**We have a habit in writing articles published in scientific journals to make the work as finished as possible, to cover up all the tracks, to not worry about the blind alleys or describe how you had the wrong idea first, and so on. So there isn't any place to publish, in a dignified manner, what you actually did in order to get to do the work.**

~Feynman, Richard Philips Nobel Lecture, 1966.

The 266th day of the year; 266 can be expressed as 222 in base 11.

266 is the sum of four cubes, It is also the index of the largest proper subgroups of the sporadic group known as the Janko group

*J*

_{1 }

266 is the sum of five consecutive Triangular numbers. 15 + 21 + 28 + 36 + 45 + 55 + 66. On Sept , 1796 Gauss's entry "EγPHKA! num=Δ+Δ+Δ" in his scientiﬁc diary, recording his discovery that every positive integer is the sum of (at most) three triangular numbers. Can you find three for 266? Can you find three or less in more than one way?

266 has a digit sum of 12, a divisor of 266, so it is a Joy-Giver number.

The sum of the divisors of 266 is 18^2 = 324.

Many people know that N! has N digits for N= 22, 23, and 24. Surprisingly, to me, there are also three consecutive numbers for which N! has 2N digits, 266, 267, and 268. For N! has 3N digits, only two consecutive numbers, 2712 and 2713.For N! having 4N digits, there are again two consecutive occurrences, 27175 and 27176. For 5N we go back to three consecutive digits, 271819, 271820, 271821 Note the increase by a power of ten as a limit, and the higher you go, the closer they approach e * 10^n. It has been conjectured that there are always at two or three consecutive numbers for every digit, but never more. The first 100 such numbers are found at A058814 - OEIS Thanks to Derek Orr and Frank Kampas for some help and direction on this.

**1574**Tycho Brahe's rising fame while he lived in Copenhagen brings unwanted lecturing demands. In the capital his rising fame had attracted considerable attention, and some young nobles who were studying at the University requested him to deliver a course of lectures on some mathematical subject on which there were no lectures being given at that time. His friends Dancey and Pratensis urged him to consent to this proposal, but Tycho was not inclined to do so, until the King had also requested him to gratify the wishes of the students. He then yielded, and the lectures were commenced on the 23rd of September 1574, with an oration on the antiquity and importance of the mathematical sciences. *TYCHO BRAHE, A PICTURE OF SCIENTIFIC LIFE AND WORK IN THE SIXTEENTH CENTURY BY J. L. E. DREYER

**1647**Descartes, on a visit on September 23-24 to France from Holland, met with Pascal. On this occasion Descartes may have recommended the experiment of noting the variation in the height of the barometer with altitude. [J. F. Scott, The Scientiﬁc Work of Ren´e Descartes, p. 6] *VFR

His visit only lasted two days and the two argued about the vacuum which Descartes did not believe in. Pascal had done a series of experiments on atmospheric pressure and proved to his satisfaction that a vacuum existed.Descartes wrote, rather cruelly, in a letter to Huygens after this visit that Pascal, " ...has too much vacuum in his head. " *SAU

Also present were Professor Roberval, of the College de France, a voluble anti-Cartesian, and Pascal's younger sister Jacqueline. Pascal brought out a calculating machine, his recent invention, and demonstrated its ability to add and subtract. Descartes was impressed. The talk turned to the vacuum. Pascal described his experiment; Descartes expressed doubt - a polite skirmish that might have ended there. But Roberval injected his opinion, and a heated argument ensued. Descartes took his leave.*The Independent UK, Saturday 15 June 1996

The next morning, however, he returned - not Descartes the philosopher this time, but Descartes the physician. He sat for three hours by his patient's side, listened to his complaints, examined him, prescribed soups and rest. When Pascal was sick of staying in bed, Descartes said, he would be nearly well. Their views would remain opposed, but it was the supreme rationalist in his role as kindly doctor whom Pascal would later remember, and who may have been in his mind when he observed, "The heart has its reasons which reason knows nothing of"

The Pascaline, also called Arithmetic Machine, the first calculator or adding machine to be produced in any quantity and actually used. It was built by Blaise Pascal between 1642 and 1644. It could only do addition and subtraction, with numbers being entered by manipulating its dials. Pascal invented the machine for his father, a tax collector, so it was the first business machine too (if one does not count the abacus). He built 50 of them over the next 10 years.

