What Is Teflon®

Teflon® is a brand of polytetrafluoroethylene (PTFE), a solid polymer that is considered to be one of the world's most slippery substances. Accidentally invented in 1938 a laboratory in Deepwater, New Jersey, in the United States, Teflon® has applications in a wide range of areas, including household goods, the aerospace industry, electronics and industrial processes. Teflon® is produced by E.I. du Pont de Nemours and Company, also known as DuPont.

History

PTFE is a fluorocarbon, a compound made up of carbon and fluorine, and it has the molecular formula (C₂F₄)n. A chemist named Roy Plunkett accidentally invented PTFE while trying to create a new chlorofluorocarbon in a New Jersey laboratory operated by Kinetic Chemicals Inc., a company that was co-founded by DuPont and General Motors. Plunkett discovered that the white, wax-like substance that was created during one of his experiments was extremely slippery and water-resistant. The substance was patented in 1941, and the Teflon® trademark was registered in 1945.

Qualities

Teflon® has a coefficient of friction against polished steel of 0.05 to 0.1, which is one of the lowest for any solid that has been measured. This makes it suitable for use in applications that require reduced friction between two solids, such as gears or sliding parts. It also is hydrophobic, which means that it repels water instead of getting wet. Among PTFE's other qualities that make it beneficial for many uses are its high melting point and its electrical insulating properties.

Uses

In the 21st century, in addition to its widespread use in manufacturing and industry, PTFE is used on all sorts of everyday items. Many people are familiar with non-stick cooking pots and pans that have been coated with Teflon®. Automobile wiper blades also are commonly coated with PTFE, which helps keep the blades from squeaking as they pass back and forth across the windshield. PTFE also is used as a carpet or fabric protector because it repels liquids, allowing spills to be wiped up without leaving a stain. It has been used on all-weather clothing, to coat eyeglass lenses, as a fingernail protector and even in a line of haircare products.

Safety

There has been some concern about the safety of PTFE, especially in cookware. In the U.S., the Environmental Protection Agency (EPA) and Food and Drug Administration (FDA) have stated that the use of this coating on cookware and other items commonly used by people does not pose a concern. DuPont has said that Teflon® coatings do begin to deteriorate at or above 500° Fahrenheit (260° Celsius), a temperature higher than that at which most foods are cooked. Teflon®-coated pans are not recommended for cooking techniques that require very high temperatures, such as broiling.

What is an Embryo

An embryo is an organism in the early stages of development which cannot survive on its own. The precise definition of an embryo varies; in humans, for example, a fertilized egg may be considered an embryo until around the eighth week of pregnancy, at which point it is termed a fetus. The study of embryos is known as embryology, and it makes up part of a larger branch of science which is interested in reproduction and development.

The term “embryo” is only used to refer to eukaryote organisms, otherwise known as multicellur organisms. Typically, people use the term specifically to refer to diploid eukaryotes, meaning that the embryo has a complete set of genetic material from two donors. This genetic material takes the form of haploid sperm and eggs; a haploid cell only contains half a set of chromosomes, meaning that it cannot develop into anything unless it is combined with another haploid cell. As an embryo matures, it starts to turn into a recognizable form, at which point people may start referring to it as a fetus, especially in humans.

The formation of an embryo starts at fertilization. When eggs and sperm meet, they form what is known as a zygote. A zygote is a single diploid cell, created through the merging of two haploid cells. After fertilization, the zygote starts to divide, laying the groundwork for the mature organism which will eventually be born, hatched, or grown. When division begins, a zygote turns into an embryo.

Embryos cannot survive independently because they lack the tissues, body structure, organs, and so forth needed to do so. The parent of an embryo must feed it and watch out for it until it reaches viability. In mammals, this is accomplished by incubating the embryo inside the body and nourishing it with nutrients from the parents. Plants and egg laying animals provide the embryo with a rich layer of nutrients encased in a hard shell which will protect it until it is ready to be born.

The status of embryos is rather complex. Some people feel that an embryo is a life form, since it represents the potential of a living organism. Others do not regard embryos as lives, since they cannot survive on their own, and in the early stages they do not resemble anything familiar. This debate has led to conflict in some parts of the world, especially when it comes to human embryos and the choice to terminate a pregnancy.

What Is Rust

Rust is another name for iron oxide, which occurs when iron or an alloy that contains iron, like steel, is exposed to oxygen and moisture for a long period of time. Over time, the oxygen combines with the metal at an atomic level, forming a new compound called an oxide and weakening the bonds of the metal itself. Although some people refer to rust generally as "oxidation," that term is much more general; although rust forms when iron undergoes oxidation, not all oxidation forms rust. Only iron or alloys that contain iron can rust, but other metals can corrode in similar ways.

The main catalyst for the rusting process is water. Iron or steel structures might appear to be solid, but water molecules can penetrate the microscopic pits and cracks in any exposed metal. The hydrogen atoms present in water molecules can combine with other elements to form acids, which will eventually cause more metal to be exposed. 

If sodium is present, as is the case with saltwater, the corrosion is likely to occur more quickly. Meanwhile, the oxygen atoms combine with metallic atoms to form the destructive oxide compound. As the atoms combine, they weaken the metal, making the structure brittle and crumbly.

Some pieces of iron or steel are thick enough to maintain their integrity even if iron oxide forms on the surface. The thinner the metal, the better the chance that rusting will occur. Placing a steel wool pad in water and exposing it to air will cause rusting to begin almost immediately because the steel filaments are so thin. Eventually, the individual iron bonds will be destroyed, and the entire pad will disintegrate. 

Rust formation cannot be stopped easily, but metals can be treated to resist the most damaging effects. Some are protected by water-resistant paints, preventative coatings or other chemical barriers, such as oil. It also is possible for one to reduce the chances of rust forming by using a dehumidifier or desiccant to help remove moisture from the air, but this usually is effective only in relatively small areas. 

Steel is often galvanized to prevent iron oxide from forming; this process usually involves a very thin layer of zinc being applied to the surface. Another process, called plating, can be used to add a layer of zinc, tin or chrome to the metal. Cathodic protection involves using an electrical charge to suppress or prevent the chemical reaction that causes rust from occurring.

What is a Metric Ton

A metric ton is a unit of measurement based on the metric system, rather than the standard system used in the United States. A metric ton is equivalent to 1,000 kilograms, and is strictly speaking a megagram, being one million grams.

The word most likely comes from the Latin word tunna, which is a word for a cask. Since a large cask full of something would weigh roughly a metric ton, this origin is commonly accepted. The word has been in use for quite some time, although previously the spelling was more often tunne.

The metric ton is often spelled as tonne, and in the United States may also be called a tonneau. A metric ton is not to be confused with the short ton unit, known simply as a ton in the system used in the United States. This ton is equal to 2000 pounds, or roughly 907kg. It should also not be confused with a long ton, a unit no longer in common usage in the United States, which is equal to 2240 pounds.

The official symbol for the metric ton in the International System of Units (SI) is simply ‘t’. Although all of the standard prefixes can be used with the metric ton, in practice the most common ones are the same ones used with the short ton. The kilotonne and megatonne are the only two units commonly seen outside of the metric ton itself. 

