## Thursday, 9 August 2012

### On This Day in Math - August 9

You don't understand anything until you learn it more than one way.
— Marvin Minsky

The 222nd day of the year; 222 is called a sphenic (Greek for wedge) number. They have three distinct prime factors. 30= 2x3x5 is the smallest sphenic number. Can you find two consecutive numbers that are both sphenic numbers?

EVENTS
0975 "The Sun was eclipsed . . . . Some people say that it was entirely total. During the hours mao and ch'en (some time between 5 and 9 h) it was all gone. It was the colour of ink and without light. All the birds flew about in confusion and the various stars were all visible. There was a general amnesty (on account of the eclipse)." From: Nihon Kiryaku. "At the hour ch'en (7-9 h), the Sun was eclipsed; it was completely total. All under heaven became entirely dark and the stars were all vis ible."
From: Fuso Ryakki. "The Sun was eclipsed; it was all gone. It was like ink and without light. The stars were all visible (or: stars were visible in the daytime)." From: Hyaku Rensho. These three Japanese quotations refer to a total solar eclipse of 9 August AD 975. Quoted in Historical Eclipses and Earth's Rotation, by F Richard Stephenson, Cambridge University Press, 1997, pages 267 and 268. *NSEC
1207 An educational institution is founded for the study of the works of Bhaskara II, an Indian mathematician and astronomer.*VFR
Bhaskara II was rightly achieved an outstanding reputation for his remarkable contribution. In 1207 an educational institution was set up to study Bhaskaracharya's ("Bhaskara the teacher")works. A medieval inscription in an Indian temple reads: Triumphant is the illustrious Bhaskaracharya whose feats are revered by both the wise and the learned. A poet endowed with fame and religious merit, he is like the crest on a peacock. It is from this quotation that the title of Joseph's book comes. *SAU

1654 Fermat to Carcavi "Monsieur, I was overjoyed to have had the same thoughts as those of M. Pascal, for I greatly admire his genius and I believe him to be capable of solving any problem he attempts. The friendship he offers is so dear to me and so precious that I shall not scruple to take advantage of it in publishing an edition of my Treatises. If it does not shock you, you could both help in bringing out this edition, and I suggest that you should be the editors: you could clarify or augment what seems too brief and thus relieve me of a care which my work prevents me from taking. I would like this volume to appear without my name even, leaving to you the choice of designation which would indicate the author, whom you could qualify simply as a friend." *York Univ Hist of Stats.

1658 Simon Douw obtains a patent for a pendulum clock that will draw Huygen’s attack in Horologium. “Today, no clock by Simon Douw is known; I find that most curious, it is as if he has been excised from history, deliberately. Dutch Court papers described Douw as "City clockmaker of Rotterdam... a master in the art of great tower, domestic or office clocks", ("en meester in de kunst van groote Toorn, Camer ofte Comptoirwerken"). Yet his mechanical insights. his escapement, also his drive mechanisms, are best, and now only, revealed by his Patent Grant on August 9th, 1658, and by the evidence and judgement in a claim and counterclaim started in the Provinces of Holland and West Friesland, but then referred to the Court of The Netherlands in October 1658, with a Judgement by Consent on December 5th, 1658. And that case went entirely in Douw's favour, against the highly favoured joint Complainants Huygens and Coster.
In itself, that is remarkable. Huygens, the Noble patrician, the most famous Dutch scientist, and the self-professed inventor of the pendulum clock, who had in the course of this trial published "Horologium", was forced by the judges to settle the case rather than face unfavourable verdict; also to concede Consent; also one-third Royalties to Douw. It would have been a crushing humiliation for Huygens, the seed of his libels. Subsequently, the Lower Court of Holland, Zeeland and Friesland confirmed to Douw, on December 16th and 19th 1658, their Upper Court's judgement by consent”. * From Keith Piggott

1975 To display Mexican-Lebanese friendship, Mexico issued a stamp of the Teacher’s Monument in Mexico City by I. Naﬀa al Rozzi, which shows Cadmus, a mythical Phoenician, teaching the alphabet.

