Wednesday, 16 September 2026

On This Day in Math - September 17

 



God is a child; and when he began to play, he cultivated mathematics. 
It is the most godly of man's games.

~V Erath

The 260th day of the year; 260 is the constant for each row, column and diagonal of the first known(1891) 8x8 bimagic square.
The 8x8 is the smallest order possible 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.

260 is also the sum of the 8x8 pandiagonal square created by Emory McClintock in 1897.  A pandiagonal magic square, in addition to satisfying the requirement of a magic square, has the additional property that all diagonals, including broken diagonals, i.e. those that wrap around from one edge of the square to the opposite edge, add to the same sum. 


260 =66^2-64^2 , and also 16^2 + 2^2 = 4^4 + 4^1, and 14^2 + 8^2

260 is a Palindrome in base 8 (404)

The Mayan Sacred Calendar had a 260 year cycle. 


A 5x5 magic square with a constant of 260 can be formed by taking the standard 1-25 magic square and multiplying each term by four.  Another is to use 39, 40, 41,... , 64

260 is also the sum of the squares of the divisors of 15. /( 260 = 1^2 + 3^2 + 5^2 + 15^2 /)
See More Math Facts for every Year Day here



EVENTS


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?)The U.S. 

Constitution (1787) reflects axiomatic structure in the following ways:

Foundational Principles (like axioms):"We the People..." sets the source of authority.

The Preamble lays out fundamental goals (like the “why”).

Definitions of Powers and Terms:Articles I–III clearly define the roles and powers of the Legislative, Executive, and Judicial branches.

Systematic, Logical Order: The document proceeds from general principles to specific structures — just like a geometric treatise builds from axioms to propositions.

Checks and Balances (logical consistency):

Like Euclidean logic ensures no contradiction, the Constitution tries to balance powers to avoid internal contradiction in governance.




1789 William Herschel discovers the small moon Mimas, Saturns smallest and innermost moon.  The name of this, and the other six known moons of Saturn was suggested by William's son John in 1847.  All were named for mythological giants of Greek literature.  The large crater, now named for Herschel was not observed until photographed by the Cassinni probe on November 7, 2004.

*Tech Explorist



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

During the 2000s, the Fréjus Rail Tunnel underwent a series of works to modernise and improve it, including the increase of its bore to accommodate wider rail vehicles, such as container trucks on piggy-back wagons, as part of the Autoroute Ferroviaire Alpine. 

*Wik



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

In 1902, Hewitt developed the mercury arc rectifier, the first rectifier that could convert alternating current power to direct current without mechanical means. It was widely used in electric railways, industry, electroplating, and high-voltage direct current (HVDC) power transmission.

In 1907, he developed and tested an early hydrofoil. In 1916, Hewitt joined Elmer Sperry to develop the Hewitt-Sperry Automatic Airplane, one of the first successful precursors of the cruise missile. *Wik


1908  The Wright Flyer flown by Orville Wright, with Lieutenant Thomas Selfridge as passenger, crashes, killing Selfridge, who becomes the first airplane fatality. *the painter flynn

the painter flynn



1914  In 1898, with the aid of his friend, Charles Walcott, Director of the U.S. Geological Survey, Samuel Pierpont Langley became the third Secretary of the Smithsonian Institution , secured funding, including $50,000 from the U.S. War Department, to build a full-scale, piloted flying machine that he named, Aerodrome A. 

 Langley had his first genuine success on May 6, 1896, with his Aerodrome Number 5. It made the world's first successful flight of an unpiloted, engine-driven, heavier-than-air craft of substantial size. It was launched from a spring-actuated catapult mounted on top of a houseboat on the Potomac River near Quantico, Virginia.
On October 3, 1903, the first flight attempt of Aerodrome A splashed into the Potomac River with Langley’s assistant, Charles Manly, at the controls. A second attempt on December 9 proved equally disastrous with the aircraft breaking apart soon after launch and crashing into the water. Though the pilot was unharmed, public ridicule in the press forever damaged Langley’s aviation dreams. He died three years later without making another flight.
In 1917, Walcott tried Langley's Aerodrome 5 using pontoons made by Glenn Curtiss.   . On September 17, 1914, the Great Aerodrome made a successful flight over Lake Keuka in New York. Secretary Walcott now felt that he had evidence to resurrect Langley’s rightful place in aviation history.