Kilotonne and megatonne may be used as metric for measuring energy release. This makes use of the metric ton by connecting it with the explosive TNT, as a way of calculating the force of an explosion. A metric ton of TNT releases roughly 4.19 X 10^9 Joules of energy, with a kilotonne releasing 4.19 X 10^12, and a megatonne releasing 4.19 X 10^15. To put this in some context, the Hiroshima bomb was equal to about twenty kilotonnes of TNT, while a modern nuclear missile could fall closer to the twenty megatonne range.

Because of the similarity in pronunciation — and in some circles, spelling — there can often be confusion between a short ton, a long ton, and a metric ton. In general, in the metric-using world the term ton or tonne alone will be used to refer to a metric ton, while the distinction long ton or short ton will be used to refer to the measure of the standard or Imperial system. In the United States, the term ton will be used to refer to a short ton, although in some industries — such as freight — a ton may be assumed to be a long ton. The term metric ton is then used to distinguish the metric unit. As a rule of thumb, it is a good idea to distinguish which unit of measurement you intend, if there is any doubt that your listeners might misconstrue your meaning.

What Is Rust

Rust is another name for iron oxide, which occurs when iron or an alloy that contains iron, like steel, is exposed to oxygen and moisture for a long period of time. Over time, the oxygen combines with the metal at an atomic level, forming a new compound called an oxide and weakening the bonds of the metal itself. 

Although some people refer to rust generally as "oxidation," that term is much more general; although rust forms when iron undergoes oxidation, not all oxidation forms rust. Only iron or alloys that contain iron can rust, but other metals can corrode in similar ways.

The main catalyst for the rusting process is water. Iron or steel structures might appear to be solid, but water molecules can penetrate the microscopic pits and cracks in any exposed metal. The hydrogen atoms present in water molecules can combine with other elements to form acids, which will eventually cause more metal to be exposed. 

If sodium is present, as is the case with saltwater, the corrosion is likely to occur more quickly. Meanwhile, the oxygen atoms combine with metallic atoms to form the destructive oxide compound. As the atoms combine, they weaken the metal, making the structure brittle and crumbly.

Some pieces of iron or steel are thick enough to maintain their integrity even if iron oxide forms on the surface. The thinner the metal, the better the chance that rusting will occur. Placing a steel wool pad in water and exposing it to air will cause rusting to begin almost immediately because the steel filaments are so thin. Eventually, the individual iron bonds will be destroyed, and the entire pad will disintegrate. 

Rust formation cannot be stopped easily, but metals can be treated to resist the most damaging effects. Some are protected by water-resistant paints, preventative coatings or other chemical barriers, such as oil. It also is possible for one to reduce the chances of rust forming by using a dehumidifier or desiccant to help remove moisture from the air, but this usually is effective only in relatively small areas. 

Steel is often galvanized to prevent iron oxide from forming; this process usually involves a very thin layer of zinc being applied to the surface. Another process, called plating, can be used to add a layer of zinc, tin or chrome to the metal. Cathodic protection involves using an electrical charge to suppress or prevent the chemical reaction that causes rust from occurring.

What is Viscosity

Viscosity is a scientific term describing the internal friction of a fluid or gas. Both have adjacent layers, and when pressure is applied, the friction between layers affects how much the substance will respond to external force. Viscosity, in its simplest form, can be evaluated by the thickness of a substance. A general rule is that gases are less viscous than liquids, and thicker liquids exhibit higher viscosity than thin liquids.

Viscosity may also be described as resistance of a liquid to penetration. Some refer to viscosity as the density of a liquid or gas. The term fluidity is opposite to viscosity, as it measures lack of resistance instead of amount of resistance.

Within each substance, the molecules reduce flow. They collide with each other, and also exhibit a degree of attraction. Molecular analysis can help determine specific viscosity measurements, thus helping to determine which substances will be of most use in a given application.

Temperature also effects viscosity. Raising the temperature of a fluid tends to make it less viscous. If one takes a thick liquid like molasses, and heats it up to boiling, the result will be a thin, easy to pour liquid. Cooking oils that are refrigerated, in most cases become more viscous, or almost solid due to colder temperatures, rendering them useless.

As crude oil is piped through climates of varying temperatures, the rate of flow in response to pressure changes. When oil is derived from Alaska, it is more viscous, than oil derived from the Persian Gulf, since the ground temperatures vary significantly. To address the issue of force needed to deliver oil through piping, sensors in some pipes measure the viscosity of the fluid and determine if greater or lesser pressure must be added to keep the flow of oil constant and steady. 

Naturally, motor oil is also subject to changing viscosity when heated by an engine. Oil that becomes too thin from the engine’s heat will not work properly in the car engine. To address this, scientists developed additives, called polymers, which keep viscosity rates constant under higher temperatures. 

Geologists use measurements of viscosity to evaluate magma under active or possibly soon to be active volcanoes. When magma exhibits a low level of viscosity, the volcano is more likely to erupt, because little pressure is needed to push the magma to the surface. Magma with greater viscosity causes volcanic eruptions less frequently. However if an eruption occurs with high viscosity magma, it results in huge explosions, since greater force is required to push magma outside of the volcano.

What Is Glycerin

Glycerin is a thick liquid that is colorless and sweet tasting. It has a high boiling point and freezes to a paste. Glycerin's most common use is in soap and other beauty products like lotions, though it is also used, in the form of nitroglycerin, to create dynamite.

This liquid is popular in beauty products because it is a humectant — it absorbs ambient water. This means that it can help seal in moisture. Not only is it used in the soap making process, it's a byproduct too. Many soap manufacturers actually extract glycerin during the soap making process and reserve it for use in more expensive products. 

Even when soap manufacturers extract glycerin, however, some amount remains in every bar of soap. Additional may be added to a bar of soap in order to produce a clear finish and extra moisturizing qualities. The extra also enhances the cleaning aspect of soap.

Glycerin can be dissolved easily into alcohol and water but not into oils. The pure chemical element is called Glycerol, which indicates that it is an alcohol. The impure commercial product is called glycerin.

The fact that is also easily absorbs water from the surrounding air means that glycerin is hygroscopic. If you were to leave some in the open, it would absorb water from the surrounding air to eventually become 20% water and 80% glycerin. If you were to place a small amount of pure glycerin on your tongue, your tongue would blister because it is dehydrating. When beauty products containing glycerin are used on skin that is well moisturized, it can help keep that moisture in. Where we get glycerin has changed over time. In 1889, for example, commercial candlemaking was the only way to obtain glycerin. At that time, candles made from animal fat which served as the source of glycerin. Extraction is a complicated process and there are various ways of going about it. The simplest way is to mix fat with lye. When the two are mixed, soap is formed and glycerin is then removed. Still, a small amount of glycerin remains in the soap. Glycerin has a variety of uses. As stated above, it can be used to make dynamite. It is not explosive alone, however, and it has to be processed before it can be used as an explosive. It's also used in prints and inks, preserved fruits, lotions and as a lubricant. It can also be used to prevent hydraulic jacks from freezing. Its antiseptic qualities permit its use in the preservation of scientific specimens.

What is Gravity

Essentially, gravity is an attractive force between objects. Most people are familiar with gravity as the reason behind things staying on the Earth's surface, or "what goes up, must come down," but gravity actually has a much vaster significance. Gravity is responsible for the formation of our Earth and all other planets and for the movement of all heavenly bodies. It is gravity that makes our planet revolve around the Sun, and the Moon revolve around the Earth.