1673 Hooke in his diary, "bought Pappus in Cornhill for 11sh. at ye crown." *Robert Hooke @HookesLondon

Suspect but am not sure that this was Commandino's translation of Pappus's Mathematicae Collectiones

**1763**The Princess Louise sailed for Barbados on 23 September. During the voyage Maskelyne and Charles Green took many lunar-distance observations (with Maskelyne later claiming that his final observation was within half of degree of the truth) and struggled a couple of times with the marine chair. Maskelyne’s conclusion was that the Jupiter’s satellites method of finding longitude would simply never work at sea because the telescope magnification required was far too high for use in a moving ship.

On 29 December 1763 he wrote his brother Edmund, reporting his safe arrival on 7 November after “an agreeable passage of 6 weeks”. He noted that he had been “very sufficiently employed in making the observations recommended to me by the Commissioners of Longitude” and that it was at times “rather too fatiguing”. *Board of Longitude project, Greenwich

A marine chair made by Christopher Irwin that was intended to steady an observer to allow him to measure the positions of Jupiter's satellites at sea. (Eclipses of Jupiter's moons were already used as a celestial timekeeper to determine longitude on land: these were the observations Maskelyne made at Barbados.)

1740 In a letter to Euler dated August 29th, 1740, Philippe Naudé (the Younger) asked Euler in how many ways a number n can be written as a sum of positive integers. In his answer written on September 12th (23rd), Euler explained that if we denote

this “partition number” by p(n), then

*Correspondence of Leonhard Euler with Christian Goldbach, Springer

1793 The new decimalized calendar was presented to the Jacobin-controlled National Convention on 23 September 1793, which adopted it on 24 October 1793 and also extended it proleptically to its epoch of 22 September 1792. The French Republican Calendar was a calendar created and implemented during the French Revolution, and used by the French government for about 12 years from late 1793 to 1805, and for 18 days by the Paris Commune in 1871. There were twelve months (??? Why, with all this decimalation, not go all the way with ten months), each divided into three ten-day weeks called décades. The tenth day, décadi, replaced Sunday as the day of rest and festivity. The five or six extra days needed to approximate the solar or tropical year were placed after the months at the end of each year. The new system was designed in part to remove all religious and royalist influences from the calendar, and was part of a larger attempt at decimalisation in France. *Wik

The Months of the French Decimal Calendar

Autumn:

Vendémiaire (from French vendange, derived from Latin vindemia, "vintage"), starting 22, 23, or 24 September

Brumaire (from French brume, "mist", from Latin brūma, "winter solstice; winter; winter cold"), starting 22, 23, or 24 October

Frimaire (from French frimas, "frost"), starting 21, 22, or 23 November

Winter:

Nivôse (from Latin nivosus, "snowy"), starting 21, 22, or 23 December

Pluviôse (from French pluvieux, derived from Latin pluvius, "rainy"), starting 20, 21, or 22 January

Ventôse (from French venteux, derived from Latin ventosus, "windy"), starting 19, 20, or 21 February

Spring:

Germinal (from French germination), starting 21 or 22 March

Floréal (from French fleur, derived from Latin flos, "flower"), starting 20 or 21 April

Prairial (from French prairie, "meadow"), starting 20 or 21 May

Summer:

Messidor (from Latin messis, "harvest"), starting 19 or 20 June

Thermidor (or Fervidor*) (from Greek thermon, "summer heat"), starting 19 or 20 July