*Washington Post



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 30th Mersenne Prime and largest known prime (to that date), 2216091− 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





BIRTHS


1794 Marie Jean Antoine Nicolas de Caritat, Marquis of Condorcet (French: [; 17 September 1743 – 29 March 1794), known as Nicolas de Condorcet, was a French philosopher and mathematician. His ideas, including support for a liberal economy, free and equal public instruction, constitutional government, and equal rights for women and people of all races, have been said to embody the ideals of the Age of Enlightenment, of which he has been called the "last witness", and Enlightenment rationalism. A critic of the constitution proposed by Marie-Jean Hérault de Séchelles in 1793, the Convention Nationale — and the Jacobin faction in particular — voted to have Condorcet arrested. He died in prison after a period of hiding from the French Revolutionary authorities. 

From 1765 to 1774, he focused on science. In 1765, he published his first work on mathematics, entitled Essai sur le calcul intégral, which was well received, launching his career as a mathematician. He went on to publish more papers, and on 25 February 1769, he was elected to the Académie royale des Sciences.

Condorcet worked with Leonhard Euler and Benjamin Franklin. He soon became an honorary member of many foreign academies and philosophic societies, including the American Philosophical Society (1775), the Royal Swedish Academy of Sciences (1785), the American Academy of Arts and Sciences (1792) and also in Prussia and Russia.

In 1785, Condorcet published his Essay on the Application of Analysis to the Probability of Majority Decisions, one of his most important works. This work described several now famous results, including Condorcet's jury theorem, which states that if each member of a voting group is more likely than not to make a correct decision, the probability that the highest vote of the group is the correct decision increases as the number of members of the group increases, and Condorcet's paradox, which shows that majority preferences can become intransitive with three or more options – it is possible for a certain electorate to express a preference for A over B, a preference for B over C, and a preference for C over A, all from the same set of ballots.

The paper also outlines a generic Condorcet method, designed to simulate pair-wise elections between all candidates in an election. He disagreed strongly with the alternative method of aggregating preferences put forth by Jean-Charles de Borda (based on summed rankings of alternatives). Condorcet was one of the first to systematically apply mathematics in the social sciences.

He also considered the instant-runoff voting elimination method, as early as 1788, though only to condemn it, for its ability to eliminate a candidate preferred by a majority of voters.

Condorcet's statue by Jacques Perrin, on Quai de Conti in Paris, France





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. Even better, he suggested that the variability was caused by a dark object, possibly a planet, that regularly passed in front of the star. The modern explanation is that Algol is a binary star, with the eclipse caused by the smaller orbiting star.

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 recognize this honor, because he died four days later, in York, from pneumonia.*TIS

The constellation Perseus, engraving, in Johann Bayer, Uranometria, 1603. Algo (beta Persei) is the star in the right eye of the head of Medusa (Linda Hall Library)





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 



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





DEATHS

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

Vega published a series of books containing logarithmic tables. The first volume appeared in 1783. Much later, in 1797, it was followed by a second volume that included a collection of integrals and other useful formulae. His Handbook, originally published in 1793, was later translated into several languages and issued in over 100 editions.

His most significant work was Thesaurus Logarithmorum Completus (Treasury of All Logarithms), first published in 1794 in Leipzig (its 90th edition appeared in 1924). Although based on the tables of Adriaan Vlacq, Vega's version corrected numerous errors and extended the logarithms of trigonometric functions for small angles. An engineer, Franc Allmer, an honorary senator of the Graz University of Technology, discovered a copy of Vega's 10-digit logarithmic tables in the Museum of Carl Friedrich Gauss in Göttingen. Gauss frequently used Vega's tables and even wrote calculations in the margins. He also found and marked some errors in the millions of values Vega had calculated.

A copy of Thesaurus Logarithmorum Completus from the private collection of mathematician and computing pioneer Charles Babbage (1791–1871) is preserved at the Royal Observatory, Edinburgh.

Over the years, Vega also wrote a four-volume textbook titled Vorlesungen über die Mathematik (Lectures on Mathematics). Volume I was published in 1782 when Vega was 28 years old, followed by Volume II in 1784, Volume III in 1788, and Volume IV in 1800. These textbooks include valuable tables; for example, Volume II contains closed-form expressions for the sines of multiples of 3 degrees, presented in a user-friendly format.