BIRTHS

1537 Franciscus Barocius (9 August 1537 – 23 November 1604) born. In 1560 he published the ﬁrst important translation of Proclus’ commentary on the ﬁrst book of Euclid’s Elements. In 1587 he was brought before the Inquisition on charges of sorcery, more particularly of having caused a torrential rainstorm in Crete. *VFR

1602 Gilles de Roberval (August 9, 1602 – October 27, 1675)(His date of birth is given as 8th, 9th and 10th in various sources) was a French scientist who developed powerful methods in the early study of integration.*SAU Roberval was one of those mathematicians who, just before the invention of the infinitesimal calculus, occupied their attention with problems which are only soluble, or can be most easily solved, by some method involving limits or infinitesimals, which would today be solved by calculus. He worked on the quadrature of surfaces and the cubature of solids, which he accomplished, in some of the simpler cases, by an original method which he called the "Method of Indivisibles"; but he lost much of the credit of the discovery as he kept his method for his own use, while Bonaventura Cavalieri published a similar method which he independently invented.
Another of Roberval’s discoveries was a very general method of drawing tangents, by considering a curve as described by a moving point whose motion is the resultant of several simpler motions. He also discovered a method of deriving one curve from another, by means of which finite areas can be obtained equal to the areas between certain curves and their asymptotes. To these curves, which were also applied to effect some quadratures, Evangelista Torricelli gave the name "Robervallian lines."
(He also wrote a) work on the system of the universe, in which he supports the Copernican heliocentric system and attributes a mutual attraction to all particles of matter. *Wik

1757 Thomas Telford (9 August 1757 Glendinning, Westerkirk, Eskdale, Dumfriesshire, Scotland - 2 September 1834 (aged 77) 24 Abingdon Street, Westminster, London) He is the founder of modern bridge construction, his crowning achievement being the Menai suspension bridge in Wales. Do you know the shape of the cables on a suspension bridge? *VFR

1776 Count Amedeo Avogadro (9 August 1776, Turin, Piedmont – 9 July 1856) Italian chemist and physicist who found that at the same temperature and pressure equal volumes of all perfect gases contain the same number of particles, known as Avogadro's Law (1811) leading to the Avogadro's constant being 6.022 x 1023 units per mole of a substance. He realized the particules could be either atoms, or more often, combinations of atoms, for which he coined the word "molecule." This explained Gay-Lussac's law of combining volumes (1809). Further, Avogadro determined from the electrolysis of water that it contained molecules formed from two hydrogen atoms for each atom of oxygen, by which the individual oxygen atom was 16 times heavier than one hydrogen atom (not 8 times as suggested earlier by Dalton.) The Italian, Romano Amadeo Carlo Avogadro, had suggested [in 1811] that all gases have the same number of molecules in a given volume. Loschmidt figured out [in 1865] how many molecules that would be. John D. Cook suggested that maybe it should be called Loschmidt's constant, and pointed out three interesting coincidences involving Avogadro's Constant:
NA is approximately 24! (i.e., 24 factorial.)
The mass of the earth is approximately 10 NA kilograms.
The number of stars in the observable universe is 0.5 NA.
*John D. Cook, The Endeavour Blog

1819 Jonathan Homer Lane (August 9, 1819, Geneseo, New York – May 3, 1880, Washington D.C.) U.S. astrophysicist who was the first to investigate mathematically the Sun as a gaseous body. His work demonstrated the interrelationships of pressure, temperature, and density inside the Sun and was fundamental to the emergence of modern theories of stellar evolution.*TIS

1911 William Alfred "Willie" Fowler (August 9, 1911 – March 14, 1995)
American astrophysicist. He should not be confused with the British astronomer Alfred Fowler.
Fowler won the Henry Norris Russell Lectureship of the American Astronomical Society in 1963, the Eddington Medal in 1978, the Bruce Medal in 1979, and the Nobel Prize for Physics in 1983 for his theoretical and experimental studies of the nuclear reactions of importance in the formation of the chemical elements in the universe (shared with Subrahmanyan Chandrasekhar). *TIA

1927 Marvin Minsky (August 9, 1927 - ) Biochemist and the founder of the MIT Artificial Intelligence Project. Marvin Minsky has made many contributions to AI, cognitive psychology, mathematics, computational linguistics, robotics, and optics. He holds several patents, including those for the first neural-network simulator (SNARC, 1951), the first head-mounted graphical display, the first confocal scanning microscope, and the LOGO "turtle" device. His other inventions include mechanical hands and the "Muse" synthesizer for musical variations (with E. Fredkin). In recent years he has worked chiefly on imparting to machines the human capacity for commonsense reasoning. *TIS