Fructidor (from Latin fructus, "fruit"), starting 18 or 19 August

**1815**The Great September Gale of 1815 came ashore in New England on this date. This was the first hurricane, although the word had not been created yet, to hit New England in 180 yrs. In the aftermath of the Great Gale, the concept of a hurricane as a "moving vortex" was presented by John Farrar, Hollis Professor of Mathematics and Natural Philosophy at Harvard University. In an 1819 paper he concluded that the storm "appears to have been a moving vortex and not the rushing forward of a great body of the atmosphere". The word "hurricane" comes from Spanish huracán, from the Taino hurakán, “god of the storm.” While the Taino have been essentially wiped out by disease brought by the Spanish, there are still several words from the language remaining in English. Two of my favorites, Barbecue and Hammock. *Assorted sources (

*The Merriem Webster gives the first use of Hurricane in 1555, the same year as another Taino word, Yuca, was first used in English.*)

*Engraving: The Great Storm of 1815 strikes Providence, Rhode Island. From an old painting in possession of the Rhode Island Historical Society.*

**1831**Faraday writes to Richard Phillips, “ I am busy just now again on Electro-Magnetism and think I have got hold of a good thing but can't say; it may be a weed instead of a fish that after all my labour I may at last pull up.” (It was a fish Michael!) * Michael Faraday, Bence Jones (ed.), The Life and Letters of Faraday (1870), Vol. 2, 3

One of Faraday's 1831 experiments demonstrating induction. The liquid battery (right) sends an electric current through the small coil (A). When it is moved in or out of the large coil (B), its magnetic field induces a momentary voltage in the coil, which is detected by the galvanometer (G).

*Wik |

**1846**Neptune first seen. Le Verrier's most famous achievement is his prediction of the existence of the then unknown planet Neptune, using only mathematics and astronomical observations of the known planet Uranus. Encouraged by physicist Arago, Director of the Paris Observatory, Le Verrier was intensely engaged for months in complex calculations to explain small but systematic discrepancies between Uranus's observed orbit and the one predicted from the laws of gravity of Newton. At the same time, but unknown to Le Verrier, similar calculations were made by John Couch Adams in England. Le Verrier announced his final predicted position for Uranus's unseen perturbing planet publicly to the French Academy on 31 August 1846, two days before Adams's final solution, which turned out to be 12° off the mark, was privately mailed to the Royal Greenwich Observatory. Le Verrier transmitted his own prediction by 18 September letter to Johann Galle of the Berlin Observatory. The letter arrived five days later, and the planet was found with the Berlin Fraunhofer refractor that same evening, 23 September 1846, by Galle and Heinrich d'Arrest within 1° of the predicted location near the boundary between Capricorn and Aquarius. Le Verrier will be known by the phrase attributed to Arago: "the man who discovered a planet with the point of his pen." [Le Verrier also noted that the perihelion of Mercury was advancing more rapidly than Newtonian physics could account for, but he proposed in 1845 that this was due to a planet between Mercury and the sun which he called Vulcan…..oops] *Wik (

*It is a strange twist of fate that he died on the date on which his most famous prediction was verified, See below under deaths*)(Another coincidence is that the Director of the Berlin Observatory where Galle observed the new planet, was Johann Encke, whose birth was on this date. One story says he wasn't interested in the proposed planet, but yielded to Galle's request to seek it out because Encke was hurrying home for a birthday celebration.)

Within 17 days of the discovery of Neptune, William Lassell of Liverpool would discover the planet's largest moon, to be named Triton, on October 10.

Berlin Fraunhofer refractor |

**1884**Patent ﬁled for Hollerith tabulating machine. It was used in the 1890 census and became the model for computer cards. *VFR

The tabulating machine was an electromechanical machine designed to assist in summarizing information stored on punched cards. Invented by Herman Hollerith.

*Wik *CHM |

**1983**The Los Angeles Times reported that David Slowinski of Cray research has found the 29th Mersenne prime, 2

^{132,049}-1. It turned out that this was actually the 30th, as the 29th would turn out to be 2

^{110,503}-1 found by Walter Colquitt ; Luke Welsh almost five years later on Jan 28, 1988 *VFR & Wik

**1623 Stefano degli Angeli**(Venice, September 23, 1623 – Padova, October 11, 1697) was an Italian mathematician, philosopher, and Jesuate.