Vega also authored at least six scientific papers. On August 20, 1789, he set a world record by calculating pi to 140 decimal places, of which the first 126 were correct. *Wik




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



1876 Charles Davies (January 22, 1798 – September 17, 1876) was a professor of mathematics at the United States Military Academy, notable for writing a series of mathematical textbooks.

Davies was born in Washington, Connecticut. His father was a County Sheriff or County Judge. During Davies' early years, the family moved to St Lawrence County, New York, where he was educated in local schools. He entered the US Military Academy at West Point in December 1813, through the influence of General Joseph Swift, who had met Davies' father during the War of 1812. Davies had earned praise for the services rendered to General James Wilkinson's army in the Descent of the St. Lawerence during the fall of 1813. Having been brought up on the frontier, Davies had had little formal education, but he had no difficulty in pursuing the courses at the academy. He graduated from the academy in December 1815.

He joined the Light Artillery as a Bvt. Second Lieut. on December 11, 1815. He served a year in garrison at New England posts till August 31, 1816, when he was transferred to the Corps of Engineers. He resigned from the Army on December 1, 1816, and took a post as Assistant Professor of Mathematics at West Point. He became a Professor in May 1823.

Davies resigned from West Point in May 1837. From 1839 till 1841, he was a professor at Trinity College in Hartford, Connecticut, wherein he established a connection with Alfred Smith Barnes for publication of his books. He resigned from this position due to illness. He was reappointed in the army as a paymaster in November 1841, and was the Treasurer at West Point from December 11, 1841, to December 19, 1846. In 1848, he joined the New York University as a Professor of Mathematics and Natural Philosophy. Upon his retirement a year later, he was conferred the degree of Doctor of Law from Geneva College, New York. Davies had chosen to retire to devote more time in writing textbooks. After a brief teaching stint at the Normal School in Albany, New York, he accepted a position at Columbia College, New York City in 1857 and was appointed as emeritus professor in 1865.

He died on September 17, 1878. He was engaged with authoring textbooks till his death. He was buried in the family cemetery at Oswegatchie, New York.

Charles Davies' books were published by A.S. Barnes & Co. His earliest works were translations of French authors. But according to author John H. Lienhard, those books were based only very loosely upon the original French works. Elements of Geometry and Trigonometry (1828), his most popular work, appeared in 33 editions/printings and sold more than 300,000 copies. By 1875, his publisher had sold over 7,000,000 copies of his books and was selling 350,000 copies every year.

Mathematical historian Florian Cajori wrote of his books as being "perspicuous, clear, and logically arranged."

The following works by Davies were used as textbooks at West Point:

Elements of Descriptive Geometry, with Their Application to Spherical Trigonometry, Spherical Projections, and Warped Surfaces (1826); 1866 edition

Elements of Geometry and Trigonometry (1828), translated from the French of A. M. Legendre, by David Brewster. Revised and Adapted to the Course of Instruction in the United States.

Elements of Surveying (1830)

A Treatise on Shades and Shadows, and Linear Perspective (1832)

Common School Arithmetic (1833)

Elements of Algebra (1835), translated from the French Élémens d'algèbre of M. Pierre Louis Marie Bourdon [fr][6]

Elements of the Differential and Integral Calculus (1836)

Elements of Analytical Geometry (1837); 1845 revised edition

I own a copy of his Practical Arithmetic, 1876  *Wik *PB notes




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

About 40 "substantially complete" copies of the original 1844-1846 edition still exist and at least two facsimile editions have been issued.

William Henry Fox Talbot’s home, Lacock Abbey in Wiltshire, England, was used as a filming location for several of the Harry Potter movies. Parts of the abbey’s cloisters, chapter house, and sacristy were used to represent areas of Hogwarts School of Witchcraft and Wizardry in The Philosopher’s/Sorcerer’s Stone and The Chamber of Secrets, among others.

“The Open Door” plate six from The Pencil of Nature. This print is a variant of the print presented in the book. It was removed from it’s backing and remains in better condition than many others. Image



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.)


For more information about Lt. Selfridge and his early relation to flying, the Fort Myers, and Alexander G. Bell, see this great article at the Smithsonian site sent to me by the author, Julia Blakely.