Though humans have always been aware of gravity, there have been many attempts to accurately explain it throughout the years, and theories must regularly be improved upon to account for previously unconsidered aspects of gravity. Aristotle was one of the first thinkers to postulate the reason for gravity, and his and other early theories relied on a geocentric model of the universe, with the Earth at its center. Galileo, the Italian physicist who made the first telescopic observations supporting a heliocentric model of the solar system, with the Sun at the center, also made strides in the theory of gravity around the turn of the 17th century. He discovered that objects of varying weights fall towards the Earth at the same speed. 

In 1687, English scientist Sir Isaac Newton published his law of universal gravitation, which is still used to describe the forces of gravity in most everyday contexts. Newton's first law states that the force of gravity between two masses is directly proportional to the product of the two masses and inversely proportional to the square of the distance between them, or mathematically: F=G(m₁m₂/d²), where G is a constant. 

Newton's second law states that gravitational force is equal to the product of a body's mass and its acceleration, or F=ma. This means that two masses that are gravitationally attracted to each other experience the same force, but that it translates into a much greater acceleration for a smaller object. Therefore, when an apple falls towards the Earth, both the Earth and the apple experience equal force, but the Earth accelerates towards the apple at a negligible speed, since it is so much more massive than the apple. 

Around the late 19th century, astronomers began to notice that Newton's law did not perfectly account for observed gravitational phenomena in our solar system, notably in the case of Mercury's orbit. Albert Einstein's theory of general relativity, published in 1915, resolved the issue of Mercury's orbit, but it has since been found to be incomplete as well, as it cannot account for phenomena described in quantum mechanics. String theory is one of the foremost modern theories to explain quantum gravity. Though Newton's law is not perfect, it is still widely used and taught because of its simplicity and close approximation of reality. 

Because gravitational force is proportional to the masses of the two objects experiencing it, different heavenly bodies exert stronger or weaker gravitational force. For this reason, an object will have different weights on different planets, being heavier on more massive planets and lighter on less massive planets. This is why humans are much lighter on the Moon than they are on the Earth.

It's a popular misconception that astronauts experience weightlessness during space travel because they are outside the field of gravitational force of a large body. In fact, weightlessness during space travel is actually achieved because of free fall — the astronaut and the space shuttle or rocket are both falling (or accelerating) at the same speeds. The same speed gives the notion of weightlessness or floating. This is the same concept as a person on a "free fall" ride at an amusement park. Both the rider and the ride are falling at the same speed causing the rider to seem as though he is falling independent of the ride. The same feeling can be experienced while riding an airplane or an elevator that suddenly breaks from its normal rate of decent.

What Is Buoyancy

Buoyancy is the ability of an object to float in a liquid. The relation of the object's weight to the weight of the water displaced is what determines if the object will float; although the size and shape of the object do have an effect, they are not the primary reason why an object floats or sinks. If an object displaces more water than its weight, it will float. Buoyancy is an important factor in the design of many objects and in a number of water-based activities, such as boating or scuba diving.

The Archimedes Principle

The mathematician Archimedes, who lived in the third century B.C., is credited with discovering much of how buoyancy works. According to legend, he was getting into a bath one day and noticed that the more he immersed himself in the water, the more its level rose. He realized that his body was displacing the water in the tub. Later, he determined that an object under water weighed less than an object in air. Through these and other realizations, he established what came to be known as the Archimedes Principle:

An object in fluid is buoyed up by a force equal to the weight of the fluid the object displaces.

Positive, Negative, and Neutral Buoyancy An object that floats in a liquid is positively buoyant. This means that the amount of water displaced by the object weighs more than the object itself. For example, a boat that weighs 50 lbs (23 kg) but displaces 100 lbs (45 kg) of water will easily float. The boat displaces more water than its weight in part because of its size and shape; most of the interior of a boat is air, which is very light. This explains why massive ocean liners float: as long as the water displaced weighs more than the ships themselves, they will not sink. Negative buoyancy is what causes objects to sink. It refers to an object whose weight is more than the weight of the liquid it displaces. For example, a pebble may weigh 25 grams, but if it only displaces 15 grams of water, it cannot float. If the 50 lbs (23 kg) boat was loaded down with 75 lbs (34 kg) of freight, it would no longer float because its weight (125 lbs or 56.69 kg) is heavier than the weight of the water it displaces (100 lbs or 45 kg). It is also possible for an object to be neutrally buoyant. This means that the object's weight and the amount of liquid it displaces are about the same. A neutrally buoyant object will hover in the liquid, neither sinking nor floating. A submarine can adjust it weight by adding or expelling water in special tanks called ballast tanks. By properly balancing its ballast, the sub can hover at various levels under the surface of the water without sinking. Size and Shape How much of an object's surface touches the water has an effect on its buoyancy. A very large ship has a lot of surface area, which means that the ship's weight is spread out over a lot of water, all of which is pushing up on the ship. If the same ship was in the water with the bow pointing down, it would start to sink because all of the weight is concentrated in one small area, and the water it is displacing weighs less than the weight of the ship. A common example used to demonstrate this is a person floating in water. If the person floats on her back, her entire body can stay at or near the water's surface. When she floats in the water with her feet down, she'll sink farther; typically, only her upper body will stay at the top of the water. Stability Stability in a fluid depends on the location of an object's center of buoyancy in relation to its center of gravity. An object's center of gravity is the point in the object where all of the object's weight appears to be concentrated; it can also be thought of as the average location of the object's weight. The center of buoyancy is the center of gravity of the water that the object has displaced. This is not in the water, but in the object floating on it. When the center of buoyancy is directly above the center of gravity, then the object will be stable. If, however, the center of gravity is above the center of buoyancy — as in a ship that is loaded with freight high above the water line — then the object becomes unstable. If the freight shifts to one side for any reason, the center of gravity and the center of buoyancy will no longer line up. The ship will tip over as the center of buoyancy tries to rise above the center of gravity again. In the human body, the center of gravity is usually in the area of the navel. The center of buoyancy is slightly higher, which is why a body tends to float upright with the shoulders and torso above the legs. Turned upside down, where the legs are above the torso, the body's center of gravity is above the center of buoyancy. This makes the body unstable, and the position can only be maintained through effort. Buoyancy in Practice By applying the principles of buoyancy, engineers can design boats, ships, and seaplanes that remain afloat and stable in water. This is true of many other objects, such as life preservers and pontoons. Just about anything designed for water relies on an understanding of these principles. Many swimmers know that there are ways to make their bodies more buoyant, such as lying on their backs or holding a full breath. In addition, trying to dive to the bottom of a pool takes effort because the body naturally floats. Scuba divers in particular need to know how to float, hover, and sink, and they often wear extra weights and other gear to help them manage these maneuvers.

What Is Urea

Urea, also called carbamide, is an organic chemical compound, and is essentially the waste produced by the body after metabolizing protein. Naturally, the compound is produced when the liver breaks down protein or amino acids, and ammonia; the kidneys then transfer the urea from the blood to the urine. Extra nitrogen is expelled from the body through urea, and because it is extremely soluble, it is a very efficient process. The average person excretes about 30 grams of urea a day, mostly through urine, but a small amount is also secreted in perspiration. Synthetic versions of the chemical compound can be created in liquid or solid form, and is often an ingredient found in fertilizers, animal feed, and diuretics, just to name a few.