He was member of the Catholic Order of the Jesuats (Jesuati). In 1668 the order was suppressed by Pope Clement IX. Angeli was a student of Bonaventura Cavalieri. From 1662 until his death he taught at the University of Padua.

From 1654 to 1667 he devoted himself to the study of geometry, continuing the research of Cavalieri and Evangelista Torricelli based on the method of Indivisibles. He then moved on to mechanics, where he often found himself in conflict with Giovanni Alfonso Borelli and Giovanni Riccioli.

Showing an early interest in mathematics and the concept of infinitesimals, Angeli studied and wrote on the behavior of various curves and physical applications of mathematics. In his Accessionis ad Stereometriam et Mecanicam (1662), he examined various solids and determined their centers of gravity.

**1768 William Wallace**(23 September 1768, Dysart in Fife – 28 April 1843, Edinburgh) was a Scottish mathematician and astronomer who invented the eidograph. (A form of pantograph for reproducing images on a different scale) He mainly worked in the field of geometry and in 1799 became the first to publish the concept of the Simson line, which erroneously was attributed to Robert Simson by Poncelet. In 1807 he proved a result about polygons with an equal area, that later became known as the Bolyai–Gerwien theorem. His most important contribution to British mathematics however was, that he was one of the first mathematicians introducing and promoting the advancement of the continental European version of calculus in Britain.

Wallace's grave in Greyfriars Kirkyard, Edinburgh, 2012 |

He developed a reputation for being an excellent teacher. Among his students was Mary Somerville. In 1838 he retired from the university due to ill health. He died in Edinburgh and is buried in Greyfriars Churchyard. *Wik

"There was an especially active period of invention in Scotland in the 1820s when heated controversy surrounded instruments such as Andrew Smith’s apograph and his “new” pantograph, as well as John Dunn’s pantograph. The most successful and long-lived of these new designs was the eidograph devised by the Edinburgh professor of mathematics William Wallace in 1821. Like the pantograph, the eidograph incorporated tracing, drawing, and fixed points, all three of which remained in a single line during operation. However Wallace’s arrangement of these components was novel. The fixed weight was placed centrally and supported a graduated bar at each end of which was a pivoted, adjustable rod, one bearing the tracer and the other the drawing point. A fine chain (later a steel band) was used to link the two rods and ensure that they moved in parallel. Wallace was able to dispense with the pantograph’s castors because his instrument was balanced around the central weight. At the time Wallace was working on the eidograph, Edinburgh was a center for publishing and engraving, and among its characteristic products were multivolume encyclopedias. These were expected to be heavily illustrated with engraved plates whose images would usually be copied from existing publications. Al-though it was never developed commercially, Wallace devised a special form of eidograph to produce reversed images that were engraved directly onto copper plates for printing. The simpler form of eidograph was manufactured by the London maker Robert Bate and then, in a reengineered version, by Alexander Adie. It was further improved by W.F. Stanley in the second half of the nineteenth century and, in parallel with the pantograph, continued to figure in instrument makers’ catalogs into the twentieth century."

(Ref: Bud J. & Warner D.J. (Ed). Instruments of Science – An Historical Encyclopedia. The Science Museum, London and The National Museum of American History, 1998.)

The Eidograph (sometimes ideograph) is from the same Greek root as Idol. The reproduced image is called an eidolan.

^{}

**1785**Georg Scheutz (1785-1873), who with his son built a commercially available calculator based on Charles Babbage's Difference Engine, is born in Stockholm. After reading about the Difference Engine in 1833, Scheutz and son Edvard worked on a version that could process 15-digit numbers and calculate using fourth-order differences. In 1851 they obtained funds from government to build an improved model, which was created in 1853 (was roughly the size of a piano), and subsequently demonstrated at the World's Fair in Paris, 1855. The result won the gold medal at the Paris Exhibition in 1855 and was used by the Dudley Observatory in New York to calculate a few tables. A second copy was used by the British Registrar General to calculate tables for the developing life insurance industry. *CHM

