This Day in Science History

yevaud · Apr 2, 2006

April 2 People Paul Joseph Cohen Born 2 Apr 1934 American mathematician who was awarded the Fields Medal in 1966 for his proof of the independence of the continuum hypothesis from the other axioms of set theory. Francesco Maria Grimaldi Born 2 Apr 1618; died 1663. Italian physicist who studied the diffraction of light. In Physico-mathesis of Lumine, coloribus and iride (1665) he wrote Lumen propagatur seu diffunditur not solum Direct, Refracte, ac Refexe, sed etiam Quatro modo, Diffracts. In a dark room, he let a beam of sunlight from a tiny opening in a black curtain pass through a fine screen (or a slit, an edge of screen, wire, hair, fabric or feathers of birds). Each time he observed the image on a screen, it was different from the normal geometrical shadow and had iridescent fringes. He applied the name diffraction for this change of trajectory of the light passing near opaque objects. More correctly, however, it may have been interferences with two close sources that Grimaldi probably observed. Hannes Alfven Died 2 Apr 1995 (born 30 May 1908) Hannes Olof Gösta Alfvén was a Swedish astrophysicist, one of the founders of the field of plasma physics (the study of ionized gases) and winner, with Louis Néel of France, of the 1970 Nobel Prize for Physics "for fundamental work in magnetohydrodynamics with fruitful applications in different parts of plasma physics." He was an early supporter of "plasma cosmology," a concept that challenges the big-bang model of the origin of the universe. Those who support the theory of plasma cosmology hold that the universe had no beginning (and has no forseeable end) and that plasma, with its electric and magnetic forces, has done more to organize matter in the universe into star systems and other large observed structures than has the force of gravity.<</safety_wrapper> <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 3, 2006

April 3 People Ralph A. Bagnold Born 3 Apr 1896; died 28 May 1990. English geologist who was a leading authority on the mechanics of sediment transport and on eolian (wind-effect) processes. While a career soldier, serving in Egypt prior to WW II, he first studied sand dune formation and movement. After retiring from the army (1935), he continued his research and wrote the book Physics of Blown Sand and Desert Dunes, investigating the physics of particles moving through the atmosphere and deposited by wind. He recognized two basic dune types, the crescentic dune, which he called "barchan," and the linear dune, which he called longitudinal or "sief" (Arabic for "sword"). During WW II, his avocational interest in vehicle performance on blowing sand aided the Allies in North Africa. Hermann Karl Vogel Born 3 Apr 1842; died 13 Aug 1907. German astronomer who discovered spectroscopic binaries (double-star systems that are too close for the individual stars to be discerned by any telescope but, through the analysis of their light, have been found to be two individual stars rapidly revolving around one another). He pioneered the study of light from distant stars, and introduced the use of photography in this field. Charles Wilkes Born 3 Apr 1798; died 8 Feb 1877. American oceanographer, who led the first major ocean expedition (1838-42), which circled the globe, and determined that Antarctica (which Wilkes so named) is a continent. Sir Edward Bullard Died 3 Apr 1980 (born 21 Sep 1907) English marine geophysicist noted for his work in geomagnetism who made the first satisfactory measurements of geothermal heat-flow through the oceanic crust. In early work, he measured minute gravitational variations by timing the swings of an invariant pendulum, which he used <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 4, 2006

April 4 People Shing-Tung Yau Born 4 Apr 1949 Chinese-born mathematician who was awarded the Fields Medal in 1983 for his work in partial differential equations and differential geometry. His work also has applications in topology, algebraic geometry, representation theory and general relativity. Working collaboratively with Richard M. Schoen, Yau solved a long-standing open problem in relativity theory, by showing the positivity of mass for space-time. As a consequence, Schoen and Yau were able to give the first rigorous demonstration of how black holes can be formed because of the condensation of matter. A black hole possesses a gravitational field so intense that no matter or radiation can escape from it. Yau was the 1997 National Medal of Science winner. Benjamin Peirce Born 4 Apr 1809; died 6 Oct 1880. American astronomer, mathematician and educator who computed the general perturbations of the planets Uranus and Neptune. He was Harvard's Perkins Professor of Astronomy and Mathematics for nearly 40 years, and was largely responsible for introducing mathematics as a subject for research in American institutions. He is known especially for his contributions to analytic mechanics and linear associative algebra, but he is also remembered for his early work in astronomy and for playing a role in the discovery of Neptune. Joseph-Nicholas Delisle Born 4 Apr 1688; died 11 Sep 1768. French astronomer who proposed that the series of coloured rings sometimes observed around the Sun is caused by diffraction of sunlight through water droplets in a cloud. He also worked to find the distance of the Sun from the Earth by observing transits of Venus and Mercury across the face of the Sun. Milan Stefanik Died 4 Apr 1919 (born 21 Jul 1880) Milan (Rastislav) Stef <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 5, 2006