Discovery

Naturally, the chemical compound is not only produced by humans but also by many other mammals, as well as amphibians and some fish. Discovered in 1773 by the French chemist Hillaire Rouelle, urea became the first organic compound to be synthetically formulated. German chemist Friedrich Wöhler, one of the pioneers of organic chemistry, invented the process to create the synthetic version of the compound in 1828, just 55 years after its discovery. 

Production

The synthetic version of the compound is created from ammonia and carbon dioxide and can be produced as a liquid or a solid. In 1870, the process of producing the compound synthetically by dehydrating ammonium carbamate under conditions of high heat and pressure was invented, and this process is still used today. There are many common uses of the synthetic compound, and therefore its production is high; in fact, approximately one million pounds of urea is manufactured in the United States alone each year.

Common Uses

Most of the manufactured compound is used in fertilizers; when nitrogen is added to urea, the compound becomes water soluble, making it a highly desired ingredient for lawn fertilizer. The synthetic version is also used commercially and industrially to produce some types of plastics, animal feed, glues, toilet bowl cleaners, dish washing machine detergents, hair coloring products, pesticides, and fungicides. Medicinally, it is used in barbiturates, dermatological products that re-hydrate the skin, and diuretics Physicians can use urea levels to detect diseases and disorders that affect the kidneys, such as acute kidney failure or end-stage renal disease (ESRD). The blood urea nitrogen (BUN) and the urine urea nitrogen (UUN) tests, which measure urea nitrogen levels in the blood and urine, are often used to assess how well a patient's kidneys are functioning. Increased or decreased levels of the compound, however, do not always indicate kidney problems, but instead may reflect dehydration or increased protein intake.

Why is Alcohol a Good Antiseptic

Ethyl alcohol, more frequently known as grain alcohol, works as an antiseptic by coagulating protein, the primary material that makes up cells. Although alcohol cannot coagulate every single cell, it functions well to inhibit the growth and reproduction of many microorganisms, including bacteria, fungi, protozoa, and viruses.

Intriguingly, 70% alcohol is a more effective antiseptic than 100% alcohol. Because alcohol causes protein to coagulate on contact, a 100% solution coming into contact with a microorganism creates a hardened protein wall around the outside of the organism, rather than permeating into its interior. Because microorganisms can be very resilient, this protein shell only causes dormancy rather than death. This can lead to revival and a continuation the cycle of reproduction under the right circumstances. At a purity of 70%, however, the alcohol causes coagulation to occur more gradually, slowing down the microorganism from the inside out.

Human skin cells are more resistant to alcoholic coagulation than most microorganisms. This is why your skin doesn't coagulate if it comes into contact with alcohol. Alcohol is also a good solvent that dissolves and carries away non-organic impurities that are responsible for things like odor. Its antiseptic action does cause a burning sensation on open flesh, as anyone who has ever used alcohol to clean a wound can testify.

Alcohol is an ideal antiseptic because it achieves its goal subtly through coagulation, rather than through some active means like active poisoning or dissolving. Throwing acid on an open wound would only be successful at removing the contaminating microorganisms at the expense of a decent chunk of flesh. Ethyl alcohol should never be confused with methyl alcohol, also known as methanol or wood alcohol. Methyl alcohol is used in industry as a solvent, and should never be used for any medical reason. Even small quantities can cause blindness or paralysis, and large quantities can be fatal.

What is G-Force

G-force refers to either the force of gravity on a particular celestial body or the force of acceleration anywhere. G-force is measured in g's, where 1 g equals the force of gravity at the Earth's surface (9.8 meters per second per second). As Einstein realized, the force of gravity and the forces of acceleration are mutually indistinguishable on the subject; a person in an opaque box experiencing a g-force would be unable to tell whether its origin lies in acceleration through space or a gravitational field unless they had some way of peeking outside the box. 

Analysis of g-forces are important in a variety of scientific and engineering fields, especially planetary science, astrophysics, rocket science, and the engineering of various machines such as fighter jets, race cars, and large engines. 

Humans can tolerate localized g-forces in the 100s of g's for a split second, such as a slap to the face. However, sustained g-forces above about 10 g can be deadly or lead to permanent injury. There is considerable variation among individuals when it comes to g-force tolerance, however. Race car drivers have survived instantaneous accelerations of up to 214 g during accidents. In rocket sled experiments designed to test the effects of high acceleration on the human body, Colonel John Stapp in 1954 experienced 46.2 g for several seconds. Usually, accelerations beyond 100 g, even if momentary, are fatal.

In everyday life, humans experience g-forces stronger than 1 g. A typical cough produces a momentary g-force of 3.5 g, while a sneeze results in about 3 g of acceleration. Roller coasters are usually designed not to exceed 3 g, although a few notable exceptions produce as much as 6.7 g. Slight increases in g-force are experienced in any moving machinery, such as cars, trains, planes, and elevators. Astronauts in orbit experience 0 g, called weightlessness.

G-force varies on different planets or celestial bodies. When an object has a greater mass, it produces a higher gravitational field, resulting in higher g-forces. The g-force on the Moon is about 1/6 g, on Mars about 1/3 g. On the Martian satellite Deimos, only 13 km (8 mi) in diameter, the g-force is about 4/10,000ths of a g. In contrast, the surface of Jupiter experiences a g-force of about 2.5 g. This is smaller than it seems it should be because Jupiter's low density causes its surface to be very far from its primary concentration of mass at the core. On the surface of a neutron star, a degenerate star with a density similar to the atomic nucleus, the surface gravity is between 2×10¹¹ and 3×10¹² gs.

What is a Non-Newtonian Fluid

A non-Newtonian fluid is a fluid whose viscosity is variable based on applied stress. The most commonly known non-Newtonian fluid is cornstarch dissolved in water. Contrast with Newtonian fluids like water, whose behavior can be described exclusively by temperature and pressure, not the forces acting on it from second to second. Non-Newtonian fluids are fascinating substances that can be used to help us understand physics in more detail, in an exciting, hands-on way.

If you punch a bucket full of a shear thickening non-Newtonian fluid, the stress introduced by the incoming force causes the atoms in the fluid to rearrange such that it behaves like a solid. Your hand will not go through. If you shove your hand into the fluid slowly, however, it will penetrate successfully. If you pull your hand out abruptly, it will again behave like a solid, and you can literally pull a bucket of the fluid out of its container in this way. 

A shear thinning non-Newtonian fluid behaves in the opposite way. In this type, the fluid becomes thinner, rather than thicker, when stress is applied. Also called pseudoplastic, examples of this type of non-Newtonian fluid include ketchup, toothpaste, and paint. The effect doesn't usually last for long in either type, continuing only as long as the stress is applied.

Non-Newtonian fluids help us understand the wide variety of fluids that exist in the physical world. Plastic solids, power-law fluids, viscoelastic fluids, and time-dependent viscosity fluids are others that exhibit complex and counterintuitive relationships between shear stress and viscosity/elasticity. However, non-Newtonian fluid is probably the most exciting to play with. 

