Sunday, June 26, 2011

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:


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

William Thompson, 1st Barron Kelvin Wikipedia Entry

Sunday, June 5, 2011

John Couch Adams





John Couch Adams was born on June 5, 1819, in Cornwall, England. His father was a tenant farmer and his mother had a small estate. His early companions were the library of books, some on astronomy, that his mother had inherited from her uncle. At a village school in Laneast he learned algebra before the age of 12. Through his teens he avidly read books on mathematics and astronomy and in 1839 he entered St. John's College, Cambridge, graduating in 1843. Soon after graduation he obtained a fellowship and stayed at St. John's as a tutor.

After graduation he directed his attention to the problem of the irregularities in the observed orbit of the planet Uranus. The planet Uranus, visible to the naked eye, had been known since ancient times, but due to its slow orbit it was presumed to be a star. It was not until 1781 that English astronomer William Herschel identified it as a planet. Subsequent observations of its orbit showed that it had an irregular orbit, deviating what had been predicted. Using Newton's law of gravitation, Adams showed that the irregularity in Uranus' orbit was due to the presence of another planet.

In Autumn of 1845 he communicated his finding to James Challis, the director of the Cambridge Observatory, and George Airy, the Astronomer Royal at Greenwich, but neither acted upon his results until after Urbain LeVerrier, a French mathematician, published similar results the next summer. Airy attempted to find the planet but because he was using outdated star charts he failed to recognize it when he saw it, and it was instead first recognized by Johan Galle and Heinrich d'Arrest, working in Berlin, using LeVerrier's results. Precedence of the discovery was given to LeVerrier because Adams' results were not published until after the fact.

In 1851 Adams got a fellowship at Pembroke College, which he kept until his death. Also in 1851 he published corrections of the table of the moon's paralax. In 1858 he took a position of professor of mathematics at St. Andrew's University, but stayed for only one year before taking the Lowedean professorship for astronomy and geometry at St. John's College, Cambridge. In 1860 he replaced Challis as director of the Cambridge observatory. He remained at the observatory till his death. Honors won by Adams include the Copley Medal, from the Royal Society, in 1848 and though offered a knighthood during Queen Victoria's 1847 visit to Cambridge, he refused.

He died on January 21, 1892 at the Cambridge Observatory.


References:

Sheehan, William and Thurber, Steven; "John Couch Adams's Asberger syndrome and the British non-discovery of Neptune"; Records and Notes of the Royal Society(2007)61:285-299

"Prof. John Couch Adams"; Journal of the British Astronomical Association(1893)2:196-197

Obituary in Monthly Notices of the Royal Astronomical Society(1893)53:184-209

John Couch Adams Wikipedia Entry

Wednesday, June 1, 2011

Sir David Bruce






David Bruce was born in Melbourne, Australia on May 29, 1855 to parents from Scotland. He was educated at Stirling High School and the University of Edinburgh, graduating in 1881. Two years later he entered the Army Medical Service and served in Malta and Egypt. While in Malta he isolated the organism responsible for Malta fever, later named Brucella Militensis, from goat's milk. His work was aided by his wife, Mary Elizabeth Bruce who assisted him in his laboratory work.

Bruce left Malta in 1889 and served as assistant professor of pathology at the British Army Medical School at Netley and in 1894 went to South Africa where he served in the South African War earning a special promotion to lieutenant colonel in 1900. In South Africa he studied many tropical diseases including cholera, dysentery, and sleeping sickness. During his investigation of sleeping sickness, called nagana in Africa, he sent the corpse of an infected dog to England, from which the causative organism Trypanasoma brucei was isolated.

Bruce was knighted in 1908 and published many articles published in tropical medicine journals. He served as the commandant of the Royal Army Medical School at Netley from 1904 to 1908.

He died on November 27,1931.


References:

"Sir David Bruce"; American Journal of Public Health (1932)22:179-180

"Sir David Bruce KCB, D.Sc., LL.D., M.B., F.R.C.P., F.R.S."; Canadian Medical Association Journal; (1932)26:216

Sir David Bruce Wikipedia Entry