**Mankind will not remain on the earth forever, but, in search of light and space, will at first timidly penetrate beyond the limits of the atmosphere and then finally conquer the spaces of the solar system.**

— Konstantin Eduardovich Tsiolkovsky

tombstone inscription

The 263rd day of the year; 263 is an irregular prime. (an odd prime which divides the numerator of a Bernoulli Number) They became of great interest after 1850 when Kummer proved that Fermat's Last Theorem was true for any exponent that was a regular prime.

**1648**The theory of atmospheric pressure and the existence of a vacuum were conﬁrmed by experiments designed by Blaise Pascal.*VFR

**1783**The brothers Montgolﬁer repeated their experiment of 4 June 1783, in the presence of Louis XVI at Versailles. At one o’clock the crowd went wild as the balloon soared gracefully free carrying a rooster, a sheep, and a duck.*VFR

In

**1848**, Hyperion, moon of Saturn, discovered by William Cranch Bond(US), George Phillips Bond(US) and William Lassell(UK)*TIS It was the first non-round moon to be discovered. Hyperion's discovery came shortly after John Herschel had suggested names for the seven previously-known satellites of Saturn in his 1847 publication Results of Astronomical Observations made at the Cape of Good Hope. Lassell, who saw Hyperion two days after William Bond, had already endorsed Herschel's naming scheme and suggested the name Hyperion in accordance with it. He also beat Bond to publication. *Wik

**1894**In a letter to Felix Klein (19 September 1894) Peano wrote: “The purpose of mathematical logic is to analyze the ideas and reasoning that especially figure in the mathematical sciences.” Peano was neither a logicist nor a formalist. He believed rather that mathematical ideas are ultimately derived from our experience of the material world. *Hubert Kennedy, "Eight Mathematical Biographies" Pg 27

**1994**Andrew Wiles has an "AHA" moment, Over the course of three lectures delivered at Isaac Newton Institute for Mathematical Sciences on June 21, 22, and 23 of 1993, Wiles had announced his proof of the Taniyama–Shimura conjecture, and hence of Fermat's Last Theorem. There was a relatively large amount of press coverage afterwards.

After announcing his results, (Nick) Katz was a referee on his manuscript and he asked Wiles a series of questions that led Wiles to recognize that the proof contained a gap. There was an error in a critical portion of the proof which gave a bound for the order of a particular group: the Euler system used to extend Flach's method was incomplete. Wiles and his former student Richard Taylor spent almost a year resolving it. Wiles indicates that on the morning of September 19, 1994 he realized that the specific reason why the Flach approach would not work directly suggested a new approach with the Iwasawa theory which resolved all of the previous issues with the latter and resulted in a CNF that was valid for all of the required cases. On 6 October Wiles sent the new proof to three colleagues including Faltings. The new proof was published and, despite its size, widely accepted as likely correct in its major components. *Wik

1995 Ahoy Matey, International "Talk Like a Pirate Day is born" is a parodic holiday created in 1995 by John Baur (Ol' Chumbucket) and Mark Summers (Cap'n Slappy), of Albany, Oregon

^{}, who proclaimed September 19th each year as the day when everyone in the world should talk like a pirate.

^{ }For example, an observer of this holiday would greet friends not with "Hello," but with "Ahoy, matey!" The holiday, and its observance, springs from a romanticized view of the Golden Age of Piracy. *Wik

**2009**at the autumn meeting of the British Society for the History of Mathematics (BSHM), The Archimedes Codex by Reviel Netz and William Noel was awarded the Neumann Prize for the best book in the history of mathematics aimed a broad audience. Reviel Netz is Professor of Classics at Stanford University, California, and Dr William Noel is the curator of manuscripts and rare books at The Walters Art Museum in Baltimore, Maryland.

The prize was awarded for the first time this year and will henceforth be bestowed every two years. The prize is named after Dr Peter Neumann, Emeritus Fellow of The Queen’s College, Oxford, and a former president of the BSHM. He was awarded the OBE in 2008 for his services to education.