A search for non-Newtonian fluid on YouTube brings up some interesting results. On several game shows, hosts or contestants run across big vats of shear thickening non-Newtonian fluid, able to traverse them unless they stop - in which case they sink immediately. When combined with a oscillating plate, non-Newtonian fluids demonstrate other unusual properties, like protruding "fingers" and holes that persist after creating them. An oscillating plate applies stress on a periodic basis, rapidly changing the viscosity of the fluid and putting it in an odd middle ground between a liquid and a solid.

A practical application for shear thickening non-Newtonian fluids may be in body armor of the future. Since such fluids are usually flexible, they would allow soldiers to move freely when not under attack. But if confronted with a speeding bullet, they would quickly harder, performing like traditional armor. More research is necessary to see if non-Newtonian fluids are suitable for the military, but until then, it's sure fun to play with.

What is Thermal Energy

Thermal energy is generated and measured by heat of any kind. It is caused by the increased activity or velocity of molecules in a substance, which in turn causes temperature to rise accordingly. There are many natural sources of thermal energy on Earth, making it an important component of alternative energy.

The laws of thermodynamics explain that energy in the form of heat can be exchanged from one physical object to another. For instance, putting fire under a pot of water will cause the water to heat up as a result of the increased molecular movement. In that way, the heat, or thermal energy, of the fire, is partially transmitted to the water.

Understanding the principles of thermodynamics has allowed human beings to harness natural sources of heat to create thermal energy out of a variety of sources. The sun, ocean, and geothermal sources such as geysers and volcanoes, can all be sources of thermal energy. As humans attempt to turn to sustainable forms of alternative energy instead as fossil fuel resources become depleted, much attention has been focused on improving methods of harnessing thermal energy to power human activity.

Solar thermal power is one of the most commonly used forms of thermal energy. Although gathering solar power is only available when the sun is visible in the sky, scientists have developed many different ways of storing and utilizing the power absorbed by solar devices. On a small level, a person can heat his or her pool by placing low-temperature collecting systems in or around the water. By absorbing sunlight and distributing it to the water, the temperature is increased throughout the day and even after the sun has set. Solar panels, evaporation pools, and other advanced systems can perform this function on a much more wide-spread level, creating enough stored power to run a factory or even city on solar thermal power.

The Earth is constructed around a molten core of incredible heat that lessens considerably as it reaches the surface or crust level. Yet by harnessing some of the heat generated below the surface of the planet, humans can extract enormous amounts of energy. The simplest way to do this is through geothermal energy sources such as geysers, or at the boundaries of tectonic plates. Geothermal wells pump out energy in the form of hot water or steam that can be converted into usable energy, or simply used directly. 

Thermal energy is an awesome force that is just beginning to be fully understood. By creating new devices and methods to concentrate, store, and transport naturally-created thermal energy, human beings can reduce dependence on non-sustainable forms of energy. Thanks to the power of heat, hot baths, boiled water, and thermally-powered cities are all possible.

Why Does Bread get Moldy

Bread gets moldy because it provides a good source of food for some types of fungus. The air is usually full of tiny mold spores, and under the right conditions, they can settle on nearly any organic substance and start to digest it. In bread, these enzymes break down the cell walls of the organic material making up the loaf, releasing easily digestible, molecularly simple compounds. This is how bread gets moldy.

Mold, found on old or unrefrigerated bread, comes from fungi, one of the most ubiquitous and successful forms of life on the planet. There are dozens of thousands of species, which can be found practically everywhere. Scientists who study fungi, called mycologists, tell say that approximately one out of every 20 living species is a form of fungus.

Fungi cannot receive energy directly from the sun because they do not have chlorophyll, and must therefore live off other plants and animals. Some fungi are parasites, actively attacking a host for nutrients. Most, however, are scavengers, turning organic matter into soil. Without fungi, many plants would die, because they require rich soil to thrive.

Most fungi tend to be flexible about their food choices. They feed on a wide variety of organic molecules, and their flexibility is largely responsible for their ubiquity. Fungi produce dozens of digestive enzymes and acids, which they secrete into a material as they grow over it. 

Unlike humans, mold digests first, then eats, rather than vice versa. Under the right conditions, there exist forms of fungi that eat practically anything but metal. Special fungi produced through selective breeding are sometimes used as agents to target specific compounds for cleanup. 

Fungi reproduce exponentially until all available nutrients are exhausted. Some forms of mold can double their mass every hour. They reproduce by means of spores, tiny vectors which are produced by the fungus en masse. Spores are extremely small and numerous — there are probably millions of fungal spores in any room at one time. 

Luckily, these spores can be destroyed by cooking, which is why bread doesn't immediately get infected with mold. Over time, however, airborne spores find their way onto the nutrient-rich surface of bread and start multiplying — even under the cold conditions of a refrigerator. At freezing point, fungi become dormant. If they are exposed to heat again, they can revive and continue to grow.

What are Hypnagogic Hallucinations

Hypnagogic hallucinations are hallucinations which occur at the boundary between sleeping and waking. They can occur when people are falling asleep, or when they are starting to wake up, and they tend to be extremely vivid, feeling like a Technicolor Oz after the black and white Kansas of every day life. Many people experience hypnagogic hallucinations at some point during their lives, but recurrent intense hallucinations can be a sign of an underlying medical condition which may require treatment.

Visual, auditory, tactile, and kinetic sensations can all be experienced during hypnagogic hallucinations, and everyone experiences slightly different forms. Some people, for example, may feel like they are falling, and jerk themselves awake to avoid hitting the ground. Others may hear voices as they are trying to drift off to sleep, or experience a vivid sensation that someone or something is in the room. Sensory experiences such as feeling like one is submerged in a pool of water are also not uncommon.

In some cases, hypnagogic hallucinations can be frightening for the people who experience them. They may include vivid and frightening images, including images which are out of scale, which can make the hallucinations seem even more unsettling; people may see giant spiders on the walls, for example, or feel like they have shrunk down to a tiny size in the bed. The vivid experiences may also be brought to mind over the course of the day, causing inexplicable images or sensations to filter through someone's consciousness at an unexpected moment.

The cause of hypnagogic hallucinations is not fully understood. These hallucinations tend to be more common in people with sleep disorders, especially narcolepsy, but they can also appear as a side effect related to prescription drugs, and drug abusers often experience them as well. Hypnagogic hallucinations tend to be more common in young people, especially children, which may be because their minds are still developing and forming pathways, which can occasionally lead to some crossed wires.

If someone experiences numerous hypnagogic hallucinations, repetitive or not, it is a good idea to see a doctor to check for health problems which could be related to the experiences. If no cause is evident, a psychologist or similar mental health professional might be able to explore the subconscious causes and help the patient deal with the hallucinations. Consulting a psychologist can also yield useful tips for people who are shaken or upset by hypnagogic hallucinations, even if the hallucinations continue to occur.

What is Benedict's Reagent

Benedict's reagent is a chemical compound made up of copper sulfate, which can detect the presence of glucose or fructose. A reagent is a chemical that is applied to another substance in order to produce a chemical reaction that can give valuable information regarding the substance. Benedict's reagent is most commonly used to calculate ways of reducing glucose or fructose in foods. In the past, it was the way diabetes was detected through the testing of urine.