**1791 Johann Franz Encke**(23 Sep 1791; 26 Aug 1865) German astronomer who in 1819 established the period of the comet now known by as Encke's Comet. At at 3.3 years it has the shortest period of any known. *TIS It was first recorded by Pierre Méchain in 1786, but it was not recognized as a periodic comet until 1819 when its orbit was computed by Encke. Comet Encke is believed to be the originator of several related meteor showers known as the Taurids (which are encountered as the Northern and Southern Taurids across November, and the Beta Taurids in late June and early July). Near-Earth object 2004 TG10 may be a fragment of Encke. Some also think it may have already had a part of it break off and hit the earth. "In 1908 Comet Encke was making a close pass near the Earth. It is believed that a 100 meter (m) diameter chunk of ice from Encke broke off and plowed into the atmosphere over the Stony Tunguska River in Siberia. The result was an air-burst explosion liberating the equivalent of 600 Hiroshima-size nuclear bombs, so much energy that sensitive instruments around the world recorded the resulting shock waves. Trees in the Siberian forests were leveled for dozens of miles around, and horses 400 miles away were knocked from their feet. There was no known loss of human life, but this is only because the impact site was so isolated. If the same ice chunk had, by chance, struck over a major population center, Tokyo, or New York, or Bombay, mega-deaths would have resulted. " *greatdreams.com

Encke might well have been the first to observe Neptune, but it was his birthdate, and so he left it to Galle to seek it out and went home to a birthday celebration.

**1819 Armand-Hippolyte-Louis Fizeau**(23 Sep 1819; 18 Sep 1896) French physicist who was the first to measure the speed of light successfully without using astronomical calculations (1849). Fizeau sent a narrow beam of light between gear teeth on the edge of a rotating wheel. The beam then traveled to a mirror 8 km/5 mi away and returned to the wheel where, if the spin were fast enough, a tooth would block the light. Knowing this time from the rotational speed of the wheel, and the mirror's distance, Fizeau directly measured the speed of light. He also found that light travels faster in air than in water, which confirmed the wave theory of light, and that the motion of a star affects the position of the lines in its spectrum. With Jean Foucault, he proved the wave nature of the Sun's heat rays by showing their interference (1847).*TIS

**1851 Ellen Amanda Hayes**(September 23, 1851 – October 27, 1930) was an American mathematician and astronomer. Born in Granville, Ohio (

*pop 1,127 in the 1880 census*) she graduated from Oberlin College in 1878 and began teaching at Adrian College. From 1879 to her 1916 retirement, she taught at Wellesley College, where she became head of the mathematics department in 1888 and head of the new department in applied mathematics in 1897.Hayes was also active in astronomy, determining the orbit of newly discovered 267 Tirza while studying at the Leander McCormick Observatory at the University of Virginia.

She wrote a number of mathematics textbooks. She also wrote Wild Turkeys and Tallow Candles (1920), an account of life in Granville, and The Sycamore Trail (1929), a historical novel.

Hayes was a controversial figure not just for being a rare female mathematics professor in 19th century America, but for her embrace of radical causes like questioning the Bible and gender clothing conventions, suffrage, temperance, socialism, the 1912 Lawrence Textile Strike, and Sacco and Vanzetti. She was the Socialist Party candidate for Massachusetts Secretary of State in 1912, the first woman in state history to run for statewide office. She did not win the race, but did receive more votes than any Socialist candidate on the ballot, including 2500 more than their gubernatorial candidate.

Hayes was concerned about under-representation of women in mathematics and science and argued that this was due to social pressure and the emphasis on female appearance, the lack of employment opportunities in those fields for women, and schools which allowed female students to opt out of math and science courses.

