , NM/US
Kilauea HI/US
Moku'aweoweo, (the caldera of Mauna Loa), HI/ US
Erta Al, Ethopia
Battleground Lake, WA/US
Crater Lake " Mt. Mazama" OR/US
Galapagos Islands
Cerro Galan, Argentina
Toba Caldera, Sumatra
Valles Caldera, Mexico
Tanzania, Africa
southern Kyushu, Japan

 *600,000 years ago a huge eruption filled the area with lava flows. After the huge eruption there was a void under the top of the volcano. The weight of the volcano caused the top to come crashing down forming the large caldera today known as Yellowstone National park. Yellowstone sits atop a continental hot spot. As the North American plate moves steadily westward the permanent hot spot affects different areas of the continent. (The Hawaiian islands are a very good example of this movement) Volcanic activity can be traced across the United States as the plate has moved across this hot spot. This caldera is one of the largest calderas in the world. It is over 65 miles across.

Resurgent Calderas:

Begin when gas-rich magma collects near the roof of a magma chamber bulging under older volcanic rocks. After an eruption begins and collapse is initiated, ring shaped fractures  begin growing out of the chamber and burst to the surface, creating a vent for steam and gas. Decompressing gases and jets of pumice and ash follow at high speeds into the atmosphere. The upper part of the magma chamber froths, expands and flows up the vent. The velocity decreases as magma from the deeper parts of the chamber begin to flow out and the rocks overlying the magma begin to collapse along the fractures into the now emptied chamber. Pyroclastic flows continue as the initial burst of ash and deeper parts of magma flow across the surface covering the caldera and surrounding geographic area. The magma chamber is then depleted in gases and minor volcanic activity can persist along the ring fracture for as much as a million years. The crater is then mostly filled with volcanic ash and pumice and is quickly occupied by a crater lake. This flat-floored crater doesn't stay this way for long; the magma, now depleted in gases, continues to slowly rise. The crater floor is pushed up, forming a giant "blister".  Large resurgent calderas are among the most destructive natural catastrophes on Earth. Krakatoa (Indonesia) and Taal (Philippines) are two examples of cataclysmic events. Other resurgent caldera examples are Long Valley caldera in California, Yellowstone caldera in Wyoming, and Toba caldera in northern Sumatra.

 Founded in December 1904 by George Ellery Hale as one of the original scientific enterprises of the Carnegie Institution of Washington, Mt. Wilson Observatory is completing its first century as one of the world's premier astronomical observatories. During the first half of the twentieth century Mt. Wilson was successively home to the world's two largest telescopes as well as the most powerful facilities in existence for studying the sun. The 60-inch and 100-inch night-time telescopes and the 60-ft and 150-ft solar tower telescopes in the hands of the brilliant scientists who used them revolutionized astronomy through such discoveries as: realizing that the Sun is not at the center of the Milky Way galaxy proof that countless galaxies exist in addition to the Milky Way the existence of the magnetic field of the sun and its key role in solar activity the recession of the galaxies indicating the Big Bang origin of the Universe the existence of populations of stars of various ages in our galaxy

 THE WORLD WIDE WEB was invented at CERN in 1989 by Tim Berners-Lee CERN - The world's largest particle physics laboratory "Overwelmingly Awesome Science" Consider that the subject particle in this LHC is traveling 47,000 laps around a 4 mile tunnel in "1 second". Located in Genève, Switzerland

X-RAY

1 mrem per year is a negligible dose of radiation, and 25 mrem per year from a single source is the upper limit of safe radiation exposure. Too much radiation at one body site can cause skin conditions resembling severe burns or local cancers. Widely distributed over the body so that it penetrates much of the blood-forming marrow, excessive radiation can cause leukemia.

It would take approximately 300 000 X-rays in one day to kill body cells (see below: Deterministic radiation damage). Nonetheless, diagnostic X-rays should be used as sparingly as possible.

X-rays are also referred to as radiographs or roentgenograms (after W.C. Roentgen). Conventional x-ray imaging has evolved over the past 100 years, but the basic principal is still the same as in 1895.  An x-ray source is turned on and x-rays are radiated through the body part of interest and onto a film cassette positioned under or behind the body part. A special phosphor coating inside the cassette glows and exposes the film. The resulting film is then developed much like a regular photograph. It is the special energy and wavelength of the x-rays which allow them to pass through the body part and create the image of the internal structures. One of the earliest applications of X-rays was in medicine, where they were used for both diagnosis and Therapy.  X-rays are still widely used in this field. They penetrate soft tissues but are stopped by bones, which absorb them. Thus if a photographic plate that is sensitive to X-rays is placed behind a part of the body and an X-ray source is placed in front, X-ray exposure will result in a picture of the internal bones and organs. When the plate, or radiograph, is developed, a negative image is produced: bones and dense tissues show up as light or white regions, while tissues that are easily penetrated by X-rays appear dark. Although bones are the most opaque structures in the body, there are many dense tissues, such as cancer tumors, that can also show up unusually light in radiographs X-rays are produced whenever high-energy electrons suddenly give up energy ... X-ray machines which produce these rays accelerate electrons towards a metal target. The electrons rapidly slow down when they collide with atoms in the target, and part of their energy is changed into X-rays.

