**God is a child; and when he began to play, he cultivated mathematics.**

**It is the most godly of man's games.**

The 260th day of the year; 260 is the constant for each row, column and diagonal of an 8x8 magic square. It is also the sum of the squares of the divisors of 15. The 8x8 is the smallest order for a bimagic square (the squares of the numbers also form a magic square) that uses consecutive digits.The constant for the magic square formed by the squares is 11,180. More on the first of these in 1891 at the Feb 1 On This Day in Math.

In

**1683**, the Dutch scientist Antonie van Leeuwenhoek wrote to the Royal Society reporting his discovery of microscopic living animalcules (live bacteria). He had made observations on the plaque between his own teeth, "a little white matter, which is as thick as if 'twere batter." Looking at these samples with his microscope, Leeuwenhoek reported how in his own mouth: "I then most always saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving. The biggest sort. . . had a very strong and swift motion, and shot through the water (or spittle) like a pike does through the water. The second sort. . .oft-times spun round like a top. . . and these were far more in number." *TIS

**1787**U.S. Constitution signed. Its format was inﬂuenced by the axiomatic approach of Euclidean Geometry. *VFR (

*I would appreciate insight into what this means? comments? Suggestions? Wild guesses?*)

**1871**Opening of the Mount Cenis (Fréjus) Tunnel (1857-70) through the Alps, the world's first important mountain tunnel. The two track railway tunnel unites Italian Savoy (north of the mountains) through Switzerland with the rest of Italy to the south. At 8 miles long and it was more than double the length of any previous tunnel. In 1861, after three years of tedious hand-boring a mere eight inches a day into the rock face, Sommeiller introduced the first industrial-scale pneumatics for tunnel digging. He built a special reservoir, high above the tunnel entrance, to produce a head of water that compressed air (to 6 atm.) for pneumatic drills, able to dig up to 20 times faster. Authorized on 15 Aug 1857, the tunnel opened on 17 Sep 1871, as a major triumph of engineering.*TIS

1901 Peter Cooper Hewitt patents the first mercury-vapor lamp.Hewitt was issued U.S. patent #682692 on September 17, 1901. *Wik

**1971**RCA withdraws from computer market, losing $490M *CHM

**1985**The Los Angeles Times reported that scientists at Chevron tested their new $10 million Cray XMP supercomputer and discovered the 30

^{th}Mersenne Prime and largest known prime (

*to that date*), 2

^{216}− 1

*[Part I, pp. 3, 19; Mathematics Magazine

**2008**, On September 17, a team of researchers at the University of Texas at Dallas led by Founders Professor Hal Sudborough announced the acceptance by the journal Theoretical Computer Science of a more efficient algorithm for pancake sorting than the one proposed by Gates and Papadimitriou in 1979. This establishes a new upper bound of (18/11)n, improving upon the existing bound of (5/3)n from 1979 by William H Gates, soon to be known as Bill Gates of Microsoft, then a Sophomore student at Harvard. *wik

**1743 Marie Jean Antoine Nicolas de Caritat, marquis de Condorcet**(17 September 1743 – 28 March 1794), known as Nicolas de Condorcet, was a French philosopher, mathematician, and early political scientist whose Condorcet method in voting tally selects the candidate who would beat each of the other candidates in a run-off election. Unlike many of his contemporaries, he advocated a liberal economy, free and equal public education, constitutionalism, and equal rights for women and people of all races. His ideas and writings were said to embody the ideals of the Age of Enlightenment and rationalism, and remain influential to this day. He died a mysterious death in prison after a period of being a fugitive from French Revolutionary authorities.*Wik

**1764 John Goodricke**(17 Sep 1764; 20 Apr 1786) English astronomer who was the first to notice that some variable stars were periodic. Born a deaf-mute, after a proper education he was able to read lips and to speak. He was the first to calculate the period of Algol to 68 hours and 50 minutes, where the star was changing its brightness by more than a magnitude as seen from Earth. He was also first to correctly propose that the distant sun is periodically occulted by a dark body. John Goodricke was admitted to the Royal Society on 16 April 1786, when 21 years old. He didn't recognized this honor, because he died four days later, in York, from pneumonia.*TIS