1994 Sir Karl Raimund Popper CH FRS FBA (28 July 1902 – 17 September 1994) was an Austrian–British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the classical inductivist views on the scientific method in favour of empirical falsification, and for founding the Department of Philosophy at the London School of Economics. According to Popper, a theory in the empirical sciences can never be proven, but it can be falsified, meaning that it can (and should) be scrutinized with decisive experiments. Popper was opposed to the classical justificationist account of knowledge, which he replaced with "the first non-justificational philosophy of criticism in the history of philosophy", namely critical rationalism.

In political discourse, he is known for his vigorous defense of liberal democracy and the principles of social criticism that he believed made a flourishing open society possible. His political thought resides within the camp of Enlightenment rationalism and humanism. He was a dogged opponent of totalitarianism, nationalism, fascism, romanticism, collectivism, and other kinds of (in Popper's view) reactionary and irrational ideas, and identified modern liberal democracies as the best-to-date embodiment of an open society.

In 1937, Popper finally managed to get a position that allowed him to emigrate to New Zealand, where he became lecturer in philosophy at Canterbury University College of the University of New Zealand in Christchurch. It was here that he wrote his influential work The Open Society and Its Enemies. In Dunedin he met the Professor of Physiology John Carew Eccles and formed a lifelong friendship with him. In 1946, after the Second World War, he moved to the United Kingdom to become a reader in logic and scientific method at the London School of Economics (LSE), a constituent School of the University of London, where, three years later, in 1949, he was appointed professor of logic and scientific method. Popper was president of the Aristotelian Society from 1958 to 1959. He resided in Penn, Buckinghamshire.

Popper died of "complications of cancer, pneumonia and kidney failure" in Kenley at the age of 92 on 17 September 1994. He had been working continuously on his philosophy until two weeks before when he suddenly fell terminally ill, writing his last letter two weeks before his death as well.




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

Carlitz was sometimes called the “one-man mathematical journal” because of his astonishing output (over 770 papers!).

Carlitz had a reputation for replying almost instantly to mathematical queries. Colleagues joked that if you sent him a letter in the morning describing a new problem in combinatorics or number theory, by evening you’d already receive a reply with a general theorem—and possibly the draft of a paper—worked out.

The mathematician George Andrews once remarked that Carlitz seemed to publish faster than anyone could possibly read, let alone referee, his work. Editors would sometimes receive submissions from him so frequently that they half-seriously wondered whether he had a secret team of assistants—when in fact it was just Carlitz’s unmatched speed and energy.

This relentless pace also had a funny side: one young mathematician recalled nervously showing Carlitz a new identity he had discovered. Carlitz listened politely, then replied, “Yes, very nice—I proved it in 1942.” And then, with a smile, added, “but your proof is prettier.” 

One student joked that “working with Carlitz was like trying to take a sip from a fire hydrant.” Another said that the real challenge of being his student wasn’t solving problems but keeping up with the ones he solved for you before you even knew you had them. PBnotes





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


A Curious Property of Vulgar Fractions

     

Another from 2008, hope you enjoy:


John Farey was a geologist, not a mathematician, but he is better remembered today for a single short (four paragraphs) paper he wrote in 1816 than for all his good works in geology. In that year he sent a paper to the Philosophical Magazine (or at least it was published in that year) called On a curious property of vulgar fractions and described a pattern that appears in sequences of what we would today call common (vulgar is the Latin term for common) fractions, like 3/8 etc, which are in simplest terms. The observation has almost NO practical use, not even to prove other things mathematically, and yet, it seems to have all kinds of interesting properties that tend to keep us fascinated with it. If you have never been introduced to it, here is a brief description, and some novel relationships that I think are interesting, with some links to places where they are made clearer than I could do in this brief space.

So First... What is it we are talking about? If you take ALL the fractions that could be written in simplest terms with a denominator less than some number n, say n=5 (since that is the one Farey used in his paper), and put them in order from lowest to highest... you get
The "curious" thing that Farey noticed is that if you ignore the way your fifth grade teacher taught you to add fractions, and do it the way YOU would have added them, "add the tops, add the bottoms", then each number in the sequence is the sum of the terms on each side of it... for example 1/4 and 2/5 are on each side of 1/3, and if you add by this approach you get (1+2)/(4+5) = 3/9 and that simplifies to 1/3 . The number obtained by adding two fractions in this fashion is often called the mediant .

OK, so that is how you make them. Our first question might be, how many of them are there? F(5) obviously has eleven terms (I counted). If we picked a value of N, what would be the number of fractions in the set F(N). A little investigation would show that F(1) = 2 (0 and 1); and F(2) = 3 (0, 1/2, and 1). So how many would be added to the next set... and the next... it turns out that each new set will have all the values of the previous set (of course) and will add one for every value of one through n that is co-prime (has no common divisors) to n. So the set for N=6 will have the eleven terms of F(5) plus 1/6 (one has no common factor with six), and 5/6. (notice that 2/6, 3/6, and 4/6 are already in the sequence in F(5) in simplified form)... thus F(6) has thirteen terms.. and in general we get a recursive formula that say the Order of F(N) = Order of F(n-1) + φ(n). Euler's \(\phi\) function,(sometimes called the totient, like quotient) he number of integers k in the range 1 ≤ k ≤ n for which the greatest common divisor gcd(n, k) is equal to 1.( and no, Euler never used either term.)
 
A second nice curiosity related to Farey Sequences are the Ford Circles. "Ford circles are named after American mathsedematician s the R. Ford, Sr., who described them in an article in American Mathematical Monthly in 1938, volume 45, number 9, pages 586-601" (from Wikipedia). In fact, the wikipedia article is a nice place to see how they work, and I need say no more as it shows the circles for F(5). What is amazing is that each circle is tangent to every other circle for a fraction it will be adjacent to in ANY sequence.... ahhh, go on..say "cool".

I decided to mention this when I came across another curious property of Farey sequences that relates them to lines on the plane and Pick's Theorem. If you treated each fraction a/b as a point (b,a) then none of the lines cross. If you make a triangle with the origin and any two adjacent Farey fractions, since each of the triangles have a determinant of one (meaning the area is 1/2) and therefore, by PIck's theorem, they cannot contain any other lattice points in their interior. A nice explanation of this, including the photo below, was at the Cut-The-Knot web site

Tuesday, 15 September 2026

On This Day in Math - September 16

  




...[T]o many it is not knowledge but the quest for knowledge that gives greater interest to thought—to travel hopefully is better than to arrive

~Sir James Jeans


The 259th day of the year;259 expressed in base six is a repunit, 1111 (63+62+ 61+60= 216+36+6+1=259)

Probably 259 is the largest number that can be written in two ways as \(2^x + 3y\). Here \(259 = 2^8 + 3^1 = 2^4 + 3^5\).

259 can be expressed as the sum of four cubes in two different ways, 259 = 13 + 23 + 53 + 53= 23 + 23 + 33 + 63

and for my ex-students from Japan, 259  is The number of Pokémon originally available in Pokémon Gold and Silver



EVENTS

1566 Tycho Brahe departs Wittenberg to avoid the plague. Early In 1566 he left Denmark and arrived at Wittenberg on the 15th of April. The University of Wittenberg had been founded in 1502, and had then for nearly fifty years been one of the most renowned in Europe. He Studied under Caspar Peucer, distinguished as a mathematician, a physician, and a historian. Tycho, however, did not profit very much from Peucer's instruction, as the plague broke out at Wittenberg, so that he was induced to leave it on the 16th September, after a stay of only five months. *TYCHO BRAHE, A PICTURE OF SCIENTIFIC LIFE AND WORK IN THE SIXTEENTH CENTURY BY J. L. E. DREYER



1636 In a letter to Roberval, Fermat writes, If a and b are rational, and if \( a^2+b^2 = 2(a+b)x= x^2 \), then x and x2 are irrational. *Lemmemeyer, EULER, GOLDBACH, AND “FERMAT’S THEOREM”



In 1662, the first recorded astronomical observation by the (to become) first Astronomer Royal was John Flamsteed's observation of a solar eclipse from his home in Derby at the age of sixteen, about which he corresponded with other astronomers. Flamsteed's interest in astronomy was stirred by the solar eclipse, and besides reading all he could find on the subject he attempted to make his own measuring instruments. *TIS



1693 In a letter to John Locke, Newton apologized for ill thoughts that he had harbored against Locke. *VFR Locke was strongly denounced by several writers and even called an atheist, notably by John Edwards, but such charges were commonplace against every departure from Orthodoxy. During his period of insanity (following 1693) Isaac Newton made similar charges against Locke; at least he wrote Locke a strange letter apologizing for considering him a Hobbist and having charged him with attacking the root of morality,*Contra Mundum, No. 1 Fall 1991, "At the Origins of English Rationalism", by T.E. Wilder (Locke and Newton were usually friends)


1787 Jefferson writes his ex law professor, George Wythe in regard to the construction of geometric models in the classroom.  Wythe is considered one of the finest jurists of the period, and had Jefferson, Monroe, and John Marshall as students.