Her will left her brain to the Wilder Brain Collection at Cornell University. Her ashes were buried in Granville, Ohio. *Wik

**1869 Typhoid Mary Mallon**(23 Sep 1869; 11 Nov 1938) famous typhoid carrier in the New York City area in the early 20th century. Fifty-one original cases of typhoid and three deaths were directly attributed to her (countless more were indirectly attributed), although she herself was immune to the typhoid bacillus (Salmonella typhi). The outbreak of Typhus in Oyster Bay, Long Island, in 1904 puzzled the scientists of the time because they thought they had wiped out the deadly disease. Mallon's case showed that a person could be a carrier without showing any outward signs of being sick, and it led to most of the Health Code laws on the books today. She died not from typhoid but from the effects of a paralytic stroke dating back to 25 Dec 1932.*TIS

**1921 Albert Messiah**(23 September 1921, Nice – 17 April 2013, Paris) was a French physicist.

He spent the Second World War in the French Resistance: he embarked June 22, 1940 in Saint-Jean-de-Luz to England and participated in the Battle of Dakar with Charles de Gaulle in September 1940. He joined the Free French Forces in Chad, and the 2nd Armored Division in September 1944, and participated in the assault of Hitler's Eagle's nest at Berchtesgaden in 1945.

After the war, he went to Princeton to attend the seminar of Niels Bohr on quantum mechanics. He returned to France and introduced the first general courses of quantum mechanics in France, at the University of Orsay. His textbook on quantum mechanics (Dunod 1959) has trained generations of French physicists.

He was the director of the Physics Division at the CEA and professor at the Pierre and Marie Curie University. *Wik

**1968 Wendelin Werner**(September 23, 1968 - ) is a German-born French mathematician working in the area of self-avoiding random walks, Schramm-Loewner evolution, and related theories in probability theory and mathematical physics. In 2006, at the 25th International Congress of Mathematicians in Madrid, Spain he received the Fields Medal. He is currently Rouse Ball professor of Mathematics at the University of Cambridge.

Werner has received several awards besides the Fields Medal, including the Rollo Davidson Prize in 1998, the Prix Paul Doistau–Émile Blutet in 1999, the Fermat Prize in 2001, the Grand Prix Jacques Herbrand of the French Academy of Sciences in 2003, the Loève Prize in 2005, the 2006 SIAM George Pólya Prize with his collaborators Gregory Lawler and Oded Schramm, and the Heinz Gumin Prize (de) in 2016.*Wik

**1657 Joachim Jungius**was a German mathematician who was one of the first to use exponents to represent powers and who used mathematics as a model for the natural sciences. *SAU

In 1669, Jungius demonstrated that the form adopted by the chain wasn’t a parabola and one year later, Jakob Bernoulli (1654-1705) proposed a contest looking for the first mathematician who could find out the real forma of a hanging chain. The problem was solved by Johann Bernoulli (1667-1748), Christiann Huygens (1629-1695) and Gottfried W. Leibnitz (1646-1717) each independently.

**1877 Urbain-Jean-Joseph Le Verrier**(11 Mar 1811; 23 Sep 1877 at age 66) French astronomer who predicted by mathematical means the existence of the planet Neptune. He switched from his first subject of chemistry to to teach astronomy at the Ecole Polytechnique in 1837 and worked at the Paris Observatory for most of his life. His main activity was in celestial mechanics. Independently of Adams, Le Verrier calculated the position of Neptune from irregularities in Uranus's orbit. As one of his colleagues said, " ... he discovered a star with the tip of his pen, without any instruments other than the strength of his calculations alone. In 1856, the German astronomer Johan G. Galle discovered Neptune after only an hour of searching, within one degree of the position that had been computed by Le Verrier, who had asked him to look for it there. In this way Le Verrier gave the most striking confirmation of the theory of gravitation propounded by Newton. Le Verrier also initiated the meteorological service for France, especially the weather warnings for seaports. Incorrectly, he predicted a planet, Vulcan, or asteroid belt, within the orbit of Mercury to account for an observed discrepancy (1855) in the motion in the perihelion of Mercury. *TIS

This statue depicts Le Verrier, who was well known for discovering Neptune, this sculpture created by Henri Michel Antoine Chapu and can be found in front of Observatoire de Paris.

1822 Joseph-Louis-François Bertrand (11 Mar 1822; 5 Apr 1900 at age 78) was a French mathematician and educator and educator remembered for his elegant applications of differential equations to analytical mechanics, particularly in thermodynamics, and for his work on statistical probability and the theory of curves and surfaces. In 1845 Bertrand conjectured that there is at least one prime between n and (2n-2) for every n>3, as proved five years later by Chebyshev. In 1855 he translated Gauss's work on the theory of errors and the method of least squares into French. He wrote a number of notes on the reduction of data from observations. *TIS At age 11 he started to attend classes at the Ecole Polytechnique, where his Uncle Duhamel was a well-known professor of mathematics. At 17 he received his doctor of science degree. *VFR

**1897 “Bourbaki**is a pen name of a group of younger French mathematicians who set out to publish an encyclopedic work covering most of modern mathematics.” So wrote Samuel Eilenberg in Mathematical Reviews, 3(1942), 55–56. He was the ﬁrst to reveal in print that Bourbaki was a pseudonym—but the name was appropriated from a real general, Charles Denis Sauter Bourbaki, who died on this date at the age of 81. See Joong Fang, Bourbaki, Paideia Press, 1970, pp. 24, *VFR

**1919 Heinrich Bruns**was interested in astronomy, mathematics and geodesy and worked on the three body problem.*SAU

**1971 James Waddell Alexander**(19 Sept 1888, 23 Sept 1971) In a collaboration with Veblen, he showed that the topology of manifolds could be extended to polyhedra. Before 1920 he had shown that the homology of a simplicial complex is a topological invariant. Alexander's work around this time went a long way to put the intuitive ideas of Poincaré on a more rigorous foundation. Also before 1920 Alexander had made fundamental contributions to the theory of algebraic surfaces and to the study of Cremona transformations.

Soon after arriving in Princeton, Alexander generalised the Jordan curve theorem and continued his work, now exclusively on topology, with an important paper on the Jordan-Brouwer separation theorem. This latter paper contains the Alexander Duality Theorem and Alexander's lemma on the n-sphere. In 1924 he introduced the now famous Alexander horned sphere.

In 1928 he discovered the Alexander polynomial which is much used in knot theory. In the same year the American Mathematical Society awarded Alexander the Bôcher Prize for his memoir, Combinatorial analysis situs published in the Transactions of the American Mathematical Society two years earlier. Knot theory and the combinatorial theory of complexes were the main topics on which he worked over the following few years.

The theory which is now called the Alexander-Spanier cohomology theory, was introduced in 1935 by Alexander but was generalised by Spanier in 1948 to the form seen today. Also around 1935 Alexander discovered cohomology theory, at essentially the same time as Kolmogorov, and the theory was announced in the 1936 Moscow Conference. *SAU

**2004 Bryce Seligman DeWitt**(January 8, 1923 – September 23, 2004) was a theoretical physicist who studied gravity and field theories.

He approached the quantization of general relativity, in particular, developed canonical quantum gravity and manifestly covariant methods that use the heat kernel. B. DeWitt formulated the Wheeler–DeWitt equation for the wavefunction of the Universe with John Archibald Wheeler and advanced the formulation of the Hugh Everett's many-worlds interpretation of quantum mechanics. With his student Larry Smarr he originated the field of numerical relativity.

He received his bachelor's, master's and doctoral degrees from Harvard University. His Ph.D. (1950) supervisor was Julian S. Schwinger. Afterwards he worked at the Institute for Advanced Study, the University of North Carolina at Chapel Hill and the University of Texas at Austin. He was awarded the Dirac Prize in 1987, the American Physical Society's Einstein Prize in 2005, and was a member of the National Academy of Sciences and the American Academy of Arts and Letters.

He was born Carl Bryce Seligman but he and his three brothers added "DeWitt" from their mother's side of the family, at the urging of their father, in 1950. This is similar to Spanish naming customs, where a person bears two surnames, one being from their father and the other from their mother. Twenty years later this change of name so angered Felix Bloch that he blocked DeWitt's appointment to Stanford University and DeWitt instead moved to Austin, Texas. He served in World War II as a naval aviator. He was married to mathematical physicist Cécile DeWitt-Morette. He died September 23, 2004 from pancreatic cancer at the age of 81. He is buried in France, and was survived by his wife and four daughters. *Wik

Bryce with his wife Cécile

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

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