The Archimedes Codex is a biography of one of the ancient world’s greatest mathematicians Archimedes of Syracuse (c.287 BC – c.212 BC) and tells the story of the rediscovery of a 10th-century copy of some of his writings and drawings, which were found hidden beneath a 13th-century prayer book. *History Today, September 23, 2009

**1749 Jean-Baptiste Joseph Delambre**(19 Sep 1749; 18 Aug 1822) He conducted a geodetic survey be-tween Dunkerque and Rodez which was instrumental in establishing the length of the meter. *VFR

**1840 John Emory McClintock**(19 Sept 1840 , 10 July 1916) for many years the leading actuary in America. He published 30 papers between 1868 and 1877 on actuarial questions. His publications were not confined to questions relating to life insurance policies however. He published about 22 papers on mathematical topics. One paper treats difference equations as differential equations of infinite order and others look at quintic equations which are soluble algebraically. He published A simplified solution of the cubic in 1900 in the Annals of Mathematics. Another work, On the nature and use of the functions employed in the recognition of quadratic residues (1902), published in the Transactions of the American Mathematical Society, is on quadratic residues.*SAU

**1888 James Waddell Alexander**(19 Sep 1888; 23 Sept 1971) American mathematician and a founder of the branch of mathematics originally known as analysis situs, now called topology. In 1912, he joined the faculty of the mathematics department at Princeton. Soon after, Alexander generalised the Jordan curve theorem and, in 1928, he discovered the Alexander polynomial which is much used in knot theory.*TIS

1908 Victor Frederick Weisskopf (September 19, 1908 – April 22, 2002) was an Austrian-born American theoretical physicist. He did postdoctoral work with Werner Heisenberg, Erwin Schrödinger, Wolfgang Pauli and Niels Bohr.[1] During World War II he worked at Los Alamos on the Manhattan Project to develop the atomic bomb, and later campaigned against the proliferation of nuclear weapons.

His brilliance in physics led to work with the great physicists exploring the atom, especially Niels Bohr, who mentored Weisskopf at his institute in Copenhagen. By the late 1930s, he realized that, as a Jew, he needed to get out of Europe. Bohr helped him find a position in the U.S.

In the 1930s and 1940s, 'Viki', as everyone called him, made major contributions to the development of quantum theory, especially in the area of Quantum Electrodynamics.[3] One of his few regrets was that his insecurity about his mathematical abilities may have cost him a Nobel prize when he did not publish results (which turned out to be correct) about what is now known as the Lamb shift. *Wik

1710 Olaus Roemer, Danish astronomer, born. He was the ﬁrst to measure the speed of light. *VFR (25 Sep 1644 - 23 Sep 1710) Astronomer who demonstrated conclusively that light travels at a finite speed. He measured the speed by precisely measuring the length of time between eclipses of Jupiter by one of its moons. This observation produces different results depending on the position of the earth in its orbit around the sun. He reasoned that meant light took longer to travel the greater distance when earth was traveling in its orbit away from Jupiter.*TIS

1761 Pieter van Musschenbroek (14 Mar 1692; 19 Sep 1761 at age 69) Dutch mathematician and physicist who invented the Leyden jar, the first effective device for storing static electricity. He grew up in a family that manufactured scientific instruments such as telescopes, microscopes and air pumps. Before Musschenbroek's invention, static electricity had been produced by Guericke using a sulphur ball, with minor effects. In Jan 1746, Musschenbroek placed water in a metal container suspended on silk cords, and led a brass wire through a cork into the water. He built up a charge in the water. When an unwary assistant touched the metal container and the brass wire, the discharge from this apparatus delivered a substantial shock of static electricity. The Leyden name is linked to the discovery having being made at the University of Leiden. *TIS

**1843 Gaspard Gustave de Coriolis**(21 May 1792, 19 Sept 1843) Coriolis is best remembered for the Coriolis force. He showed that the laws of motion could be used in a rotating frame of reference if an extra force called the Coriolis acceleration is added to the equations of motion. *SAU

**1935 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 (

*He is buried at the Park of the Cosmonauts' Museum, Kaluga Province, Russian Federation*)

**1968 Chester Floyd Carlson**(8 Feb 1906, 19 Sep 1968) American physicist who invented xerography (22 Oct 1938), an electrostatic dry-copying process that found applications ranging from office copying to reproducing out-of-print books. The process involved sensitizing a photoconductive surface to light by giving it an electrostatic charge Carlson developed it between 1934 and 1938, and initially described it as electrophotography It was immediately protected by Carlson with an impenetrable web of patents, though it was not until 1944 that he was able to obtain funding for further development. In 1947 he sold the commercial rights for his invention to the Haloid Company, a small manufacturer of photographic paper (which later became the Xerox Corporation).*TIS

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