In food tests, a small amount of the food is added to Benedict's reagent and boiled for several minutes to test the amount of sugar present. The results will show precipitates, or solid formations within the tested substance. The amount to which a precipitate is present can show the exact glucose or fructose present in the substance. 

Since the precipitates are likely to be very small, Benedict's reagent also shows color changes that can gauge the amounts of the sugars glucose and fructose. For example, a substance treated with Benedict's reagent that is green shows very little or possibly no glucose or fructose present. On the other hand a red color indicates a high quantity of these sugars.

In people who are suspected of having diabetes, analysis of urine is one of the main diagnostic method. Pregnant women used to undergo an analysis of urine that was treated with Benedict's reagent to check for gestational diabetes. Today, other tests may be used because they are more precise in measuring sugar levels. 

Pregnant women may resent these frequent urine tests but they are in fact very important to rule out diabetic conditions during a pregnancy. Benedict’s reagent only works so far in diabetic testing however, since presence of fructose in the urine does not suggest a diabetic condition.

Thus, urine must be further tested, if it shows positive when mixed with Benedict's reagent to evaluate for the presence of glucose. For some, this may mean no further testing with Benedict's reagent, but drinking a glucose solution that most find quite distasteful. However, untreated diabetes should not go unchecked. Thus, diagnosis is extremely valuable and may help begin early treatment, which can significantly change later outcome.

What is a Wind Farm

A wind farm is a collection of windmills or turbines which are used to generate electrical power through their mechanical motions as they are pushed by the wind. Both Europe and the United States have large numbers of wind farms, and the technology is also found on other continents. In Asia, India especially has devoted a great deal of funding to establishing wind farms. The energy generated by a wind farm can be fed directly into the general energy grid after passing through transformers.

As a potentially large source of renewable energy, wind farms are particularly popular in nations which are focusing on alternative energy. Other types of renewable energy include wave power and solar arrays. All of these technologies take advantage of already existing energy, converting it into a usable form. Since a wind farm does not actively deplete resources as it generates power, it is considered a form of “green” energy.

Naturally, some resources must be expended to create a wind farm. The turbines, transformers, and grid system on a wind farm are often made from less than ideal substances, such as metals mined in an unclean way. However, once installed, a wind farm requires no additional energy output other than that required for basic maintenance. This is a marked contrast to a power plant which relies on coal or petroleum products. Consumers who want to support wind farms can buy energy credits which go to developers of wind farms.

Naturally, the best place for a wind farm is a windy location. In some instances, a windy location may also be generally unusable or uninhabitable. In other instances, a wind farm may take up useful real estate which could be used for farming. This has led to some criticism of wind farms, since they take up a great deal more space than a comparable non-renewable energy generating facility. In addition, wind farms pose a severe threat to migratory birds, as has been clearly documented by several scientific organizations.

These issues aside, the technology is generally believed to be environmentally sound and fiscally viable. Especially if wind farms are combined with other renewable energy sources, green energy could make up a bulk of the power grid. This could have a huge impact on the environment and on society in general. Especially at the end of the twentieth century, when a growing number of citizens began to call for energy reforms, wind farms held a great deal of promise.

What Is a BTU

BTU, short for British Thermal Unit, is a basic measure of thermal (heat) energy. One BTU is the amount of energy needed to heat one pound of water one degree Fahrenheit, measured at its heaviest point. In other words, if you placed 16 ounces of water at 59°F into a stovetop pan and turned on the gas burner, it would take one BTU to raise the temperature of the water to 60°F. As more BTUs continue to flow from the gas flame, the water will eventually reach the boiling point of 212°F. 

A BTU is also the equivalent of 252 heat calories, not to be confused with the kilo-calories of food, and of approximately a third of a watt-hour. When speaking of cooling power, the BTU also works in reverse. The air-cooling power of an air conditioning system refers to the amount of thermal energy removed from an area. Hence a 65,000 BTU heater and a 65,000 BTU air conditioner are of roughly the same capacity and size. The higher the BTU output, the more powerful the heating or cooling system.

Strangely enough, the British Thermal Unit is rarely used in Great Britain anymore, where it is considered a non-metric measurement. Even in countries which use the BTU as a standard measurement, there is some disagreement over the formula used to derive it. The thermal energy needed to raise water one degree Fahrenheit can depend on the original temperature and the method used for heating. Therefore, it is possible to get several different definitions of a BTU from different sources. This rarely has a palpable effect on consumer product information, however.

Most heating and cooling systems produce thousands of BTUs, almost rendering the measurement of one BTU pointless. One is more likely to encounter smaller BTU figures during scientific experiments, where the slightest change in thermal energy may need to be calculated in terms of calories. When dealing with central air conditioning units and commercial pizza ovens, however, the BTU numbers can easily reach the hundreds of thousands. A unit of measure called the MMBTU is the equivalent of a million BTUs. Few man-made objects can generate this level of thermal energy, however.

When shopping for heating or cooling systems, keep in mind that even the smallest window-mounted air conditioner or space heater can produce thousands of BTUs. The BTU numbers should primarily be used as a comparison between systems. Larger and more expensive systems should provide significantly higher BTUs than smaller ones. When deciding between similarly priced units, compare the BTUs for a better gauge of performance.

What are Organic Compounds

Organic compounds are the complex compounds of carbon. Because carbon atoms bond to one another easily, the basis of most organic compounds is comprised of carbon chains that vary in length and shape. Hydrogen, nitrogen, and oxygen atoms are the most common atoms that are generally attached to the carbon atoms. Each carbon atom has 4 as its valence number which increases the complexity of the compounds that are formed. Since carbon atoms are able to create double and triple bonds with other atoms, it further also raises the likelihood for variation in the molecular make-up of organic compounds.

All living things are composed of intricate systems of inorganic and organic compounds. For example, there are many kinds of organic compounds that are found in nature, such as hydrocarbons. Hydrocarbons are the molecules that are formed when carbon and hydrogen combine. They are not soluble in water and easily distribute. There are also aldehydes – the molecular association of a double-bonded oxygen molecule and a carbon atom. 

There are many classes of organic compounds. Originally, they were believed to come from living organisms only. However, in the mid-1800s, it became clear that they could also be created from simple inorganic proteins. Yet, many of the organic compounds are associated with basic processes of life, such as carbohydrates, proteins, nucleic acids, and lipids. 

Carbohydrates are hydrates of carbon and include sugars. They are quite numerous and fill a number of roles for living organisms. For example, carbohydrates are responsible for storing and transporting energy, maintaining the structure of plants and animals, and in helping the functioning of the immune system, blood clotting, and fertilization – to name just a few. 

Proteins are a class of organic compounds that are comprised of carbon, hydrogen, nitrogen, and oxygen. Proteins are soluble in water. The protein itself is composed of subunits called amino acids. There are 20 different amino acids found in nature – organisms can convert them from one to another for all but eight of the amino acids. 

Lipids comprise a class of organic compounds that are insoluble in water or other polar solvents; however, they are soluble in organic solvents. Lipids are made of carbon, hydrogen, oxygen, and a variable of other elements. Lipids store energy, protect internal organs, provide insulation in frigid temperatures, among other features. Lipids can be broken down into several groups ranging from triglycerides, steroids, waxes, and phospholipids. 