X-rays are a type of electromagnetic radiation, as are radio waves and visible light. Medical X-rays have a wavelength about 1/20,000 that of light, or energy per photon of about 20,000 times that of a visible photon.

X-radiation is produced by X-ray tubes in which energetic electrons smash into a tungsten target (sometimes it is molybdenum or other material). When the electrons are stopped by the target, they very occasionally emit an X-ray photon.

X-rays are useful to medicine because they can pass right through the body to cast shadow pictures. They best portray large differences in atomic number (e.g., bone versus soft tissue) and differences in density (air versus anything else). They don’t do as well at distinguishing soft tissues from each other except for specialized exams like mammography for breast cancer detection. Often special “contrast agents” are injected or swallowed, such as iodine compounds to visualize blood vessels, or barium for the stomach.

X-ray imaging systems have higher spatial resolution than MRI or ultrasound, and are the method of choice for assessing fractures. X-ray images can be acquired and displayed in real time on a TV monitor which makes them very useful for following motion such as swallowing or of blood flow through an organ.

The principals of fluoroscopy are much the same as with film x-ray (called radiography) described above. However, fluoroscopic imaging yields a moving x-ray picture or movie. The original "fluoroscopes" consisted of an x-ray system and a fluorescent screen which registered the x-rays and emitted glowing light. The doctor could watch the fluorescent screen and see a dynamic (moving) image of the patient's body (for example the beating heart). Fluoroscopic technology improved greatly with the addition of television cameras and fluoroscopic "image intensifiers".

One of the earliest applications of X rays was in medicine, where they were used for both diagnosis and Therapy. Today X rays are still most widely used in this field. They penetrate soft tissues but are stopped by bones, which absorb them. Thus if a photographic plate that is sensitive to X rays is placed behind a part of the body and an X-ray source is placed in front, X-ray exposure will result in a picture of the internal bones and organs. When the plate, or radiograph, is developed, a negative image is produced: bones and dense tissues show up as light or white regions, while tissues that are easily penetrated by X rays appear dark. Although bones are the most opaque structures in the body, there are many dense tissues, such as cancer tumors, that can also show up unusually light in radiographs.

Of note regarding safety:

X-rays are ionizing, hazardous radiation. Acute high exposure causes dose-related damage to all tissues and may lead to burns, necrosis (death of cells), or DNA damage resulting in cancer and dysfunctional proteins. X-rays are known to exert profound adverse effects on the developing embryo (leading to birth defects) and on reproductive function in men and women to name but a few. The consequences of long-term, low exposure to ionizing radiation such as X-rays are not well understood, however numerous medical investigations show their harmful effects.

Backscatter X-ray is a newer imaging system which detects the radiation which comes back from the target. It has potential applications in almost every situation in which non-destructive examination is required, but only one side is available for examination.

The resolution of the resulting images is quite high. Some backscatter X-ray scanners are able to penetrate up to 30cm (~12") of solid steel. As such, the technology is in use to search containers and trucks much more quickly than performing a physical search, and potentially allow a larger percentage of shipping to be checked for smuggled items or weapons. According to Farren Technology, the technology exists to scan areas as far as 50 meters away from the device, producing 3D images of people's bodies and the weapons they might be hiding. In comparison to x-rays from medical applications, the backscattered x-rays are considered high energy and usually scatter instead of penetrate materials. A "high energy x-ray beam" moves rapidly over the person's form and a high resolution image of the person's body is constructed when the scattered x-ray "from a known position" is detected.

## MILLIREMS

X-Rays are something many people will want to avoid unless absolutely necessary. X-Rays are not the best diagnostic tool for all things.

How much radiation does a person receive in an average dental X-Ray? for a comparison, measured in millirems; the standard measure of radiation absorption by human cells:

Flight from Los Angeles to Paris (cosmic rays) 4.8 Millirems.

Chest X Ray (l film) 6-30 Millirems.

Contamination 1/2 mile from Three Mile Island during nuclear accident 83.0 Millirems.

Apollo X astronauts on moon flight (cosmic rays) 480.0 Millirems.

Dental X-ray (whole mouth) 25-36 Millirems.

On-site dose at Three Mile Island accident 1100.0 Millirems.

Breast mammography (1 film) 1500.0 Millirems.

Current N.A.S. yearly occupational exposure accumulative limit is 5000.0 Millirems.

 Legal:  Lyntren Communications, Inc. provides no compensation to contributors.  Lyntren reserves the right to refuse any and all submissions. Lyntren Communications does not return any submissions or entries. The information contained in QuickTip.com is "AS IS", "WITH ALL FAULTS". User assumes all risk of use, damage, or injury. You agree that we have no liability for any damages whatsoever. We are not liable for any consequential, incidental, indirect, or special damages. You indemnify us for claims caused by you.

We wish to thank all of those who have generously provided us with information, support and encouragement.
Special thanks to wikipedia.org- PLEASE DONATE TO THEM.