## Wednesday, 17 August 2011

### On This Day in Math - Aug 17

Base eight is just like base ten, really… if you're missing two fingers!
~Tom Lehrer, "New Math"

The 229th day of the year; 229 is a prime, and is the smallest prime that added up to the reversal of its digits yields another prime, (229 + 992) = 1151 (can you find the next one?)

EVENTS
1655  William Oughtred writes to John Wallis to praise his methods in "Arithmetica Infinitorum" . It was received too late to be included in the first edition, but was included in the 1695 second edition.  *The Arithmetics of Infinitesimals, J. Stedall, pg 11

1811 “Having to conduct my grandson through his course of mathematics, I have resumed the study with great avidity. It was ever my favorite one. We have no theories there, no uncertainties remain on the mind; all is demonstration and satisfaction.” So wrote Thomas Jeﬀerson (1743– 1826) to Benjamin Rush. Taken from The Writings of Thomas Jeﬀerson, edited by A. A. Lipscomb, vol. 13 (1903), p. 75, as quoted from Cajori, Mathematics in Liberal Education, p. 109, which is a collection of interesting quotations on the value of mathematics.  The following year, his 70th, Jefferson describes his early affection for mathematics
in a letter to  William Duane "When I was young, mathematics was the passion of my life." *John Fauval, lecture at Univ of Va.

1825 A royal decree granted Neils Henrik Abel, then 23, sufficient funds for a year’s travel in France and Germany. *VFR

1877 Asaph Hall discovered Phobos, inner satellite of Mars. The two moons of Mars, Phobos and Deimos, were found when American astronomer Hall identified them after a long search, although their existence had been a source of speculation before. The possibility of Martian moons had been speculated long before Hall's discovery. The astronomer Johannes Kepler (1571–1630) even predicted their number correctly, although with faulty logic: he wrote that since Jupiter had four known moons and Earth had one, it was only natural that Mars should have two.
Perhaps inspired by Kepler (and quoting Kepler's third law), Jonathan Swift's satire Gulliver's Travels (1726) refers to two moons in Part 3, Chapter 3 (the "Voyage to Laputa"), in which the astronomers of Laputa are described as having discovered two satellites of Mars orbiting at distances of 3 and 5 Martian diameters, and periods of 10 and 21.5 hours, respectively. The actual orbital distances and periods of Phobos and Deimos of 1.4 and 3.5 Martian diameters, and 7.6 and 30.3 hours, respectively.
Hall discovered Deimos on August 12, 1877 at about 07:48 UTC and Phobos on August 18, 1877, at the US Naval Observatory in Washington, D.C., at about 09:14 GMT (contemporary sources, using the pre-1925 astronomical convention that began the day at noon, give the time of discovery as August 11, 14:40 and August 17 16:06 Washington mean time respectively)*Wik
In the words of Asaph Hall, "Of the various names that have been proposed for these satellites, I have chosen those suggested by Mr Madan of Eton, England, viz: Deimos for the outer satellite; Phobos for the inner satellite. These are generally the names of the horses that draw the chariot of Mars. "

1941 When Herbert Robbins saw the proof sheet of the title page of What is Mathematics? with only the name Richard Courant on it, his ﬁrst reaction was “My god, the man’s a crook.” Realizing that a quiet meeting on their co-authorship of the book would be impossible, Robbins wrote Courant on this date that, while the custom might be different in Europe, in this country the junior author did receive credit. Courant backed down, and so today we know this lovely book as one by Courant and Robbins. For the two sides of this story see Constance Reid, Courant in Gottingen and New York. The Story of an Improbable Mathematician (Springer 1976), 223– 226 and 230–232 as well as “An interview with Herbert Robbins,” The College Mathematics Journal, 15(1984), 4–6. *VFR

BIRTHS
1601 Pierre de Fermat (17 Aug 1601; 12 Jan 1665)French mathematician, often called the founder of the modern theory of numbers. Together with Rene Descartes, Fermat was one of the two leading mathematicians of the first half of the 17th century. He anticipated differential calculus with his method of finding the greatest and least ordinates of curved lines. He proposed the famous Fermat's Last Theorem while studying the work of the ancient Greek mathematician Diophantus. He wrote in pencil in the margin, "I have discovered a truly remarkable proof which this margin is too small to contain," that when the Pythagorean theorem is altered to read an + bn = cn, the new equation cannot be solved in integers for any value of n greater than 2. *TIS

1954 Ingrid Daubechies ( born 17 August 1954) is a Belgian physicist and mathematician. She is currently Professor in the mathematics and applied mathematics departments at Princeton University. In January 2011 she moved to Duke University as a Professor in mathematics. She is the first woman president of the International Mathematical Union (2011–2014). She is best known for her work with wavelets in image compression.*Wik

DEATHS
1786 Death of Frederick the Great. Euler's interest in lotteries began at the latest in 1749 when he was commissioned by Frederick the Great to render an opinion on a proposed lottery. The first of two letters began 15 September 1749. A second series began on 17 August 1763.

1924 1898 Pavel Samuilovich Urysohn, Pavel Uryson (February 3, 1898, Odessa – August 17, 1924, Batz-sur-Mer) is best known for his contributions in the theory of dimension, and for developing Urysohn's Metrization Theorem and Urysohn's Lemma, both of which are fundamental results in topology. His name is also commemorated in the term Menger-Urysohn dimension and in the term Urysohn integral equation. The modern definition of compactness was given by him and Pavel Alexandrov in 1923.*Wik

1927 (Erik) Ivar Fredholm (7 Apr 1866,17 Aug 1927) Swedish mathematician who founded modern integral equation theory. *TIS

1969 Otto Stern (17 Feb 1888; 17 Aug 1969 at age 81) German-American scientist and winner of the Nobel Prize for Physics in 1943 for his development of the molecular beam as a tool for studying the characteristics of molecules and for his measurement of the magnetic moment of the proton. *TIS

Credits
*VFR = V Frederick Rickey, USMA
*TIS= Today in Science History
*Wik = Wikipedia
*SAU=St Andrews Univ. Math History
*CHM=Computer History Museum