Nucleic acids are another group of organic compounds. They are universal in all living organisms. In fact, they are found in cells and viruses. Some people may not consider a virus to be a living thing. Friedrich Miescher discovered nucleic acids in 1871.

What is UV Light

UV light, short for ultraviolet light, is light with a wavelength shorter than that of visible light, but longer than X-rays. This means electromagnetic waves with a wavelength between 400 nm and 10 nm, with energies from 3 eV to 124 eV. UV light is more energetic than visible light and has a shorter wavelength, letting it penetrate more readily through obstacles. The "ultraviolet" in ultraviolet light references that UV light is beyond violet on the electromagnetic spectrum. Like other forms of electromagnetic radiation outside the visible spectrum, UV light is invisible, but it can be observed indirectly by the way it makes many other substances fluoresce in the visible spectrum. 

In popular culture, UV light is primarily thought of as a party light because of the way it makes textiles and clothing, particularly white shirts, fluoresce brightly. "Black lights" are synonymous with UV light. These lights primarily produce light in the UV portion of the spectrum, but they also produce a slight violet glow. Special posters or other works of art are often created with the express purpose of fluorescing a certain way under a black light. 

UV light has many other applications outside of the party scene. It is frequently used in security. For instance, sensitive documents, such as currency, driver's licenses, credit cards or passports, have invisible symbols on them that light up only in the presence of UV light. These are difficult for counterfeiters to copy.

Common fluorescent lamps are powered by UV light. UV light is produced by ionizing low-pressure mercury vapor, which is then absorbed by a special fluorescent coating, which in turn produces visible light. Fluorescent lights are more energy-efficient than conventional light bulbs. 

Biologists and zoologists are quite fond of UV light as it helps them take nighttime organism surveys in the field. Certain birds, reptiles, and insects (such as bees) are clearly visible under UV light, and quickly flashing a UV light over a small area can allow observers to count the approximate number of organisms of a given type in that area. This is very helpful because many animals are highly nocturnal and rarely if ever seen during the day. 

Besides the above mentioned applications, UV light can also be used for spectrophotometry (to analyze chemical structure), analyzing minerals, chemical markers, photochemotherapy (for psoraisis), very fine resolution photolithography, checking electrical insulation, sterilization, disinfecting drinking water, food processing, lasers, and many other areas.

What is Chromatography

Chromatography is a process which can be used to isolate the various components of a mixture. There are a number of different types of chromatography in use, including gas, liquid, paper, and gel permeation chromatography, and this process can get quite involved, especially with complex mixtures. It is also an extremely useful addition to a variety of fields, including pure and applied sciences, forensics, and athletics, among many others.

The process relies on the fact that different molecules will behave in different ways when they are dissolved in a solvent and moved across an absorbent medium. In a very simple example, one could take ink and make a mark on a piece of paper. The paper could be dipped into water, and the capillary action of the water would pull the ink through the paper. As the ink moved, its ingredients would separate out, revealing a distinctive pattern which could be used to determine the components of the ink.

In preparative chromatography, researchers separate individual components of a compound for use in the lab or in research. This process can get extremely precise: using a preparative chromatography technique, for example, a scientists can isolate two strands of DNA which differ by only a few pieces of information. In analytical chromatography, the goal is to figure out what is in a sample. Drug testing relies on analytical chromatography to isolate illicit substances in urine and blood samples, for instance.

In the example above with a dot of ink and a piece of paper, the basic concepts behind the process are illustrated, although most chromatography machines are a bit more sophisticated. It is important to choose the right solvent or carrier fluid to dissolve the sample in, and to select an appropriate solid medium to pass the sample through. Poor choices can result in confusing or inaccurate results, and the chromatography procedure requires substantial skills on the part of the operator to ensure that it returns useful data.

The result of a session is a chromatograph, a printout which provides information about the substance being analyzed. The printout usually takes the form of a chart with a series of troughs and peaks. Each peak represents a substance present in the sample, and the concentrations of these substances can be determined by looking at the height and width of the peak. Computerized chromatography machines generate such printouts automatically as the data is produced, and they can also be made by hand.

What Are Cilia

The term cilia is Latin for "eyelashes." Common in single-cell organisms, these hair-like structure wave to move the cell around or to move something around the cell. Cilia also are present on most cells in the human body. Some tissues in the body, such as the Fallopian tubes in women and the trachea, also have a special type of cilia that help transport substances along the tissues' surfaces.

Types of Cilia in the Body

In the body, cilia on the surface of tissues are responsible for protecting a person from germs in the lungs and for pushing an ovum through the Fallopian tube, among other tasks. These cilia are called motile cilia, and they are found in groups and beat in waves. Primary cilia, on the other hand, usually are found only one at a time on cells.

Structure

The structure of a single cilium is much like a tube, and its long fibers are called microtubules. These microtubules often pair up to form doublets, which in turn form a ring. The cross-section of doublets of microtubules looks like a figure 8, because the two microtubules stick together along a line. Nine doublets form the larger ring in what is known as a 9-2 pattern. When kinesin binds to one side of the doublets and not the other, the cilium flexes and curves, similar to the way a person's skeletal muscles contract. 

Functions

Single-celled eukaryotes, which are organisms with cells that have a nucleus, often use cilia to move through liquid. This type of organism is surrounded by a cytoskeleton, made of protein filaments that allow the cell to hold its shape. A cilium attaches to the cytoskeleton of the cell with a basal body, the way a root attaches hair to human skin. 

The rhythm of waving cilia is controlled by centrioles, which are organelles located inside the cell wall. Mitochondria, other units inside the cell, provide adenosine triphosphate (ATP), a source of cellular energy, for the cilia. The ATP directs the chemical kinesin to bind to certain parts of the cilia that control their movement. Thus, the cilia are able to beat or essentially swim their way through viscous liquid.

Flagella

Similar to cilia, flagella are longer such hairs, usually found in ones or twos, such as the tail of a sperm. They share many characteristics with cilia, but they also occur on prokaryotes, which are organisms with cells that do not contain a nucleus. Some eukaryotes that use cilia and flagella to move are also found in ferns, on algae, on bacteria and inside many animals. This adaptation originally allowed independent cellular creatures, such as paramecia, to move around in search of food, rather than wait until food came to them. Cells that are part of larger systems have continued to use cilia to their advantage.

What Are the Pros and Cons of Genetically Engineered Food

Genetically engineered food, also known as Genetically Modified or GM food, is food that has been altered at the genetic level to produce a better tasting, longer lasting, or more resistant product. Vegetables and other crops are the most common type of genetically engineered food. Corn, for example, has been altered to be naturally insect-resistant, while tomatoes have been modified to slow down the rotting process. Genetically engineered food has its pros and cons, which include:

PROS

1. Genetically engineered food is cost effective. Because it is designed to resist pests and prosper under non-optimal conditions, it can also help people in areas where regular crops would not prosper. Large savings in production may lead to financial gain and help fight poverty.
2. Genetically engineered food can be naturally pest-resistant and thus reduce the need for additional chemicals, pesticides, and other dangerous additives.
3. Genetically engineered food may help reduce world hunger, at least in theory. As new species are altered to grow faster or more effectively, they can be used to feed poor nations or chosen for countries where crops may not normally prosper because of less than desirable environmental conditions. Some companies now claim to be producing crops that can help against certain diseases or provide specific nutrients, such as milk proteins and iron, which would otherwise not be available to some populations.

