Nikola Tesla Crossword

February 24: Pulsar
In 1968, Nature carried the announcement of the discovery of pulsars (pulsating radio sources). The first pulsar was discovered by a graduate student, Jocelyn Bell, on November 28, 1967, then working under the direction of Prof. A. Hewish. This extraterrestrial pulsating radio source was observed at the Mullard Radio Astronomy Observatory, Cambridge University, England. They were using a special radio telescope, a large array of 2,048 aerials covering an area of 4.4 acres. The discovery of these fascinating objects opened new horizons in studies as diverse as quantum- degenerate fluids, relativistic gravity and interstellar magnetic fields. Under extraordinary physical conditions, radiation is generated and appears pulsed with a clock-like precision.

February 23: Aluminium isolated
In 1886, Charles M. Hall, a young U.S. chemist, completed his electrolytic process for the separation of aluminum from its ore, a mere eight months since he graduated from college. He dissolved the alumina ore in a bath of cryolyte (a mineral containing flourine, sodium and aluminum) and passed electric current through the solution. He patented the process, which was the first to become an inexpensive, commerical application. Production began in November, 1888 by the Pittsburgh Reduction Company started , which later became ALCOA, the Aluminum Company of America.

February 22: Jean-Charles-Athanase Peltier
(Born February 22, 1785: Died 1845)
French physicist who discovered the Peltier effect (1834), that at the junction of two dissimilar metals an electric current will produce heat or cold, depending on the direction of current flow. He retired from clockmaking early upon receiving an inheritance. He expanded his interests in phrenology, anatomy, microscopy, meteorology and electricity. The Peltier effect is used in devices for measuring temperature and, with the discovery of new conducting materials, in refrigeration units. Image: Peltier's atmospheric electricity gauge.

February 21: Heike Kamerlingh Onnes
(Born September 21, 1853: Died February 21, 1926)
Dutch winner of the Nobel Prize for Physics in 1913 for his work on low-temperature physics and his production of liquid helium. He discovered superconductivity, the almost total lack of electrical resistance in certain materials when cooled to a temperature near absolute zero.

February 20: Henri Moissan
(Born September 28, 1852: Died February 20, 1907)
French chemist who received the 1906 Nobel Prize for Chemistry for the isolation of the highly reactive gaseous element fluorine, and the development of the Moissan electric furnace. In 1884, he began studying fluorine compounds, and separated fluorine two years later when he electrolyzed a solution of potassium fluoride in hydrofluoric acid. Having isolated fluorine, he was then able to determine its physical and chemical properties. From 1892, with an electric arc furnace he designed, Moissan began experimenting with reactions possible at much higher temperatures than before and discovered many new compounds and was able to vaporize substances previously impossible. He developed the furnace for industrial production of acetylene.

February 19: Svante Arrhenius
(Born February 19, 1859: Died October 2, 1927)
Svante (August) Arrhenius was a Swedish physical chemist best known for his theory that electrolytes, certain substances that dissolve in water to yield a solution that conducts electricity, are separated, or dissociated, into electrically charged particles, or ions, even when there is no current flowing through the solution.

February 18: Edison Patent
In 1908, Thomas A. Edison was issued a U.S. patent for an improvement to "Alkaline Storage Battery" (No. 879,612). Its purpose was to reduce foaming of the electrolyte in such batteries while in operation, which Edison attributed to the presence of even microsopic quantities of organic matter. To correct the problem, the alkaline solution, such as caustic potash, is filtered through bone black that has been first purified by washing in a hot potash solution, then washing in water.

February 17: Horace Bénédict de Saussure
(Born February 17, 1740: Died January 22, 1799)
Swiss physicist, geologist, and early Alpine explorer. He made an extensive study of the structure of the Alps, described in the four volumes of Voyages dans les Alpes (1779-96). His theory was neptunian, but with uniformitarian overtones. The word geology was introduced into scientific nomenclature by Saussure with the publication of the first volume. Saussure developed what was probably the first electrometer (1766), used to measure electric potential. He also developed an improved hygrometer to measure atmospheric humidity (1783), the first to use human hair for the purpose.

February 16: Sir John Sealy Edward Townsend
(Born June 7, 1868: Died February 16, 1957)
British physicist who pioneered in the study of electrical conduction in gases. In 1898 he made the first direct measurement of the unit electrical charge (e). As a postgraduate, he was a research student of J. J. Thomson. In 1897, Townsend developed the falling-drop method for measuring e, using saturated clouds of charged water droplets (extended by Robert Millikan's highly accurate oil-drop method). He was first to explain how electric discharges pass through gases (Electricity in Gases, 1915) whereby motion of electrons in an electric field releases more electrons by collision. These in turn collide releasing even more electrons in a multiplication of charges known as an avalanche.