**1826 (Georg Friedrich) Bernhard Riemann**(17 Sep 1826; 20 July 1866) was a German mathematician whose work widely influenced geometry and analysis. In addition, his ideas concerning geometry of space had a profound effect on the development of modern theoretical physics and provided the foundation for the concepts and methods used later in relativity theory. He clarified the notion of integral by defining what we now call the Riemann integral. He was an original thinker and a host of methods, theorems and concepts are named after him. Riemann suffered from tuberculosis and he spent his last years in Italy in an attempt to improve his health. *TIS (A nice cartoon about the Riemann Hypothesis)

**1846 Seth Carlo Chandler**(17 Sep 1846; 31 Dec 1913) an American astronomer best known for his discovery (1884-85) of the Chandler Wobble, a complex movement in the Earth's axis of rotation (now refered to as polar motion) that causes latitude to vary with a period of 14 months. His interests were much wider than this single subject, however, and he made substantial contributions to such diverse areas of astronomy as cataloging and monitoring variable stars, the independent discovery of the nova T Coronae, improving the estimate of the constant of aberration, and computing the orbital parameters of minor planets and comets. His publications totaled more than 200. *TIS

**1857 Konstantin Eduardovich Tsiolkovsky**(17 Sep 1857; 19 Sep 1935) Russian pioneer space theorist who, while a provincial Russian schoolteacher, worked out many of the principles of space travel. In 1883, he noted that vehicle in space would travel in the opposite direction to gas that it emitted, and was the first to seriously propose this method propulsion in space travel. He wrote various papers, including the 1903 article "Exploration of Space with Reactive Devices." The engineering equations he derived included parameters such as specific impulse, thrust coefficient and area ratio. He established that the most efficient chemical combination would be that of liquid hydrogen and liquid oxygen. He was later recognized by the Soviet Union as the "father of cosmonautics." He also built the first wind tunnel.*TIS

**1905 Hans Freudenthal**(September 17, 1905,– October 13, 1990) was a Dutch mathematician. He made substantial contributions to algebraic topology and also took an interest in literature, philosophy, history and mathematics education.

In 1937 he proved the Freudenthal suspension theorem.

Later in his life, Freudenthal focused on elementary mathematics education. In the 1970s, his single-handed intervention prevented the Netherlands from following the worldwide trend of "`new math"'. He was also a fervent critic of one of the first international school achievement studies.

In 1971 he founded the IOWO at Utrecht University, that after his death was renamed Freudenthal Institute, the current Freudenthal institute for science and mathematics education. He was awarded the Gouden Ganzenveer award in 1984, and died in Utrecht in 1990, sitting on a bench in a park where he always took a morning walk.*Wik

**1916 Oswald Garrison "Mike" Villard Jr**(17 Sep 1916; 7 Jan 2004) American electronics engineer who developed over-the-horizon radar (a way to detect objects out of direct sight by bouncing radar off the ionosphere, an electrically charged layer in the upper atmosphere) so radar could peer around the Earth's curvature to detect aircraft and missiles thousands of miles away. His interest in electricity began with a copy of Harper's Electricity Book for Boys. At age 12, he put together a radio from a kit. During WW II, he researched countermeasures to protect Allied forces against enemy radio and radar devices. He made pioneering studies of radar jamming. In 1947, he designed a simplified voice transmitter permitting two-way communication on a single radio channel, such as a telephone conversation. *TIS

**1934 Warren J. Mitofsky**, (17 September 1934 - 1 September 2006)While working at the Census Bureau in the 1960s, he and a colleague, Joseph Waksberg, began to devise a random-digit dialing (RDD) system that now bears both their names.

Mr. Mitofsky went to work at CBS News in 1967. Not long afterwards, he organized the first "exit poll" in a Kentucky gubernatorial election, with his first national exit poll being in 1972. He directed the CBS News Election and Survey Unit until 1990, leading, in 1975, to the joint effort with the NYTimes, the CBS News/New York

Times Poll (which The Times calls the New York Times/CBS News Poll),

which he directed until 1990.

Since 2003, Mitofsky, considered the "Father of Exit Polling" by many, led election-night analysis for the News Election Pool, providing exit-poll results and projections. (Mitofsky disliked the term "exit poll"; he preferred "Election Day survey".)

In exit polls on Election Day in 2004, Mitofsky's early exit polls found Senator John Kerry leading over President Bush, which led some in the news media to prepare for Senator Kerry becoming President Kerry. But such was too premature, as Mitofsky readily acknowledged, later discovering that the pro-Kerry exit-poll lead was caused by Republicans refusing to participate at a greater rate than Democrats in the exit polls. [Guess this shows the importance of not ignoring nonresponse.]