April 5 People Ivar Giaver Born 5 Apr 1929 Norwegian-born American physicist who, for his experimental discoveries regarding tunneling phenomena in superconductors, shared the Nobel Prize for Physics in 1973 with Leo Esaki and Brian Josephson for work in solid-state physics. Giaever demonstrated (1960) the tunneling of electrons through a sandwich with an extremely thin oxide layer surrounded with metal either in superconducting state on both sides or in superconducting state on one side and in normal state on the other side. This gave direct evidence for the so called energy gap in a superconductor (predicted by Bardeen et al., in 1972). Later, Giaever developed the method into a very powerful and accurate spectroscopy to study the detailed properties of superconductors. Lawrence Dale Bell Born 5 Apr 1894; died 20 Oct 1956. U.S. aircraft designer, founder of Bell Aircraft Co., whose experimental X-1 rocket-propelled airplane in 1947 was the first to break the sound barrier in level flight. This firm also produced such significant aviation contributions as the nation's first jet propelled airplane, the world's first commercial helicopter, the world's fastest and highest flying airplane, the Bell X-1A, and the first jet vertical take-off and landing plane. Vincenzo Viviani Born 5 Apr 1622; died 22 Sep 1703. Italian mathematician, leading geometer of his time, who founded the Accademia del Cimento. As one of the first important scientific societies, this organization came before England's Royal Society. In 1639, at age 17, he became the student, secretary and assistant of Galileo (now blind) in Arcetri, until Galileo died in 1642. During his long career, Viviani published a number of books on mathematical and scientific subjects. He edited the first edition of Galileo's collected works (165 <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 6, 2006

April 6 People Horst L. Stormer Born 6 Apr 1949 Horst Ludwig Störmer is a German-born American physicist who shared (with Daniel C. Tsui and Robert B. Laughlin) the 1998 Nobel Prize in Physics for the discovery "of a new form of quantum fluid with fractionally charged excitations." By experiment using extremely powerful magnetic fields and low temperatures, in 1982, Störmer and Tsui found that electrons acting together in strong magnetic fields can form new types of "particles", with charges that are fractions of electron charges. Within a year. Laughlin made a theoretical analysis explaining their result. Harold E. “Doc” Edgerton Born 6 Apr 1903; died 4 Jan 1990. American electrical engineer and ultra-high-speed photographer. As a graduate at the Massachusetts Institute of Technology (1926), he used a strobe light in his studies. By 1931, he applied the strobe to ultra-high-speed photography. He formed a company (1947) to specialize in electronic technology, which led to inventing the Rapatronic camera, capable of photographing US nuclear bomb test explosions from a distance of 7 miles. Throughout his career he applied high-speed photography as a tool in various scientific applications. He also developed sonar to study the ocean floor. Using side-scan sonar, in 1973, he helped locate the sunken Civil War battleship USS Monitor, lost since 1862, off Cape Hatteras, NC. Donald Douglas Born 6 Apr 1892; died 1 Feb 1981. Donald (Wills) Douglas was an American aircraft designer whose the Douglas Aircraft Company produced military and civil aircraft. He graduating from the Massachusetts Institute of Technology as its first aeronautics student (1914), then consulted and designed for others until he founded his own business (1920). Over the years his company set the industry standard for reliability <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 7, 2006

April 7 People James Glaisher Born 7 Apr 1809; died 7 Feb 1903. English meteorologist and aeronaut. Between 1862-66, mostly with Henry Tracey Coxwell, he made balloon ascents, many of which were arranged by a committee of the British Association. The object was to carry out scientific observations such as the variation in temperature and humidity of the atmosphere at high elevations. On 5 Sep 1862, ascending from Wolverhampton, Glaisher and his companion attained the greatest height that had then been reached by a balloon carrying passengers. The precise altitude at the highest point is unknown because Glaisher lost consciousness and was unable to read the barometer, but estimated at 7 miles high. He produced dew-point tables (1847) and wrote several scientific books including Travels in the Air. Jacques-Alexandre-Cesar Charles Died 7 Apr 1823 (born 12 Nov 1746) French mathematician, physicist, and inventor. When Benjamin Franklin visited France in 1779, Charles was inspired to study physics. He soon became an eloquent speaker to non-scientific audiences. His lectures and demonstrations attracted notable patrons and helped popularize Franklin's theory of electricity and other new scientific concepts. With Nicolas and Anne-Jean Robert, he made several balloon ascents, and was the first to use hydrogen for balloon inflation (1783). Charles invented most of the equipment that is still used in today's balloons. About 1787 he developed Charles's law concerning the thermal expansion of gases that for a gas at constant pressure, its volume is directly proportional to its absolute temperature. Events Mars Odyssey In 2000, NASA launched the 2001 Mars Odyssey spacecraft on a Delta 2 rocket. Stunning images were sent back by the rocket's TV cameras during its fiery <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

alokmohan · Apr 7, 2006

Obscure names.

yevaud · Apr 8, 2006

April 8 People David Rittenhouse Born 8 Apr 1732; died 26 June 1796. American astronomer, instrument maker and inventor who was an early observer of the atmosphere of Venus. For observations for the transit of Venus on 3 Jun 1769, he constructed a high precision pendulum clock, an astronomical quadrant, an equal altitude instrument, and an astronomical transit. He was the first one in America to put spider web as cross-hairs in the focus of his telescope. He is generally credited with inventing the vernier compass and possibly the automatic needle lifter. He was professor of astronomy at the University of Pennsylvania. Benjamin Franklin consulted him on various occasions. For Thomas Jefferson he standardized the foot by pendulum measurements in a project to establish a decimal system of weights and measures. Pyotr Leonidovich Kapitsa Died 8 Apr 1984 (born 8 Jul 1894) Russian physicist who was a corecipient of the 1978 Nobel Prize for Physics for his basic strong magnetic field inventions and discoveries in the area of low-temperature physics. He discovered that helium II (the stable form of liquid helium below 2.174 K, or -270.976 C) has almost no viscosity (i.e., resistance to flow). Late in the 1940's Kapitza changed his focus, inventing high power microwave generators - planotron and nigotron (1950-1955) and discovered a new kind of continuous high pressure plasma discharge with electron temperatures over a million kelvin. Harold Delos Babcock Died 8 Apr 1968 (born 24 Jan 1882) American astronomer who with his son, Horace, invented the solar magnetograph (1951), for detailed observation of the Sun's magnetic field. With their magnetograph the Babcocks measured the distribution of magnetic fields over the solar surface to unprecedented precision and discovered magnetically variable stars. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

lampblack · Apr 8, 2006

In 1885, Granville T. Woods, a prolific black American inventor, patented an "Apparatus for Transmission of Messages by Electricity," No. 315,368. In the following years he introduced numerous innovations for use on railroads, applying electricity for telegraphy, brakes, overhead conductors, controls and an electric railway. Now here is an interesting man. Not much formal education but brilliant -- and he apparently was recognized for his accomplishments while still alive. This surprises me somewhat -- in a good way. Here's more about him: http://en.wikipedia.org/wiki/Granville_Woods <div class="Discussion_UserSignature"> Just tell the truth and let the chips fall... </div>

yevaud · Apr 9, 2006

April 9 People J. Presper Eckert, Jr. Born 9 Apr 1919; died 3 Jun 1995. J(ohn) Presper Eckert, Jr. was an American engineer and coinventor of the first general-purpose electronic computer, a digital machine that was the prototype for most computers in use today. In 1946, Eckert with John W. Mauchly fulfilled a government contract to build a digital computer to be used by the U.S. Army for military calculations. They named it ENIAC for Electronic Numerical Integrator and Computer. By 1949, they had started a manufacturing company for their BINAC computer. This was followed by a business oriented computer, UNIVAC (1951), which was put to many uses and spurred the growth of the computer industry. By 1966 Eckert held 85 patents, mostly for electronic inventions. James S. McDonnell Born 9 Apr 1899; died 22 Aug 1980. James S. McDonnell was an American manufacturer of aircraft McDonnell started his first company in 1928, to build the single Doodlebug, but since it found no market, he spent the next 10 years working for several aircraft companies. Then he founded the St. Louis based McDonnell Aircraft Co.on 6 Jul 1939. Among his notable achievements were the production of the U.S. Navy's first carrier based jet fighter (1946), the FM-1; Mercury, America's first manned space craft to orbit the earth (1962), and the F-4 Phantom jet. Elie-Joseph Cartan Born 9 Apr 1869; died 6 May 1951. French mathematician who greatly developed the theory of Lie groups and contributed to the theory of subalgebras. By 1904 Cartan was turning to papers on differential equations and from 1916 on he published mainly on differential geometry. Cartan also published work on relativity and the theory of spinors. He is certainly one of the most important mathematicians of the first half of the 20th century. Charles-Eu <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 10, 2006

April 10 People Sir John Leslie Born 10 Apr 1766; died 3 Nov 1832. Scottish physicist and mathematician who first created artificial ice. His practical scientific investigations led to his book Experimental Inquiry Into the Nature and Propagation of Heat (1804), dealing with the fundamental laws of heat radiation. Leslie gave the first correct description of capillary action (1802) and invented many instruments, most notably an accurate differential air thermometer, and also a hygrometer, a photometer, the pyroscope, atmometer and aethrioscope. In 1810, he devised a method of obtaining very low temperatures, by evaporating water in a receiver evacuated with an air-pump but containing a drying agent. His mathematical works include texts on geometry, trigonometry and The Philosophy of Arithmetic. Martin Swarzschild Died 10 Apr 1997 (born 31 May 1912) German-born American astronomer who in 1957 introduced the use of high-altitude hot-air balloons to carry scientific instruments and photographic equipment into the stratosphere for solar research. Auguste Lumiere Died 10 Apr 1954 (born 19 Oct 1862) Frenchman who, with his brother Louis, invented and pioneered the manufacturing of photographic equipment. They devised an early motion-picture camera and projector called the Cinématographe ("cinema" is derived from this name). Their film La Sortie des ouvriers de l'usine Lumière ("Workers Leaving the Lumière Factory"), is considered the first motion picture. In 1895, an invited audience at 44 Rue de Rennes in Paris, France, viewed the film they shot specially for the occasion showing workers leaving the Lumières' own factory in Lyon, which made all kinds of photographic products. The workers streamed out, most to foot, some with their bicycles, then followed by those with cars. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 11, 2006

April 11 People Sir Frank Whittle Born 11 Apr 1907; died 8 Aug 1996. English aviation engineer and pilot who was a pioneer in the field of jet propulsion, which he used to develop aircraft that could fly at faster speeds and higher altitudes than piston-engine propeller airplanes of the 1920s. While he was at Cranwell, still only 21 years of age, Whittle began to consider the possibilities of jet propulsion as applied to aircraft. By 1930, he had designed and patented a jet aircraft engine. After 11 years, Whittle's engine, tested and modified, successfully powered a Gloster-Whittle E.28/39, on a historic 17-min flight on 15 May 1941. Design work continued, and by the end of WW II, the Gloster Meteor became the RAF's first jet fighter that would fly 200-mph faster than the RAF's Spitfires and Hurricanes. Donald Menzel Born 11 Apr 1901; died 14 Dec 1976. Donald H(oward) Menzel was an American astronomer best known for his arguments against the existance of extraterrestrial UFO's. Menzel was one of the first practitioners of theoretical astrophysics in the United States and pioneered the application of quantum mechanics to astronomical spectroscopy. An authority on the sun's chromosphere, he discovered with J. C. Boyce (1933) that the sun's corona contains oxygen. With W. W. Salisbury he made (1941) the first of the calculations that led to radio contact with the moon in 1946. He supervised the assignment of names to newly discovered lunar features. Edward Charles Titchmarsh Born 11 Apr 1899; died 18 Jan 1963. English mathematician whose contributions to analysis placed him in the forefront of his profession. His contributions helped resolve the differences between the general theory of quantum mechanics and the methods used to solve particular problems in quantum theory. All Titchmarsh's wor <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 12, 2006

April 12 People Albert Heim Born 12 Apr 1849; died 31 Aug 1937. Swiss geologist whose studies of the Swiss Alps greatly advanced knowledge of the dynamics of mountain building and of glacial effects on topography and geology. He studied the formation of overthrusts and nappes in the Alps. He supported the idea of a contracting Earth. He also studied the mechanics of rock deformation, proposing that rocks can deform plastically under pressure and that the same pressure causes metamorphism. After a near-fatal fall in the Alps during which he had a mystical experience, Heim began the first serious study of near-death experiences. Over a period of several decades he collected observations and accounts from numerous survivors of serious accidents. Heim first presented these findings at the Swiss Alpine Club in 1892. Igor Yevgenyevich Temm Died 12 Apr 1971 (born 8 July 1895) Soviet physicist who shared the 1958 Nobel Prize for Physics with Pavel A. Cherenkov and Ilya M. Frank for his efforts in explaining Cherenkov radiation. Tamm was an outstanding theoretical physicist, after early researches in crystallo-optics, he evolved a method for interpreting the interaction of nuclear particles. Together with I. M. Frank, he developed the theoretical interpretation of the radiation of electrons moving through matter faster than the speed of light (the Cerenkov effect), and the theory of showers in cosmic rays. He has also contributed towards methods for the control of thermonuclear reactions. Ferdinand Von Lindemann Born 12 Apr 1852; died 6 March 1939. (Carl Louis) Ferdinand von Lindemann was a German mathematician who was the first to prove that is transcendental (it is not a solution of any algebraic equation with rational coefficients). This finally established the insoluble nature of the classical G <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 13, 2006

April 13 People Stanislaw M. Ulam Born 13 Apr 1909; died 13 May 1984. Polish-American mathematician who played a major role in the development of the hydrogen bomb at Los Alamos. He solved the problem of how to initiate fusion in the hydrogen bomb by suggesting that compression was essential to explosion and that shock waves from a fission bomb could produce the compression needed. He further suggested that careful design could focus mechanical shock waves in such a way that they would promote rapid burning of the fusion fuel. Ulam, with J.C. Everett, also proposed the "Orion" plan for nuclear propulsion of space vehicles. While Ulam was at Los Alamos, he developed "Monte-Carlo method" which searched for solutions to mathematical problems using a statistical sampling method with random numbers. Bruno Rossi Born 13 Apr 1905; died 21 Nov 1993. Italian pioneer in the study of cosmic radiation. In the 1930s, his experimental investigations of cosmic rays and their interactions with matter laid the foundation for high energy particle physics. Cosmic rays are atomic particles that enter earth's atmosphere from outer space at speeds approaching that of light, bombarding atmospheric atoms to produce mesons as well as secondary particles possessing some of the original energy. He was one of the first to use rockets to study cosmic rays above the Earth's atmosphere. Finding X-rays from space he became the grandfather of high energy astrophysics, being largely responsible for starting X-ray astronomy, as well as the study of interplanetary plasma. Sir Robert Alexander Watson-Watt Born 13 Apr 1892; died 5 Dec 1973. Physicist, born in Brechin, Scotland, credited with the development of radar location of aircraft, in England. He studied at St Andrews University, taught at Dundee University, and in 1917 wo <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 13, 2006

April 14 People Reinout Willem Van Bemmelen Born 14 Apr 1904; died 1983. Dutch geologist whose studies of the regional geology of Indonesia led to recognition of the importance of island areas in the development of the Earth's crust. Long before others even thought about compiling an article on this archipelagos, he published his biggest contribution, the Geology of Indonesia (1949). Still often cited, this book covers broad aspects of the regional geology of Indonesia, which is prolific in terms of hydrocarbon and other mineral resources. Indonesia is part of the volcanic "ring of fire" and one of the most complex geological settings in the world because it lies at the junction of three major tectonic plates (Pacific, Indian-Australian, and Eurasian). He also researched continental drift and the winds of the equatorial stratosphere. Christiaan Huygens Born 14 Apr 1629; died 8 Jul 1695. Dutch mathematician, astronomer, and physicist, who founded the wave theory of light, discovered the true shape of the rings of Saturn, and made original contributions to the science of dynamics - the study of the action of forces on bodies. Using a lens he ground for himself, Huygens detected, in 1655, the first moon of Saturn. In 1656 he patented the first pendulum clock, which he developed to meet the need for an exact measure of time while observing the heavens. Huygens studied the relation of the length of a pendulum to its period of oscillation (1673). This lead him to formulate theories on the centrifugal force in circular motion which would influence Sir Isaac Newton in formulating his Law of Gravity. Huygens also studied and drew the first maps of Mars. (Amalie) Emmy Noether Died 14 Apr 1935 (born 23 Mar 1882) (Amalie) Emmy Noether was a German mathematician best known for her contributions to abstrac <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 15, 2006

