Genetic research

   In 1962 the Nobel Prize in medicine, the most honored scientific award in the world, was given to an American and two British scientists. What they had discovered, in the 1950's, was the structure of DNA (deoxyribonucleic acid), an essential component of genes. As you already know, genes are the small units of chromosomes that convey characteristics, such as color of hair and eyes, from parent to child. By understanding DNA, one can understand how a gene is structured—what scientists Call the "genetic code."
   By unraveling the genetic code, the experimenters with DNA came closer to explaining how different life forms are created. This break-through made possible new research into viruses, bacteria, human cells, and diseases such as cancer. Scientists found it possible to reproduce life forms in the laboratory. Major advances in treating illness were anticipated.

Sir William Ramsay

Sir William Ramsay (1852-1916) was a Scottish chemist who, with Baron Rayleigh, isolated the first rare atmospheric gas, argon. Ramsay also discovered the other inert gases: helium, neon, krypton, and xenon. For this work, he received the 1904 Nobel prize for chemistry. His explanation of me nature of these elements led to important ideas about atomic structure. The gases also have great practical importance.
Ramsay was born in Glasgow and studied in Germany at Heidelberg and Tübingen universities. He taught at Glasgow and Bristol, and at University College in London. He was knighted in 1902, and in 1911, he became president of the British Association for the Advancement of Science.

Supersonic phenomena

   Supersonics are a branch of physics dealing with the phenomena arising when a solid body exceeds the speed of sound in the medium in which it is traveling; usually the medium is air. The speed of sound in air is dependent upon several factors, including the temperature, humidity, density, and altitude. Because the speed of sound, being thus vari¬able, is a critical factor in aerodynamic equations, it is represented by a Mach number. The Mach number is the speed of the projectile or plane with reference to the ambient atmosphere, divided by the speed of sound in the same medium and under the same conditions. Thus, at sea level, under standard
conditions of humidity and temperature, a speed of about 760 miles per hour represents a Mach number of one, that is, M=l. The same speed in the stratosphere, because of difference in density and temperature, would correspond to a Mach number of M=1.16. By designating speeds by Mach number, rather than by feet per second, or miles per hour, it is possible to obtain a more accurate representation of the actual conditions encountered in flight.

Who was Leon Foucault?

Leon Foucault was a French physicist. Born Paris, France, Sept. 18, 1819. Died Paris, Feb. 11, 1868.
Foucault invented a type of pendulum, since named in his honor, which gives direct evidence of the rotation of the Earth. He also demonstrated the Earth's rotation by means of a gyroscope.
Some of Foucault's most important work was in the study of light. He improved the method of measuring the speed of light devised by the French physicist A. H. L. Fizeau. By means of this method he found that the speed of light is inversely proportional to the index of refraction of the medium through which the light is passing. His other discoveries included a polarizer for light and an improved method of making telescope mirrors. Foucault also studied the eddy currents, sometimes called Foucault currents, produced when a copper disk rotates in a magnetic field.
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Who was Heinrich Hertz?

Heinrich Hertz (1857-1894)

   Heinrich Hertz (1857-1894) was a noted German physicist. As a student at Berlin in 1880 he came under the influence of Helmholtz, which determined his later career. His work while here on the inertia exhibited by electricity was especially creditable. Two years were spent as a lecturer in physics at Kiel, then four years at Carlsruhe, when, in 1889, he became professor of physics at the University of Bonn. The year previous Hertz made known his immortal work on the relation between light and electricity which had been prophesied by Maxwell in his interpretation of the work of Faraday. In this Hertz demonstrated that electricity can be transmitted in elec¬tromagnetic waves with approximately the same velocity as light waves. This production and detection of electromagnetic waves by Hertz was the beginning of that experimentation which gave us wireless telegraphy and other electric wave phenomena.

   The hertz (Hz) was established in Hertz's honor in 1930 as a unit of measurement for frequency, a measurement of the number of times that a repeated event occurs per unit of time (also called "cycles per sec").

Who is known as the "French Newton"?

Laplace

French mathematician and astronomer Pierre-Simon Laplace (1749-1827) made several important contributions to science in general and astronomy in partic¬ular. Together with chemist Antoine-Laurent Lavoisier, Laplace founded the science of thermochemistry, the science dealing with the interrelationship of heat and chemical interactions. In addition, Laplace applied Newtonian calculus in his experiments with the forces acting be¬tween particles of ordinary matter, light, heat, and electricity. By examining their results, Laplace and his colleagues were able to determine equations explaining the re-fraction of light, the conduction of heat, the flexibility of solid objects, and the distribution of electricity on conductors. In the field of astronomy, Laplace was primarily interested in the movements of the moon and the planets. He studied their gravitational effect on one another and published his results over a twenty-five-year period beginning in 1799 in a five-volume book called Traite de Méchanique Celeste (Celestial Me¬chanics). Since his work expanded on the gravitational theories of Englishman Isaac Newton, Laplace earned the nickname "French Newton." Laplace also developed a theory of the formation of the solar system and, with a colleague, introduced the concept that led to the theory of black holes.

What is helium?

   Helium is a colorless, non-inflammable gas whose practical value was demonstrated in 1918, when American chemists discovered a method of producing it in quantity. Helium like nitrogen and argon, has prac¬tically no chemical activity. It is twice as heavy as hydrogen, the lightest known substance, and is now used in place of that gas for inflating balloons because it will not take fire. Helium is found in the atmos¬phere in proportion of 4 volumes of the element to 1,000,000 volumes of air. It is generally obtained from liquid air by distillation, but it can be separated from its compounds by the use of nitrogen or argon. It occurs in some minerals and is thought to be a product of the disintegration of radium.

Helium atom

What is vacuum?

Vacuum, a space that contains no matter. In the physical sense of the word a vacuum has never existed on the Earth, and its creation is thus far a practical impossibility. The space between the Earth's atmosphere and other astronomical bodies is believed to be a partial vacuum. The term vacuum is commonly used in describing a region of less than atmospheric pressure such as can be produced by exhausting vessels of air.
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What is Nitrogen?

  Nitrogen is an element found in plants, animals, air and other non-living compounds. About 78% of the atmosphere is made up of nitrogen gas. It is colorless, odorless and tasteless. Nitrogen (symbol N) is element number 7. Its atomic weight is 14.007 (14.008, O =16).
  Nitrogen gas is difficult to dissolve in water and does not combine readily with most elements. It is very essential for both plant life, which uses nitrogen to grow, and animal life, which uses nitrogen in very complicated structures called proteins.
  Nitrogen was first mentioned in writings by D. Rutherford in 1772. Later it was studied by Scheele and Lavoisier and at that time was called azote. The word nitro¬gen comes from the Greek word nitron or saltpeter, a common compound of nitrogen. Most of the supply of soluble nitrogen once came from saltpeter or potassium nitrate, KNO3.
  Nitrogen  turns  to  a  liquid  at  a temperature of about —196 °C, the boiling point of nitrogen.
  Nitrogen gas is quite inert and combines with other elements very slowly. The reason is that the atoms in the diatomic molecule of nitrogen, N2, have a very strong bond. However, when nitrogen does combine with other elements, it forms some of the most active compounds. For example, explosives such as nitroglycerin and trinitrotoluene, or TNT, are nitrogen compounds.

Some facts about the life of Sir Isaac Newton

Isaac Newton (1642-1727)

English mathematician and physicist Isaac Newton was considered to be one of the most intelligent people who ever lived. Newton articulated the law of universal gravitation and wrote one of the most important books about science of all time. Following a difficult childhood, Newton went at age nineteen to study at Trinity College, Cambridge. There he studied the works of Johannes Kepler, Rene Descartes, Galileo, and Copernicus. He graduated in 1665, the year the university closed due to an outbreak of bubonic plague, and returned to the family farm. Agricultural work left Newton plenty of time to think and to conduct experiments. He studied the rainbow created by light passed through a prism and realized that white light is really a combination of all the colors. He also invented calculus, a method of calculation by a system of algebraic notations—at the same time as, yet independent of, German philosopher Gottfried Leibniz. And it was in the period of farm life after college that Newton developed his famous universal theory of grav¬ity. Newton later returned to Cambridge to assume the Lucasian Professorship of Mathematics.
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Who was Gerard P. Kuiper?

  Gerard Peter Kuiper (Gerrit Pieter Kuiper), was a Dutch-American astronomer. Born in Tuitjenhorn (Harenkarspel), the Netherlands, Dec. 7. 1905.
  Kuiper, as director of the Lunar and Planetary Laboratory at the University of Arizona, headed the successful Ranger Moon program. In 1948 he detected carbon dioxide in the atmosphere of Mars and methane and ammonia on Titan, the largest satellite of Saturn in 1944. In the same year he discovered and named Miranda, the fifth sateilite of Uranus, and in 1949 he discov¬ered and named Nereid, the second satellite of Neptune. He also developed the protoplanet theory of the origin of the solar system.
  In the 1960s, Kuiper helped identify landing sites on the Moon for the Apollo program.
  Died in 1973 while on vacation with his wife in Mexico

What is the law of universal gravitation?

   English mathematician Isaac Newton combined his three laws of motion to come up with the law of universal gravitation. This law states that the gravitational force between any two objects depends on the mass of each object and the distance between them. The greater each object's mass, the stronger the pull, but the greater the distance between them, the weaker the pull. This relationship, known as an inverse square law, states that gravita¬tional force is equal to a gravitational constant times the mass of each object, divided by the square of the distance separating them.

Isaac Newton

Sir Alexander Fleming

Sir Alexander Fleming was a British bacteríologist. Born Lockfield, Scotland, Aug. 6, 1881. Died London, Eng¬land, Mar. 11, 1955.
Fleming was awarded a share of the 1945 Nobel Prize in physiology and medicine for his discovery of penicillin. In 1928, Fleming noticed that a mold, which had apparently come through a window of his laboratory, had contaminated a culture plate on which he was growing bacteria. Around the mold was a clear circle, where all the bacteria had been killed. Fleming identified the mold as Penicillium notatum and called the bacteria-killing substance it produced penicillin. Fleming later found that penicillin kills many kinds of bacteria and is nonpoisonous to humans. Fleming also discovered lysozyme, a substance in the body that can dissolve certain bacteria.

Who was James Hutton?

James Hutton (1726-1797)

  James Hutton was a Scottish geologist and physician, became famous for two theories on the origin of the Earth. He is called the father of modern geology.
  According to one of Hutton's theories, heat played an important part in the formation of the Earth. Hutton believed that rocks were formed from a molten mass. Most other scientists thought water had once covered the Earth and that rocks were formed when minerals settled at the bottom of the water.
  Hutton also theorized that the Earth had changed gradually by natural processes and would continue to change through the same processes. Other scientists believed the Earth was completely formed about 6,000 years ago and that only rare catastrophes could change its features.

Who was Hans Christian Oersted?

  Hans Christian Oersted was the Danish physicist and chemist who founded the branch of science called electromagnetism. Electromagnetism deals with magnetic fields developed by electricity.
  During an evening lecture at the University of Copenhagen where Oersted served as professor, he accidentally discovered that a magnetic needle was deflected by an electrical current. This discovery established him as one of the outstanding physicists of his age. After experimenting, Oersted discov¬ered that every conductor which carries an electrical current is surrounded by a magnetic field. This experiment, now known as the "Oersted Experiment," proved that electricity can produce magnetism. In 1934 the "Oersted" was adopted as the unit of
measurement of the strength of a magnetic field.

Thomas Henry Huxley

Thomas Henry Huxley (1825-1895) was a famous zoologist, lecturer, and writer. He was one of the first to be convinced by Charles Darwin's analysis of organic evolution, and he extended and defended it. Through his lectures, writings, and committees, Huxley helped advance scientific thought.
His writings include Evidence as to Man's Place in Nature (1863), Critiques and Addresses (1873), and A Manual of the Anatomy of Invertebrated Animals (1877). His essay "On a Piece of Chalk" (1868) and his essay demonstrating changes in the feet of fossil horses are outstanding.
Many of Huxley's expressions became famous. He introduced the word agnostic to describe one who believes that the existence of God or a spiritual world cannot be proved. He coined the word biogenesis to emphasize that life arises only from previous life.
Huxley was born near London, and studied by himself until he entered medical school. He became a surgeon in the British navy and spent four years in the Indian Ocean and East Indies. He wrote a pioneering account of jellyfishes, and returned to England to find that he had become famous as a zoologist. From 1854 to 1885, he taught natural history at the Royal School of Mines. He served as president of the Royal Society from 1881 to 1885.

George Simon Ohm

Georg Ohm (1797-1854)

  Georg Simon Ohm was a German physicist who is best known f or Ohm's Law of electric conduction. This law states that the current, I, that flows in a circuit multiplied by the amount of resistance, R, is equal to the applied voltage, E. The law may be stated in symbols as E = I x R. The ohm, the unit of electrical resistance, is named in his honor. He is also known for work in mathematics and acoustics.
   Ohm was born in Erlanger, Germany, on March 16, 1787. After attending the local university, he was, in 1817, appointed pro¬fessor of mathematics at the Jesuits' College at Cologne. He remained there until 1833 when he resigned to join the faculty of the Polytechnic School of Nuremberg. In 1849, he accepted an appointment as professor of mathematics at Munich. Ohm's numerous writings were of somewhat inferior quality. One exception was a pamphlet published in Berlin in 1827 which contained a summary of what is now known as Ohm's Law. His work was coldly received by his fellow scientists, and Georg Ohm was so deeply hurt that he resigned his position at the Jesuits' College, Cologne. His work began to be recognized, however, and in 1841 he was awarded the Copley Medal of the Royal Society in London. One year later he was made a foreign member of the Society.


What is the Ohm?
The ohm is the unit of resistance to the passage of an electric current. The ohm is the resistance causing a potential drop of one absolute volt when a steady current of one absolute ampere flows through it.

Christiaan Huygens

  Christiaan Huygens (1629-1695), was a Dutch mathematician, physicist, and astronomer, discovered the polarization of light, and investigated and developed the wave theory of light. He coined the word ether for the medium in which light waves were then assumed to travel. Huygens developed an improved method of grinding telescope lenses in 1655. He built the first powerful telescopes, which made possible his discovery of a satellite and ring of Saturn. He was the first to use a pendulum to regulate a clock. He also invented the micrometer, an instrument used to measure extremely small distances.
  Huygens was born at The Hague, The Netherlands. He studied law and mathematics at Leiden. In 1663, he became a member of The Royal Society, England's oldest scientific society. From 1666 to 1681, Huygens worked in París at the invitation of Ring Louis XIV of France.

Who was Augustin Jean Fresnel?

   Augustin Jean Fresnel was a French engineer and physicist, was born in Broglie, Normandy, and studied at the École Polytechnique and the École des Ponts et Chaussées. After spending several years as a government engineer in various parts of France, Fresnel lost his post because he declared his allegiance to the Bourbons when Napoleon escaped from Elba. Through the influence of Dominique Arago, he subsequently became secretary of the government's lighthouse department in Paris. There he invented the lighthouse lens which bears his name, introduced revolving lights, and designed the Fresnel concentric wick, which greatly enhanced the brilliancy of lighthouse lamps.
   Fresnel extended his researches to the kinematics and the dynamics of light and, independently of the investigations conducted by Thomas Young, discovered the phenomenon of interference, or effect caused by the meeting of two beams of monochromatic light. Fresnel insured acceptance of the undulatory theory of light when he introduced the idea that the vibrations of the ether are transverse to the directions of the beams of light.
   The validity of the undulatory theory was further confirmed by Fresnel's investigations of the modifications in interference brought about by polarized light.

How do we measure energy?

We measure energy by the amount of work it does. We measure it in foot-pounds. For example, 20 foot-pounds is the amount of energy it would take to lift 2 pounds 10 feet, or 10 pounds 2 feet, or 5 pounds 4 feet. We also measure energy in cal¬ories. A "small calorie," the kind people count when they are dieting, is a thousand times bigger — so a man on a strict diet might eat only enough food to give him 3,000,000 foot-pounds of energy a day. We also measure energy in joules, ergs, horsepower-hours, kilowatt-hours, and all sorts of units, depending on the kind of work we mean.