CONS

1. Genetically engineered food is too new for us to know if it may have an effect on the human body. Modifying the essence of a food may also alter the dynamics of it in ways not known. Since many of the alterations include adding chemical properties to the crops, some people fear what effect those same chemicals may have on us.
2. Poor countries will not have easy access to genetically engineered food unless directly given to them, which means that the world's richest nations will control the market. This may result in a high dependency on the side of the poor nations, which will in turn lead to a broken economy.

What is a Faraday Cage

It's very likely you woke up this morning in a Faraday cage, made your breakfast in another Faraday cage, and drove a Faraday cage to work. Depending on your particular job, you may have spent much of your day in front of yet another Faraday cage.

The concept of a Faraday cage is logically attributed to Michael Faraday, an 19th Century pioneer in the field of electromagnetic energy. Faraday studied the work of earlier scientists such as Benjamin Franklin and theorized that electromagnetic waves naturally flowed around the surface of conductive materials, not through them. For example, if a metal box containing a mouse were placed directly in the path of an electrical current, the electricity would flow over the box but not into the compartment with the mouse. The mouse would not be electrocuted. Such a box would be considered a Faraday cage.

The important concept to remember is that a Faraday cage acts as a shield against the effects of electromagnetic energy. When a car is struck by lightning, the metal frame becomes a Faraday cage and draws the electricity away from the passengers inside. A microwave oven's door has a screen which prevents electromagnetic energy from escaping into the room. Electronic parts which generate radio frequencies are often protected by Faraday cages called RF shields. Even a concrete building reinforced with lead or rebar can be considered a Faraday cage.

Few consumers of electronic products would ever ask the sales clerk for a Faraday cage, but designers and engineers understand the importance of electromagnetic shielding very well. Whenever sensitive electronic parts are used in machinery, some form of shielding is generally in place, whether it be the machine's metal shell, a capsule or a grounding wire. If the electronic parts generate electromagnetic energy of their own, a Faraday cage must be used to shield users from excessive exposure. This is why cell phone use is often discouraged in hospitals or other public places with electronic equipment. Unshielded equipment may be exposed to the microwave energy created by cell phones or other radio transmitters.

What Is Vegetable Glycerin

Vegetable glycerin is also known as vegetable glycerol. It is a carbohydrate that is usually derived from plant oils. It is used as a sweetener and as an ingredient in a number of cosmetic products. Vegetable glycerin is also used in place of alcohol to extract botanicals.

Glycerin is an organic compound composed of three carbon atoms, hydrogen atoms, and three OH groups. These OH groups form hydrogen bonds with water, slowing down its movement and giving liquid glycerin the property of a syrup. It is also resistant to freezing, a property used in storing sensitive liquids, such as enzymes, in laboratory freezers.

Food-grade vegetable glycerin is 99.7% pure, with the remaining 0.3% being water. It has a sweet taste, but is metabolized differently than sugar and does not raise blood sugar levels. Glycerin is used in foods marketed as being low in carbohydrates to keep them sweet and moist. It also does not contribute to bacterial tooth decay.

Vegetable glycerin is also used as a substitute for alcohol, in making botanical extracts. The advantage of this is that people who do not want to be exposed to alcohol can still have access to the botanical products. The disadvantage is that the resulting products have a much shorter shelf life.

Its solubility in alcohol and water had led to great utility in the manufacturing of products. Glycerin is used in a large number of cosmetic and household products, such as toothpastes and shampoo. It is also a component of glycerin soap, which is often used by people with sensitive skin. This soap acts as moisturizer to prevent the skin from drying out. For this reason, glycerin lotion is also popular.

There are also medical uses for vegetable glycerin. Glycerin suppositories are used as laxatives. It can also be used as a topical remedy for a number of skin problems, including psoriasis, rashes, burns, bedsores, and cuts. Glycerin is also employed to treat gum disease, as it kills associated bacterial colonies.

While glycerin can be made as a by-product of soap that is made from animal fats, it can also be made from plants. The glycerol backbone is part of the basic structure of many lipids. Vegetable glycerin is made from the oils and fats of a plant-based ingredient, generally coconut or palm oil. The oil is heated to a high temperature under pressure with water. The glycerin backbone splits off from the fatty acids, and is absorbed by the water, from which it is then isolated and distilled.

How Much Is a Kilowatt Hour

A kilowatt hour a unit of energy, and the typical way that electricity is measured. A kilowatt (kW) is 1,000 watts (w), and a kilowatt hour refers to the use of a device or a set of devices that use 1,000 watts for one hour. Using a 100 watt light-bulb for 10 hours would equal 1 kilowatt hour (kWh), as would the use of a 10,000 watt machine for 6 minutes.

Kilowatts and Kilowatt Hours

A watt or kilowatt is a measure of power, or how much electricity is being used by a device at a particular moment. This is useful information, because it can be used to compare average energy consumption; an 11 watt compact fluorescent light (CFL) bulb might produce the same amount of light as a 100 watt incandescent bulb, making it more efficient. Like knowing the average miles per gallon (or kilometers per liter) that a car gets, the devices can be compared without taking how long they are being used into account.

Energy is a measurement of power over some period of time. Power companies use the kilowatt hour because power use is cumulative; someone who uses an 11 watt CFL isn't paying for the 11 watts that the bulb uses in any given instant, but rather how much power is used by that bulb over a month. To determine this cost, how many kilowatts a device uses is multiplied by how many hours it is used to get kWh, which are then multiplied by the price of electricity per kWh.

watts ÷ 1,000 = kWh
kWh × hours of operation × rate = cost

Electricity Rates

Electricity prices are measured by the kilowatt hour, and the rate tends to fluctuate over time — both over the long-term, as in a week or month, but also over the course of a single day at the wholesale level. In some countries and regions, prices for electricity can vary based on the time of day in which the power is used; in many other places, however, prices are set by the government or based on the average cost over time. Smart meter technology and "time-of-use" pricing is expected to become more widespread over time, however.

Prices also vary dramatically by region, often based on how much it costs to generate and distribute power, as well as taxes and other charges. In the United States for example, the average residential cost of a kilowatt hour in Wyoming is 6.2 cents and goes all the way up to 25.12 cents in Hawaii.

Electricity Rates in the US

Here are the costs per kilowatt hour by region of the United States in 2010:

Region	Average Residential Cost of a Kilowatt Hour
U.S. average	9.83
Pacific Noncontiguous	19.94
New England	14.44
Middle Atlantic	13.80
South Atlantic	10.08
East North Central	9.12
Pacific Contiguous	9.07
East South Central	8.20
West South Central	8.00
Mountain	7.84
West North Central	7.80

Region Definitions:

1. Pacific Noncontiguous: Alaska, Hawaii
2. New England: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont
3. Middle Atlantic: New Jersey, New York, Pennsylvania
4. South Atlantic: Delaware, District of Columbia, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia
5. East North Central: Illinois, Indiana, Michigan, Ohio, Wisconsin
6. Pacific Contiguous: California, Oregon, Washington
7. East South Central: Alabama, Kentucky, Mississippi, Tennessee
8. West South Central: Arkansas, Louisiana, Oklahoma, Texas
9. Mountain: Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, Wyoming
10. West North Central: Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota