Edward Condon

Edward Uhler Condon was born in Alomogordo, New Mexico on March 2, 1902. His father built railroads and the family moved about the western United States as his work required. Because of his family's movements young Condon attended many different schools. Condon developed an early interest in astronomy, sparked by the 1910 appearance of Haley's Comet and read everything he could on the subject. Later, in high school, he developed an interest in electronics and with the help of his high school physics teacher, William H. Williams, was able to make a number of electrical instruments. After graduating from high school he took a job working as a reporter for the Oakland Enquirer where he reported on labor unions. When his journalism was used to falsely convict labor activists he gave up journalism and went to the University of California at Berkeley to study physical science.

Initially Condon studied chemistry at Berkeley, but when his old high school teacher W. H. Williams took a job in the physics department at Berkeley, Condon switched to physics. Condon excelled in physics, earning his bachelors in three years and then going directly to graduate work, earning his PhD in 1926. For his thesis he outlined what has come to be known as the Franck-Condon Principle. When the elctrons of a molecule are excited the nucleus remains in the same position. The electron will jump up energy levels and then fall back, emitting electromagnetic radiation, but he nuclei of the molecule or atom remains relatively stationary.

At the time an doctorate in physics was not complete without a trip to Germany to study quantum mechanics, which at the time was quickly being discovered. Condon received a National Research Council fellowship and made the trip to Germany in the fall of 1926. While there he studied under Max Born and was soon overwhelmed by the unprecedented pace at which new developments in quantum mechanics were being published. In 1927 he took a job writing popular science for Bell Laboratories. In 1928 he took a position as a lecturer at Columbia University, where he taught graduate level classes on quantum mechanics and electromagnetic radiation. In 1927 Condon took a position as an associate professor of physics at Princeton University. During the years at Princeton Condon co-wrote with Philip M. Morse the first English language treatment of quantum mechanics, published in 1929, and with G.H. Shortly he wrote Theory of Atomic Spectra, a primary text on the subject, published in 1935.

In 1937 Condon became associate research director at the Westinghouse Electric Company, where he brought the company into the nuclear age. He briefly worked on the Manhattan project, but resigned because he disagreed with the reading and censorship of personal letters. Afterward Condon worked at Berkeley on the problem of separating uranium-235 from uranium-238. In 1945 Condon was appointed director of the National Bureau of Standards (now known as the NIST). During his time at the NIST Condon was dogged by questions about his loyalty to his country. In 1951 Condon was forced to testify before the United States House Un-American Activities Committee. The scientific community widely supported Condon and during his troubles with the HUAC Condon was elected president of the American Association for the Advancement of Science. Condon also served as the president of the American Physical Society. Condon worked as a professor of physics at Washington University in Saint Louis, Missouri from 1956 to 1963 and at the University of Colorado at Boulder from 1963 to 1970. Condon retired in 1970.

Condon died on March 26, 1974.


References:

Branscomb, Lewis; "Edward U. Condon: 1902-1974"; retrieved from library.wustl.ed

Edward U. Condon interviewed by Charles Weiner; retrieved from aip.org

Morse, Philip M.: "Edward Uhler Condon: 1902-1974"; from Biorgraphical Memoirs; National Academy Press;

Edward Condon Wikipedia Entry

Henry Kendall

Henry Way Kendall was born on December 9, 1926 in Boston, Massachusetts. His father was an industrialist and he had two siblings, a younger brother and sister. He grew up in Sharon, Massachusetts and attended Deerfield Academy in Deerfield, Massachusetts, graduating in 1945. As a child he had an intense curiosity for things mechanical, chemical and electrical. He attended the United States Merchant Marine Academy, and served on a troop transport ship in the north Atlantic during the winter of 1945-46. With the end of the World War II he enrolled in Amherst College, graduating with a bachelors in mathematics in 1950. After graduation he went to the Massachusetts Institute of technology where he earned his Ph.D. in physics. He did post-doctoral work at M.I.T. and Stanford university then returned to M.I.T. as a faculty member.

Kendall's research involved using particle accelerators to probe the make up of the atom. In the 1960s and 70s Kendall worked with Jerome Friedman and Richard Taylor scattering electrons off of protons, neutrons, duterons and other heavier nuclei. These experiments confirmed the existence of quarks, small, sub-nuclear particles that protons and neutrons are made of. Quarks take their name from a line in Finnegan's Wake by James Joyce, and come in two kinds, up quarks and down quarks. Protons are made up of two up quarks and one down quark and neutrons are made up of two down quarks and one up quark. For their work confirming the existence of quarks Kendall, Friedman, and Taylor were awarded the 1990 Nobel Prize in physics.

In a addition to his work in physics, Kendall was also an avid outdoorsman, mountain climber and scuba diver. In the 1960s Kendall served as an adviser to the United States Department of Defense. In 1969 he co-founded the Union of Concerned Scientists and served for many years as its chairman. The Union of Concerned Scientists is a non-profit group that advocates sensible environmental and sustainable agricultural policies. He was elected to the National Academy of Sciences in 1977 and was inducted into the American Alpine Club's Hall of Mountaineering Excellence in 2012.

He died on February 15, 1999 as the result of a scuba diving accident while exploring an underwater cave in Wakulla Springs State Park in Florida.


References:

Bjorken, James D., Friedman, Jerome I., Taylor, Gottfried, Kurt and Taylor, Richard B.; "Henry Way Kendal: 1926-1999"; National Academy Press; 2009

Kendall, Henry W., Nobel Autobiography

Kendall, Henry W. and Aasserud, Finn; "Oral History Transcript - Dr. Henry Kendall"; accessed at aip.org.

 Henry Way Kendall Wikipedia Entry

Jean Perrin

Jean Baptiste Perrin was born on September 30, 1870 in Lille, France. He attended Ecole Normale Superieure in Lille and worked there as a physics assistant from 1894 to 1897. He earned his doctorate in 1897 for a thesis on cathode and x-rays. After graduation he was appointed to a readership in physical chemistry at the Sorbonne, University of Paris. He became a professor there in 1910. He served as an officer in the French Army's Engineering Corp. during the World War I and he was removed from his professorship when the Germans occupied Paris in 1940.

Perrin's early work on cathode rays proved that they were made of  negatively charged particles. His work covered a number of topics in physics including the effects of x-rays on the conductivity of gasses, fluorescence, and the radioactive disintegration of radium. He suggested that stars obtained their energy from the thermonuclear reactions of hydrogen. He wrote numerous books and papers including Les Atomes where he describes his studies on Brownian motion, which confirmed the atomic theory, that all matter is made of atoms.

In 1905 Albert Einstein had published a paper on Brownian motion describing how it was the result of atomic theory. Brownian motion is the random motion of particles suspended in a liquid, discovered in 1827 by Robert Brown, an English botanist who watched pollen particles suspended in water. Suspended in a liquid, the particles are constantly bombarded by moving molecules of the liquid. This causes the visible particles to move in random directions. Einstein's paper was theory and it was Perrin who experimentally demonstrated that matter is made of molecules. Perrin was able to use Brownian motion to determine a value for Avagadro's constant that closely agreed with the value obtained using Dalton's law of molecular motion. Avagadro's constant is the number of molecules in a mole of a substance. For his work, proving the atomic theory Perrin was awarded the 1926 Nobel Prize for Physics.

Perrin was the recipient of numerous other awards, including the Joule Prize from the Royal Society in 1896 and the La Caze Prize from the Paris Academy of Sciences in 1914. He was made a commander in the French Legion of Honor in 1926 and a commander in the Legion of Leopold (Belgium). He was awarded numerous honorary doctorates.

In 1940 he fled German occupied France to the United States where he died on April 17, 1942. After World War II, in 1948, his remains were returned to France aboard the light cruiser Jeanne d'Arc and he was buried in the Pantheon in Paris, France.


References:

Allison, Andy; "Jean Perrin and Atomic Theory: Calculating Avagadro's Constant"; Physics @ Suite 101; October 3, 2008

Jean Perrin Nobel Biography

Jean Perrin Wikipedia Entry

Theodore Maiman

Theodore Harold Maiman was born or July 11, 1927 in Los Angeles, California. The next year he moved to Denver, Colorado with his parents. His father, Abraham Maiman, was an electrical engineer and an inventor. Maiman was curious to how things work and was always taking things apart, to the dismay of his parents. In high school he worked in a electronics repair shop to earn money.

He earned a BS in engineering physics from the University of Colorado in 1949 and then went on to Stanford University where he earned a MS in electrical engineering in 1951 and a Ph.D. in physics in 1955 completing a thesis, under Willis Lamb, involving detailed optical measurements of the fine structure splittings in excited helium atoms

He then joined Hughes Laboratories where he worked on the stimulated emission of microwave energy. A MASER (microwave amplification by stimulated emission of radiation) had been invented earlier by Charles Townes working at Bell Laboratories. Townes and Arthur Schawlow in their paper suggest that their success, creating the MASER, could be repeated making a device that emits a coherent beam of light in the visual spectrum. This is called a LASER (light amplification by stimulated emission of radiation).

Maiman was the first to produce a working LASER, announcing his invention at a press conference on July 7, 1960. He published his results in the British journal Nature, after his paper was refused by Physical Review Letters because it was deemed to be to repetitive. Maiman left Hughes Laboratories in 1962 and went on to work for a series of different companies, some of his own founding, working on LASERs and their applications.

Maiman was twice nominated for the Nobel Prize and was a member of the National Academy of Science and National Academy of Engineering. He won the Oliver E Buckley Prize in 1966 and won the 1983/4 Wolf Prize for Physics. He was inducted into the Inventors Hall of Fame in also in 1984.

He died on May 5, 2007.

References:

Day, Lance; McNeil Ian; "Maiman, Theodore Harold" in Biographical Dictionary of the History of Technology; Taylor & Francis; 1998

Martin Douglas; "Theodore Maiman Dies, 79; Demonstrated First Laser";New York Times; May 11, 2007

Wycoff, Edwin Britt; Laser Man: Theodore Maiman and His Brilliant Invention; Enslow Publishers Inc; 2007

Theodore Maiman Wikipedia Entry

William Thompson, Baron Kelvin

William Thompson was born on June 26, 1824 in Belfast, Ireland, of Scottish-Irish descent. His father, James Thompson was at the time a mathematics professor at the Royal Belfast Academical Institution. His mother, Margaret Gardner, died in 1830 and in 1832 his father took his six children with him to Glasgow, Scotland, where he had been elected chair of mathematics at the University of Glasgow, his alma mater.

William, and his older brother James received their early education at home, from their father. He entered the University of Glasgow in 1834 at the age of ten. At 12 he won a prize for translating Lucian of Samosata's Dialogs of the Gods from Latin into English. His first scientific paper was published in 1841 and in that year he entered St. Peter's College, Cambridge to read for the mathematical tripos. During his time at Cambridge he rowed for his college and remained involved in nautical pursuits throughout his life. He graduated in 1845, second wrangler (the university examiner commented that the Senior Wrangler "was not fit to cut pencils for Thompson") and winning first place in the Smith's Prize competition. He was elected fellow, shortly thereafter.

At the time experimental physics was not taking place at Cambridge, so after graduation he took his fellowship to Paris, and he worked in the laboratory of Henri Regnault for a year, where he determined data on a number of physical constants. In 1846 the chair of natural philosophy at Glasgow University became vacant and Thompson was elected. He remained in the position for fifty-three years until his retirement in 1899, despite many invitations to leave and go elsewhere. He was an inexhaustible worker, producing almost six hundred papers, seventy patents, as well as a number of books during his tenure.

Thompson is most famous for his work on an absolute zero temperature, a temperature at which entropy is reduced to its lowest possible value. The Kelvin temperature scale, named after Thompson, has its zero at -273.15 degrees Celsius or -459.67 degrees Fahrenheit. At this temperature nearly all molecular motion stops and pure substance form perfect crystals. It is not possible to reach absolute zero artificially, but there are techniques to get within a billionth of a degree using cooling lasers.

Thompson served as the electrical engineer during the laying of the first successful Transatlantic Telegraph Cable and was knighted for his services. He was elected to the Royal Society in 1851 and won the Copley Medal in 1883. His title, Barron Kelvin, bestowed on him in 1892, origninated from the River Kelvin which runs through the grounds of the University of Glasgow and he is the first scientist who served in the House of Lords.

He died on December 17, 1907.

References:

Fitzgerald, George Francis;Lord Kelvin: Professor of Natural Philosophy in the University of Glasgow 1846-1899 with an Essay on His Scientific Work;J. MacLehose; 1899

McKie, Dr. Douglas;"William Thompson: Lord Kelvin (1824-1907)";New Scientist(1957)3:11-13

William Thompson, 1st Barron Kelvin Wikipedia Entry

John van Vleck

John Hasbrouck van Vleck was born on March 13, 1899 in Middletown, Connecticut. Both his father and grandfather were university professors. Van Vleck, an only child, moved with his parents to Wisconsin when he was seven when his father became a professor at the University of Wisconsin. He was educated in the Madison, Wisconsin public schools and went on to the University of Wisconsin, where he played in the band. His undergraduate education included courses on railroads and French literature, in addition to physics. Although not an athlete, he was a fan of American football, remembering the scores of games years after they had been played. He graduated in 1920 with a degree in physics. He entered the graduate program at Harvard University and graduated with a Ph.D. in 1922 completing a thesis on the binding energy of a helium atom.

After his doctorate he stayed at Harvard for a year teaching, before taking a job at the University of Minnesota, where he taught graduate physics courses from 1923-1928 He returned to teach at his alma mater, the University of Wisconsin from 1928-1934 and he taught at Harvard from 1934-1969. During World War II he worked on radar at the MIT Radiation Laboratory and participated in the Manhattan Project as part of a committee, with J. Robert Oppenheimer, that studied the feasibility of and designed the first atomic bombs. He also served on the Los Alamos Review Committee, which designed the firing mechanism for "Little Boy", the first atomic bomb used on Hiroshima, Japan.

Van Vleck's early research delt with diamagnetic and paramagnetic materials, and how their behavior could be understood when the new (at the time) field of quantum mechanics was applied. Paramagnetic materials, when exposed to an external magnetic field, are attracted to it, diamagnetic materials are slightly repelled. Neither of the materials retain a magnetic field when the external field is removed. The reason for these behaviors is the electron structures of the different materials, paramagnetic materials have unpaired electrons and diamagnetic do not. Van Vleck also worked on crystal field theory, a branch of chemistry that has to do with the complexes formed by transition metals. He showed that ligands (the atoms or groups of atoms that bond to transition metals) form covalent bonds, not just ionic bonds, with the central metal atom.

In 1977 van Vleck, along with Philip Anderson and Sir Nevil Mott, was awarded the Nobel Prize for Physics "for their fundamental theoretical investigations of the electronic structure of magnetic and disordered systems". Other awards won by van Vleck include the National Medal of Science in 1966 and the Lorentz Medal from the Royal Netherlands Academy of Arts and Sciences in 1974.

Van Vleck retired in 1969 and died in his Cambridge, Massachusetts home on October, 27 1980.


References:

Anderson, P.W.; "John Hasbrouk Van Vleck"; in Biographical Memoirs Vol. 56; National Academy Press; 1987

Carey, Charles W.; American Scientists; Infobase Publishing; 2006

John H. Van Vleck Nobel Autobiography

John Hasbrouck Van Veck Wikipedia Entry

Albert Abraham Michelson

Albert Abraham Michelson was born on December 19, 1852 in Strenlo, Prussia (now Poland). His family moved two years later to Virginia City, Nevada where his father was a merchant. The family later moved to San Francisco, California, where Michelson first attended public school. He graduated in 1869 and President Ulysses S. Grant appointed him to the United States Naval Academy from which he graduated in 1873 and served for two years as an ensign on a cruise of the West Indies. After the cruise he he returned to the Naval Academy teaching chemistry and physics. In 1879 he was posted to the Naval Almanac Office. A year later he obtained a leave of absence so that he could go to Europe to continue his education where he visited the universities of Berlin and Heidelberg, and the College de France and the Ecole Polytechnique in Paris.

Michelson was fascinated with the speed of light. While at Annapolis he had repeated the Jean Bernard Leon Foucault's 1850 measurement, improving Foucault's rotating mirror system. After two years of studying in Europe he resigned from the Navy in 1881. In 1883 he took a position as a professor of physics at the Case School of Applied Science in Cleveland, OH. There he concentrated on developing an interferometer to use in his experiments.

In 1887 he performed, with Edward Morley, the experiment for which he is most famous. At the time it was believed that the earth (and everybody on it) was traveling through the aether, and electromagnetic waves (light) were affected by the movement of the aether. In order to test this effect Michelson and Morely used a light beam that was split in half and half was reflected in a right angle to the original beam. The light beams were then reflected back to the starting point where the interferometer was used to determine their velocities. The result was a null result and both light beams, traveling identical distances had both arrived back at the starting point at the same time, thus had equal velocities. This result proved that there was no aether and light could propagate at the same speed in any direction. For this work Michelson was awarded the Nobel Prize in 1907, becoming the first American to win the prize.

In 1889 Michelson moved to Clark University in Worcester, MA and in 1892 he was appointed professor of physics at the new University of Chicago. He continued his attempts to measure the speed of light and developed a way to use interferometry to determine the diameter of stars. In addition to the Nobel he has also won the Copley medal, the Henry Draper Medal and a gold medal from the Royal Astronomical Society. For his work he was awarded several honorary degrees and a crater on the moon is named after him

He died on May 9, 1931.


References:

Law, Fredrick Houk; Modern Great Americans: Short Biographies of 20 Great Americans of Modern Times Who Won Wide Recognition for Achievements in Various Types of Activity; Ayer Publishing, 1969

Albert A. Michelson, Nobel Biography

Albert Abraham Michelson Wikipedia Entry

Christian Andreas Doppler

Christian Andreas Doppler was born on November, 29, 1803 in Salzburg, Austria. He was the son of a successful stonemason, but as he grew he was unable to work in his father's business due to his frailty and generally poor health. Doppler attended primary school in Salzburg and Secondary school in Linz. Unsure about the academic potential of their son, his parents consulted a mathematics professor who suggested that he study higher mathematics at the Vienna Polytechnic Institute. Doppler began his studies there in 1822. He excelled at mathematics and graduated in 1825. After graduation he returned to Salzburg, where he attended philosophy lectures at the Salzburg Lyceum and afterward studied higher mathematics, mechanics and astronomy at the University of Vienna.

At the end of his studies he was appointed assistant to mathematics professor A. Burg at Vienna University. He remained in this position for four years publishing papers on mathematics. At the age of 30 he began competing to find a permanent position. At that time open competitions were held to fill open professorships. Doppler competed for many positions and while he was waiting he supported himself by working as a bookkeeper for a cotton spinning factory. Despairing of not getting a position, Doppler sold his things in order to finance a trip to America, but before his final decision was made he was offered a position at the Technical Secondary School in Prague. Doppler was ambitious and wanted to do more than teach elementary mathematics. He applied to become a professor at the Polytechnic in Prague without success, until 1841 when he was appointed to the post.

Doppler's tenure at the Polytechnic was rocky and his students complained that his examinations were to difficult. He was reprimanded and forced to reexamine his students. In 1844 he was forced to give up teaching due to his poor health. He returned in 1846. Leaving his troubles in Prague behind he took a position as professor of mathematics, physics and mechanics at the Academy of Forests and Mines in Banska Stiavnica. As a result of the stormy revolutionary year 1848 Doppler sought refuge and went to Vienna, where he was appointed as the first director of the Institute of Physics at Vienna University.

Not all of Doppler's contemporaries considered him a brilliant mathematician, but he had an original way of looking at things that not all appreciated. For years Doppler attempted to become a member of the Bohemian Society, and despite good recommendations it was not until 1843 that he was elected in. In 1842 he presented a paper on the color of binary stars and how it is affected by their motion, to or away from the observer. Although the color changes of binary stars are not great enough to be significant, light is a wave and if a star emitting light is traveling toward the observer it will shorten the wavelength of light it is emitting moving it toward the red end of the visual spectrum. If the star is moving away from the observer the wavelengths grow longer, shifting the wavelength to the blue/violet end of the visible spectrum. These effects are called red shift and blue shift. This effect is most easily demonstrated with sound waves. A siren approaching the observer has a higher pitch than it would have if it were stationary with respect to the observer. As the siren passes the observer the pitch drops lower than it would have if it were stationary with respect to the observer. In 1845 Doppler performed an experiment with trumpeters on a railway car playing a single sustained note. As the railway approached and passed musicians recorded what notes they heard, demonstrating that the horn's pitch lowered as they passed the observer. This effect is called the Doppler effect.

Doppler died on March 17, 1853 in Venice, then a part of the Austrian Empire.

References:

O'Connor, JJ and Robertson, EF; "Christian Andreas Doppler"; MacTutor History of Mathematics Archive; University of St. Andrews

Maizlin, Z.V.; The Wonders of Radiology; Create Space; 2010

Christian Doppler Wikipedia Entry