1940 Linda Goldway Keen (8 August 1940- ) In addition to studying Riemann surfaces, Keen has worked in hyperbolic geometry, Kleinian groups and Fuchsian groups, complex analysis, and hyperbolic dynamics. In the field of hyperbolic geometry, she is known for the Collar lemma.
Keen has worked at the Institute for Advanced Study, Hunter College, University of California at Berkeley, Columbia University, Boston University, Princeton University, and the Massachusetts Institute of Technology, as well as at various mathematical institutes in Europe and South America. After her initial appointment in 1965, in 1974 Keen was promoted to Full Professor at Lehman College and the CUNY Graduate Center.
Keen served as president of the Association for Women in Mathematics during 1985-1986 and as vice-president of the American Mathematical Society during 1992-1995. She served on the Board of Trustees of the American Mathematical Society from 1999-2009 and as Associate Treasurer from 2009-2011. In 1975, she presented an AMS invited address and in 1989 she presented an MAA joint invited address. In 1993 she was selected as a Noether Lecturer. *Wik
1943 Jacques Lewiner, (9 August, 1943 - ) is a French physicist and inventor. He is Professor and Honorary Scientific Director of École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI ParisTech).
His works have been devoted to electrical insulators and particularly electrets, instrumentation and sensors, for instance in medical imaging, or on the improvement of telecommunication networks.
He has filed a large number of patent applications leading to industrial development, either through licenses granted to industrial companies or through start-up companies often created with former students or researchers. He has participated in the creation of various technology oriented start up companies, for instance Inventel, specializing in Telecommunications, Finsécur which develops and markets fire detection systems, Sculpteo which is an online 3D printing platform, Roowin in the field of chemical synthesis and Cynove in embedded electronics devices. Most of these companies have experienced a strong growth. For instance Inventel, which was the French leader for multimedia gateways was bought by Thomson SA in 2005.
Lewiner is laureate of the French Academy of Sciences in 1990, Knight in the National Order of the Legion of Honor, member of the French Academy of Technologies since 2005 and Honorary Fellow of the Technion. *Wik

DEATHS

1932 John Charles Fields died (May 14, 1863 - August 9, 1932). In his will he left funds for an international medal for contributions to mathematics. The International Congress of Mathematicians in Zurich in 1932 adopted the proposal, and the ﬁrst Fields Medals were awarded at the Oslo Congress in 1936 to Lars Ahlfors, age 29 of Harvard, and Jesse Douglas, age 39 of Massachusetts Institute of Technology. *VFR It became the most prestigious award for mathematicians, often referred to as the equivalent of a Nobel Prize for mathematicians. As a professor at the University of Toronto, he had worked to bring the International Congress of Mathematicians to Toronto (1924). The Congress was so successful that afterward there was a surplus of about $2,500 which Fields, as chairman of the organizing committee, proposed be used to fund two medals to be awarded at each of future Congresses. This was approved on 24 Feb 1931. He died the following year, leaving$47,000 as additional funding for the medals, which have been awarded since 1936.*TIS

1969 Cecil Frank Powell (5 December 1903 – 9 August 1969) British physicist and winner of the Nobel Prize for Physics in 1950 for his development of the photographic method of studying nuclear processes and for the resulting discovery of the pion (pi-meson), a heavy subatomic particle. The pion proved to be the hypothetical particle proposed in 1935 by Yukawa Hideki of Japan in his theory.*TIS

1994 Helena Rasiowa (June 20, 1917 – August 9, 1994) worked in algebraic logic and the mathematical foundations of computer science.*SAU

2006 James Alfred Van Allen (September 7, 1914 – August 9, 2006) American physicist who discovered the Earth's magnetosphere, two toroidal zones of radiation due to trapped charged particles encircling the Earth (also known as the Van Allen radiation belts). During WWII he gained experience miniaturizing electronics, such as in the proximity fuse of a missile. After the war, he studied cosmic radiation, taking advantage of the unused German stock of V2 rockets launched into the outer regions of the atmosphere, carrying research devices using radio to relay back the data gathered. He was also involved in the early U.S. space program, and he had radiation measuring instruments on the first U.S. satellite, Explorer 1, launched 31 Jan 1958 with follow-up carried out by satellites Explorer 3 and 4 later the same year.*TIS

2007 Graham Robert Allan (August 13, 1936 Southgate, London - August 9, 2007 (aged 70)) was an English mathematician, specializing in Banach algebras. He was a reader in functional analysis and vice-master of Churchill College at Cambridge University. *Wik

Credits
*CHM=Computer History Museum
*FFF=Kane, Famous First Facts
*NSEC= NASA Solar Eclipse Calendar
*SAU=St Andrews Univ. Math History
*TIA = Today in Astronomy
*TIS= Today in Science History
*VFR = V Frederick Rickey, USMA
*Wik = Wikipedia
*WM = Women of Mathematics, Grinstein & Campbell