April 15 People Robert L. Mills Born 15 Apr 1927; died 27 Oct 1999. American physicist who shared the 1980 Rumford Premium Prize with his colleague Chen Ning Yang for their "development of a generalized gauge invariant field theory" in 1954. They proposed a tensor equation for what are now called Yang-Mills fields. Their mathematical work was aimed at understanding the strong interaction holding together nucleons in atomic nuclei. They constructed a more generalized view of electromagnetism, thus Maxwell's Equations can be derived as a special case from their tensor equation. Quantum Yang-Mills theory is now the foundation of most of elementary particle theory, and its predictions have been tested at many experimental laboratories. Samuel Kurtz Hoffman Born 15 Apr 1902 American propulsion engineer who led U.S. efforts to develop rocket engines for space vehicles. Emory Lee Chaffee Born 15 Apr 1885; died 8 Mar 1975. U.S. physicist known for his work on thermionic vacuum (electron) tubes. Johannes Stark Born 15 Apr 1874; died 21 Jun 1957. German physicist who won the 1919 Nobel Prize for Physics for his discovery in 1913 that an electric field would cause splitting of the lines in the spectrum of light emitted by a luminous substance; the phenomenon is called the Stark effect. Friedrich Georg Wilhelm Von Struve Born 15 Apr 1793; died 23 Nov 1864. German-Russian astronomer, one of the greatest 19th-century astronomers and the first in a line of four generations of distinguished astronomers. He founded the modern study of binary (double) stars. In 1817, he became director of the Dorpat Observatory, which he equipped with a 9.5-inch (24-cm) refractor that he used in a massive survey of binary stars from the north <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 16, 2006

April 16 People Wilbur Wright Born 16 Apr 1867; died 30 May 1912. American aviation pioneer, who with his brother Orville, invented the first powered airplane, Flyer, capable of sustained, controlled flight (17 Dec 1903). Orville made the first flight, airborn for 12-sec. Wilbur took the second flight, covering 853-ft (260-m) in 59 seconds. By 1905, they had improved the design, built and and made several long flights in Flyer III, which was the first fully practical airplane (1905), able to fly up to 38-min and travel 24 miles (39-km). Their Model A was produced in 1908, capable of flight for over two hours of flight. They sold considerable numbers, but European designers became strong competitors. After Wilbur died of typhoid in 1912, Orville sold his interest in the Wright Company in 1915. John Hadley Born 16 Apr 1682; died 14 Feb 1744 British mathematician and inventor who improved the reflecting telescope, producing the first such instrument of sufficient accuracy and power to be useful in astronomy. George William Hill Died 16 Apr 1914 (born 3 Mar 1838) U.S. mathematical astronomer considered by many of his peers to be the greatest master of celestial mechanics of his time. After receiving a B.A. from Rutgers College (1859), Hill joined the Nautical Almanac Office in 1861. Among his many accomplishments, Hill was the first to use infinite determinants to analyze the motion of the Moon's perigee (1877). He also developed a theory of the motion of Jupiter and Saturn. His most significant theory, dealing with the effects of the planets on the Moon's motion, is considered fundamental in the development of celestial mechanics. Henry Augustus Rowland Died 16 Apr 1901 (born 27 Nov 1848) American physicist who invented the concave diffraction grating, <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 17, 2006

April 17 People Augustus Edward Hough Love Born 17 Apr 1863; died 5 Jun1940. British geophysicist and mathematician who discovered a major type of earthquake wave that was subsequently named for him. Love assumed that the Earth consists of concentric layers that differ in density and postulated the occurrence of a seismic wave confined to the surface layer (crust) of the Earth which propagated between the crust and underlying mantle. His prediction was confirmed by recordings of the behaviour of waves in the surface layer of the Earth. He proposed a method, based on measurements of Love waves, to measure the thickness of the Earth's crust. In addition to his work on geophysical theory, Love studied elasticity and wrote A Treatise on the Mathematical Theory of Elasticity, 2 vol. (1892-93). William John McGee Born 17 Apr 1853; died 4 Sep 1912. American geologist, hydrologist, archaeologist who was noted for his pioneer studies documenting the occurrence of waves of invasions and recessions of ice sheets in North America, thus establishing the complexity of the Great Ice Age. He worked in a number of governmental capacities, including as a director in the U.S. Geological Survey, and was a founder and president of the National Geographic Society. While on the staff of the Bureau of Soils, he organized the landmarkConference of Governors on Conservation of Natural Resources (13-15 May 1908) and has been called the "chief theorist of the conservation movement." As an anthropologist he studied the American Indians and wrote The Seri Indians (1898). Giovanni Riccioli Born 17 Apr 1598; died 25 June 1671. Italian astronomer who was the first to observe (1650) a double star (two stars so close together that they appear to be one) - Mizar in Ursa Major, the middle star in the handle of the Big Dipper. H <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 18, 2006

April 18 People Maurice Goldhaber Born 18 Apr 1911 U.S. physicist whose contributions to nuclear physics include the discovery that the nucleus of the deuterium atom consists of a proton and a neutron. H.L. Callender Born 18 Apr 1863; died 21 Jan 1930. H(ugh) L(ongbourne) Callendar was a British physicist who made notable contributions to thermometry, calorimetry, and knowledge of the thermodynamic properties of steam. Callendar in 1886 described a precise thermometer based on the electrical resistivity of platinum; since then, platinum resistance thermometers have been prescribed for the determination of temperatures between the defined points of internationally recognized temperature scales. Later he developed the electrical continuous-flow calorimeter, which measures the heat-carrying properties of liquids. Paul-Emile Lecoq De Boisbaudran Born 18 Apr 1838; died 28 May 1912. French chemist who developed improved spectroscopic methods which had recently been developed by Kirchhoff. In 1859, he set out to scan minerals for unknown spectral lines. Fifteen years of persistence paid off when he discovered the elements gallium (1875), samarium (1880), and dysprosium (1886). He ranks with Bunsen, Kirchoff and Crookes as one of the founders of the science of spectroscopy. Guided by the general arrangement of spectral lines for elements in the same family, he believed the element he called gallium (in honour of France) was the eka-aluminium predicted by Mendeléeff between aluminium and indium. Since it is liquid between about 30 - 1700 deg C, a gallium in quartz thermometer can measure high temperatures. Albert Einstein Died 18 Apr 1955 (born 14 Mar 1879) German-American physicist who developed the special and general theories of relativity and won the Nobel <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 19, 2006

April 19 People Richard Von Mises Born 19 Apr 1883; died 14 Jul 1953. Austrian-American mathematician and aerodynamicist who notably advanced statistics and the theory of probability. Von Mises' contributions range widely, also including fluid mechanics, aerodynamics, and aeronautics. His early work centred on aerodynamics. He investigated turbulence, making fundamental advances in boundary-layer-flow theory and airfoil design. Much of his work involved numerical methods and this led him to develop new techniques in numerical analysis. He introduced a stress tensor which was used in the study of the strength of materials.Von Mises' primary work in statistics concerned the theory of measure and applied mathematics. His most famous, yet controversial, work was in probability theory. Albert Wallace Hull Born 19 Apr 1880; died 22 Jan 1966. American physicist who independently discovered the powder method of X-ray analysis of crystals (1917), which permits the study of crystalline materials in a finely divided microcrystalline, or powder, state. His first work was on electron tubes, X-ray crystallography, and (during WW II) piezoelectricity. In the 1920's, he studied noise measurements in diodes and triodes. In the 1930's, he also took interest in metallurgy and glass science. His best-known work was done after the war, especially his classic paper on the effect of a uniform magnetic field on the motion of electrons between coaxial cylinders. He also invented the magnetron (1921) and the thyratron (1927), and other electron tubes with wide application as components in electronic circuits. Charles Sanders Peirce Died 19 Apr 1914 (born 10 Sep 1839) American scientist, logician, and philosopher who is noted for his work on the logic of relations and on pragmatism as a method of research. He was the f <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 20, 2006

April 20 People Gerald S. Hawkins Born 20 Apr 1928; died 26 May 2003. Gerald Stanley Hawkins was an English astronomer and mathematician who identified Stonehenge to be a prehistoric astronomical observatory. He identified 165 key points in the Stonehenge complex and found that many of them very strongly correlated with the rising and setting positions of the sun and moon. He used a computer to show that there existed at Stonehenge a pattern of alignments with twelve major lunar and solar events. He first published his findings in an article, Stonehenge Decoded, in the journal Nature (1963), and then in a book with the same title (1965). In Beyond Stonehenge he explored the mysteries of Machu Pichu, the Nasca Lines, Easter Island and the Egyptian Temples of Karnak and Amon-Ra. Karl Alex Muller Born 20 Apr 1927 Swiss physicist who, along with J. Georg Bednorz, was awarded the 1987 Nobel Prize for Physics for their joint discovery of superconductivity in certain substances at higher temperatures than had previously been thought attainable. They startled the world by reporting superconductivity in a layered, ceramic material at a then-record-high temperature of 33 degrees above absolute zero. Their discovery set new research worldwide into related materials that yielded dozens of new superconductors, eventually reaching a transition temperature of 135 kelvin. Kai Manne Borje Siegbahn Born 20 Apr 1918 Swedish physicist, corecipient with Nicolaas Bloembergen and Arthur Leonard Schawlow of the United States of the 1981 Nobel Prize for Physics for their revolutionary work in spectroscopy, particularly the spectroscopic analysis of the interaction of electromagnetic radiation with matter. James David Forbes Born 20 Apr 1809; died 31 Dec 1868. Scottish physici <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 21, 2006