February 15: George Johnstone Stoney
Born 15 Feb 1826; died 5 Jul 1911.(Born February 15, 1826: Died July 5, 1911)
Irish physicist who introduced the term electron for the fundamental unit of electricity. At the Belfast meeting of the British Association in Aug 1874, in a paper: On the Physical Units of Nature, Stoney called attention to a minimum quantity of electricity. He wrote, "I shall express `Faraday's Law' in the following terms ... For each chemical bond which is ruptured within an electrolyte a certain quantity of electricity traverses the electrolyte which is the same in all cases." Stoney offered the name electron for this minimum electric charge. When J.J. Thomson identified cathode rays as streams of negative particles, each carrying probably Stoney's minimum quantity of charge, the name was applied to the particle rather than the quantity of charge.

February 14: Julius Arthur Nieuwland
(Born February 14, 1878: Died June 11, 1936)
Belgian-born American organic chemist who studied reactions of acetylene and invented neoprene. He was ordained as a priest (1903) before earning his Ph.D. (1904). He collaborated with DuPont chemists in the polymerization of acetylene and development of chloroprene, which in turn could be polymerized to the first really successful synthetic rubber, neoprene. This was superior to rubber in many ways such as in its resistance to sunlight, abrasion, and temperature extremes.

February 13: William B. Shockley
(Born February 13, 1910: Died August 12, 1989)
English-American engineer and teacher, cowinner (with John Bardeen and Walter H. Brattain) of the Nobel Prize for Physics in 1956 for their development of the transistor, a device that largely replaced the bulkier and less-efficient vacuum tube and ushered in the age of microminiature electronics.

February 12: Electrostatic generator patent
In 1935, a patent was issued to Robert Jemison Van de Graaff for his Electrostatic Generator design (U.S. No. 1,991,236) which would generate direct-current voltages higher than the 700,000-V which was the state of the art at the time using other methods. It consisted of two large, hollow approximately spherical domes on insulated columns. A silk belt ran on rollers between the base of the column to the interior of the dome. Charges from a 5000-V source are transferred to the belt near the lower roller, carried upward and are collected by a metal comb connected to the interior of the metal dome. By nature, charges cannot remain on the interior surface of a hollow body, and therefore move to, and accumulate on the exterior of the dome. Two such domes with opposite charges could generate a potential difference of 1,500,000-V between them.

February 11: Richard Hamming
(Born February 11, 1915: Died January 7, 1998)
American computer scientist who worked on computer error-detecting and correcting codes, now called Hamming codes (1947). These processes allow computers to correct their own errors, made innovations possible in modems, compact disks and satellite communications. He contributed to programming languages in general and work on numerical analysis and the Hamming spectral window (used to smooth data before Fourier analysis is carried out). Early in his career, Hamming taught at the University of Louisville. During WW II he worked on computers used in creating the Manhattan Project, the first atomic bomb. From 1946, for 30 years, he was with Bell Telephone Labs, eventually becoming head of computing science research.

February 10: Walter H. Brattain
(Born February 10, 1902: Died October 13, 1987)
Walter Houser Brattain was an American scientist born in China who, with John Bardeen and William B. Shockley, won the Nobel Prize for Physics in 1956 for investigating semiconductors (materials of which transistors are made) and for the development of the transistor. At college, he said, he majored in physics and math because they were the only subjects he was good at. He became a solid physicist with a good understanding of theory, but his strength was in physically constructing experiments. Working with the ideas of Shockley and Bardeen, Brattain's hands built the first transistor. Shortly, the transistor replaced the bulkier vacuum tube for many uses and was the forerunner of microminiature electronic parts.

February 9: Herbert Alexander Simon
(Born June 15, 1916: Died February 9, 2001)
American social scientist who was a pioneer of the development of computer artificial intelligence. In 1956, with his long-time colleague Allen Newell, Simon produced the computer program, The Logic Theorist, a computer program that could discover proofs of geometric theorems. It was the first computer program capable of thinking, and marked the beginning of what would become known as artificial intelligence. It proved many of the theorems of symbolic logic in Whitehead and Russell's Principia Mathematica. He is further known for his contributions in fields including psychology, mathematics, statistics, and operations research, all of which he synthesized in a key theory for which he won the 1978 Nobel Prize for economics.

February 8: Dennis Gabor
(Born June 5, 1900: Died February 8, 1979)
Hungarian-born British electrical engineer who won the Nobel Prize for Physics in 1971 for his invention of holography, a system of lensless, three-dimensional photography that has many applications. He first conceived the idea of holography in 1947 using conventional filtered-light sources. Because such sources had limitations of either too little light or too diffuse, holography was not commercially feasible until the invention of the laser (1960), which amplifies the intensity of light waves. He also did research on high-speed oscilloscopes, communication theory, physical optics, and television. Gabor held more than 100 patents.

February 7: Galileo Ferraris
(Born October 31, 1847: February 7, 1897)
Italian physicist who studied optics, acoustics and several fields of electrotechnics, but the most important discovery was the rotating magnetic field that he applied to the first induction motor (with 4 poles) in May-June 1885. The principles of the induction motor provided what is now the principal device for the conversion of electrical power to mechanical power. He did not want to take out a patent on his inventions and refused a large sum from an American company, because he felt that the discovery should be put at the service of everyone: ``I am a professor, not an industrialist'', he said with regard to the offer.

February 6: Cryotron
In 1957, the cryotron, a superconductive computer switch is announced. Developed by Dudley Allen Buck at the Massachusetts Institute of Technology, the cryotron was the first practical use of superconductivity - the ability of some metals to conduct current with no resistance at extremely low temperatures (below -420 degrees Fahrenheit). Its operation was based on the effects of magnetic fields on superconductivity at liquid helium temperatures. The cryotron was hailed as a revolutionary component for miniaturizing the room-sized computers of the 1950s. Image: in the hand of its inventor is the incredibly small cryotron (100 could fit in a thimble).

February 5: Franklin Institute
n 1824, Samuel Vaughan Merrick and William H. Keating founded "The Franklin Institute of the State of Pennsylvania for the Promotion of the Mechanic Arts" to honor Ben Franklin and advance the usefulness of his inventions. First located in the Philadelphia County Court House (known today as Independence Hall), it soon was moved in a new location where it remained for its first century. In 1930, funds were raised ($5.1 million in just 12 days) to move again into a new building which opened to the public on 1 Jan 1934. There it is complemented by the Fels Planetarium, the second planetarium in the U.S. Its construction began in 1933, the donation of Samuel S. Fels.

February 4: Hendrik Antoon Lorentz
(Born July 18, 1853: Died February 4, 1928)
Dutch physicist and joint winner (with Pieter Zeeman) of the Nobel Prize for Physics in 1902 for his theory of the influence of magnetism upon electromagnetic radiation phenomena. The theory was confirmed by findings of Zeeman and gave rise to Albert Einstein's special theory of relativity. From the start, Lorentz made it his task to extend James Clerk Maxwell's theory of electricity and of light. Already in his doctor's thesis, he treated the reflection and refraction phenomena of light from this new standpoint. His fundamental work in the fields of optics and electricity revolutionized conceptions of the nature of matter. In 1878, he published an essay relating the velocity of light in a medium, to its density and composition.

February 3: Oliver Heaviside
(Born May 18, 1850: Died February 3, 1925)
English physicist who predicted the existence of the ionosphere. In 1870, he became a telegrapher, but increasing deafness forced him to retire in 1874. He then devoted himself to investigations of electricity. In 1902, Heaviside and Kennelly predicted that there should be an ionised layer in the upper atmosphere that would reflect radio waves. They pointed out that it would be useful for long distance communication, allowing radio signals to travel to distant parts of the earth by bouncing off the underside of this layer. The existence of the layer, now known as the Heaviside layer or the ionosphere, was demonstrated in the 1920s, when radio pulses were transmitted vertically upward and the returning pulses from the reflecting layer were received.

February 2: Ethyl gasoline
In 1923, the first sale was made of anti-knock gasoline containing a tetra-ethyl lead compound. First sold in Dayton, Ohio, this new formulation of ethyl gasoline was the the result of seven years of testing at least 33,000 compounds as additives to influence the combustion rate of the fuel. Previously, on hard acceleration, an engine sometimes made knocking, popping or crackling sounds. Knocking sapped power and could damage the engine. The suitability of tetra-ethyl lead, made from alcohol and lead, was the discovery of Thomas Midgely, Jr., of the General Motors Research Laboratories, located in Dayton. Decades later, the toxicity of the lead present in automobile emissions was recognized, and leaded gasoline is no longer sold.

February 1: Clinton Joseph Davisson
(Born October 22, 1881: Died February 1, 1958)
American experimental physicist who shared the Nobel Prize for Physics in 1937 with George P. Thomson of England for discovering that electrons can be diffracted like light waves, thus verifying the thesis of Louis de Broglie that electrons behave both as waves and as particles. By reflecting a beam of electrons from a metallic crystal, they recognized diffraction patterns similar to those of X rays and other electromagnetic waves. This discovery has been applied tothe study of nuclear, atomic, and molecular structure. Davisson helped develop the electron microscope which uses the wave nature of electrons to view details smaller than the wavelength of visible light.

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