However, despite all this, Mitofsky will probably be best remembered by many for his efficient method of sampling telephone numbers using random-digit dialing (RDD), which is now known as the Mitofsky-Waksberg Method. In 1970, Mitofsky wrote an unpublished CBS News memorandum titled "Sampling of Telephone Households" that helped make his name a household word in public-opinion polling. Eight years later, Joseph Waksberg published an analogous paper, "Sampling Methods for Random Digit Dialing", in the prestigious Journal of the American Statistical Association (JASA), thus resulting in the Mitofsky-Waksberg Method appellation.

The Mitofsky-Waksberg Method of RDD is a cluster-sampling method

for sampling residential telephone numbers that greatly increases

the percentage of calls that do reach residential households. *David Bee

**1802 Baron Georg von Vega**(b. 1754- September 17, 1754), a military officer and mathematician famous for his military campaigns and his table of logarithms, was murdered for “his money and his watch.” [Eves, Adieu, 257◦] *VFR

**1823 Abraham-Louis Bréguet**(10 Jan 1747, 17 Sep 1823) Swiss-French horologist and inventor who became the leading French watchmaker of his time because of his artistic as well as technical skill. His innovations included a self-winding or "perpétuelle" watch (1780), the gong spring which decreased the size of repeater watches, and the first anti-shock device or "pare-chute", which improved the reliability of his watches while making them less fragile. In 1775 he founded the Breguet watchmaking firm. After a two year interruption during the French Revolution, he continued business with more inventions. He sold the first modern carriage clock to Bonaparte, and created the tact watch by which time could be read by touch.*TIS

**1877 William Fox Talbot**(11 Feb 1800, 17 Sep 1877) English mathematician, physicist, chemist who invented the negative-positive photographic process. He improved Thomas Wedgewood's discovery (1802) that brushing silver nitrate solution onto paper produces a light-sensitive medium able to record negative images, but Wedgewood was unable to control the darkening. In February 1835, Fox Talbot found that a strong solution of salt fixed the image. Using a camera obscura to focus an image onto his paper to produce a negative, then - by exposing a second sheet of paper to sunlight transmitted through the negative - he was the first to produce a positive picture of which he was able to make further copies at will. His Pencil of Nature (1844) was the first photographically illustrated book. *TIS

**1891 Józeph Miksa Petzval**(6 Jan 1807, 17 Sept 1891) worked for much of his life on the Laplace transform. He was influenced by the work of Liouville and wrote both a long paper and a two volume treatise on the Laplace transform and its application to ordinary linear differential equations. His study is thorough but not entirely satisfactory since he was unable to use contour integration to invert the transform.

But for a student of Petzval we might today call the Laplace transform the Petzval transform. Petzval fell out with this student who then accused Petzval of plagiarising Laplace's work. Although this was untrue, Boole and Poincaré, influenced no doubt by the quarrel, called the transformation the Laplace transform.

Petzval is best remembered for his work on optical lenses and lens aberration done in the early 1840's (Petzval curvature is named after him) which allowed the construction of modern cameras. Petzval produced an achromatic portrait lens that was vastly superior to the simple meniscus lens then in use. *SAU

**1908 Thomas E. Selfridge**, a 1903 classmate of Douglas MacArthur at West Point, whose tombstone at West Point reads “Gave up his life in the service of his country at Fort Myers, Virginia, September 17, 1908, falling with the ﬁrst government aeroplane.” The pilot, an Ohio bicycle maker named Orville Wright, survived. [Rick Atkinson, The Long Grey Line (1989), pp. 1–2] (

*His father was a general, but Selfridge Field, now an Air Natl. Guard base near Detroit, is named for the Lt.,the first person to die in a crash of a powered airplane.*)

**1999 Leonard Carlitz**(26 Dec 1907, 17 Sept 1999) Carlitz published 771 papers, supervised 44 doctoral and 51 master's theses. His major mathematical contributions are to finite field theory, number theory, and combinatorics. But his publications extend beyond these areas to include algebraic geometry, commutative rings and algebras, finite differences, geometry, linear algebra, and special functions.*SAU

Credits :

*CHM=Computer History Museum

*FFF=Kane, Famous First Facts

*NSEC= NASA Solar Eclipse Calendar

*RMAT= The Renaissance Mathematicus, Thony Christie

*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