April 21 People Percy Williams Bridgman Born 21 Apr 1882; died 20 Aug 1961 American experimental physicist noted for his studies of materials at high temperatures and pressures.He was awarded the Nobel Prize for Physics in 1946 for his "invention of an apparatus to produce extremely high pressures, and for the discoveries he made therewith in the field of high pressure physics." He was the first Harvard physicist to receive a Nobel Prize in Physics. His first experimental work on static high pressures beginning in 1908 at first yielded pressures of about 6,500 atmospheres. Eventually, he reached about 400,000 atmospheres. During studies of the phase changes of solids under pressure, he discovered several high-pressure forms of ice. Bridgman also wrote eloquently on matters of general interest in the physics of his day. Jean-Baptiste Biot Born 21 Apr 1774; died 3 Feb 1862. French physicist who helped formulate the Biot-Savart law, which concerns magnetic fields, and laid the basis for saccharimetry, a useful technique of analyzing sugar solutions. Andre-Louis Danjon Died 21 Apr 1967 (born 6 Apr 1890) French astronomer who devised a now standard five-point scale for rating the darkness and colour of a total lunar eclipse, which is known as the Danjon Luminosity Scale. He studied Earth's rotation, and developed astronomical instruments, including a photometer to measure Earthshine - the brightness of a dark moon due to light reflected from Earth. It consisted of a telescope in which a prism split the Moon's image into two identical side-by-side images. By adjusting a diaphragm to dim one of the images until the sunlit portion had the same apparent brightness as the earthlit portion on the unadjusted image, he could quantify the diaphragm adjustment, and thus had a real measurement for the brigh <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

yevaud · Apr 22, 2006

April 22 People J. Robert Oppenheimer Born 22 Apr 1904; died 18 Feb 1967. J(ulius) Robert Oppenheimer was a U.S. theoretical physicist and science administrator, noted as director of the Los Alamos laboratory during development of the atomic bomb (1943-45) and as director of the Institute for Advanced Study, Princeton (1947-66). Accusations as to his loyalty and reliability as a security risk led to a government hearing that resulted the loss of his security clearance and of his position as adviser to the highest echelons of the U.S. government. The case became a cause célèbre in the world of science because of its implications concerning political and moral issues relating to the role of scientists in government. Sir Harold Jeffreys Born 22 Apr 1891; died 18 Mar 1989. English geophysicist, astronomer, and mathematician with diverse scientific interests. In astronomy he proposed models for the structures of the outer planets, and studied the origin of the solar system. He calculated the surface temperatures of gas at less than -100°C, contradicting then accepted views of red-hot temperatures, but Jeffreys was shown to be correct when direct observations were made. In geophysics he researched the circulation of the atmosphere and earthquakes. Analyzing earthquake waves (1926), he became the first to claim that the core of the Earth is molten fluid. Jeffreys also contributed to the general theory of dynamics, aerodynamics, relativity theory and plant ecology. Immanuel Kant Born 22 Apr 1724; died 12 Feb 1804. German philosopher, trained as a mathematician and physicist, who published his General History of Nature and theory of the Heavens in 1755. This physical view of the universe contained three anticipations of importance to astronomers. 1) He made the nebula hypothesis ahead of Laplace. 2) H <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

halcyondays · Apr 22, 2006

<<< In 1056, the supernova in the Crab nebula was last seen by the naked eye. />>> I am sure it was 1054.

telfrow · Apr 22, 2006

It was first seen by Chinese astronomers on July 4, 1054; it was visible in daylight for 23 days and visible in the night sky for 653 days. Link <div class="Discussion_UserSignature"> Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild. - Tennyson </div>

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