"I have reflected on your idea of wooden or ivory diagrams for the geometrical demonstrations. I should think wood as good as ivory; & that in this case it might add to the improvement of the young gentlemen; that they should make the figures themselves. Being furnished by a workman with a piece of veneer, no other tool than a penknife & a wooden rule would be necessary. Perhaps pasteboards, or common cards might be still more convenient. The difficulty is, how to reconcile figures which must have a very sensible breadth, to our ideas of a mathematical line, which, having neither breadth nor thickness, will revolt more at these than at simple lines drawn on paper or slate. If after reflecting on this proposition you would prefer having them made here, lay your commands on me and they shall be executed."

This is a full 100 years before Kline brought his models to America and influenced their use in American education.  The earliest record of model building dates back to 1873 and deals with a plaster model of Steiner's Roman surface built by German mathematician Ernst Kummer.  The Roman surface, also called the Steiner surface (not to be confused with the class of Steiner surfaces of which the Roman surface is a particular case), is a quartic nonorientable surface.  The Roman surface is one of the three possible surfaces obtained by sewing a Möbius strip to the edge of a disk.  


*Wik



1804 J L Gay-Lussac sets height record of 22,000+ feet during balloon lift to make measurements of magnetism and electricity.  Earlier on August 24, 1804, Joseph Louis Gay-Lussac and Jean-Baptiste Biot ascended in a hot air balloon to a height of 4,000 meters altitude in order to conduct scientific experiments on gases. These experiments measuring the expansion of gasses led to him publishing the law he dubbed Charles Law, perhaps giving JAC Charles more credit than was due.

Jacques Alexandre César Charles had discover this law around 1787, based on experiments with air and hydrogen gas; however, Charles never published his findings himself. 

Gay-Lussac formally stated the law, but acknowledged that the unpublished experiments were originally conducted by Charles. It is  sometimes called Gay-Lussac’s Law in older French texts—but he himself deferred the credit to Charles. Over time, the name "Charles’s Law" became standard.*PBnotes

*Science History Inst

1810 Rise Up and Revolt!!!   (And they did.)

The Cry of Dolores[n 1] (Spanish: Grito de Dolores) occurred in Dolores, Mexico, on 16 September 1810, when Roman Catholic priest Miguel Hidalgo y Costilla rang his church bell and gave the call to arms that triggered the Mexican War of Independence. The Cry of Dolores is most commonly known by the locals as El Grito de Independencia (The Independence Cry).

Every year on the eve of Independence Day, the president of Mexico re-enacts the cry from the balcony of the National Palace in Mexico City while ringing the same bell Hidalgo used in 1810. During the patriotic speech, the president calls out the names of the fallen heroes who died during the War of Independence and ends the speech by shouting "¡Viva México!" three times, followed by the Mexican National Anthem.

In the 1810s, what would become Mexico was still New Spain, part of the Spanish crown. Following Napoleon's overthrow of the Spanish branch of the Bourbon monarchy in 1808, Spain's American possessions rose in rebellion, refusing to accept Napoleon's brother, Joseph Bonaparte, as king. In New Spain, the criollo leadership attempted to set a course of autonomy in support of the legitimate heir to the throne, Ferdinand VII, but the peninsular elite, fearing the loss of the colony, carried out a coup, also in the name of Ferdinand. Almost immediately, groups of creoles formed various plots around the viceroyalty, including in Querétaro, of which Father Hidalgo became a part.

When the plot was discovered in early September 1810, some plotters decided to proceed with the uprising.[1] Around 2:30 am on 16 September 1810, Hidalgo ordered the church bells to be rung and gathered his congregation. Flanked by Ignacio Allende and Juan Aldama, he addressed the people in front of his church, urging them to revolt. His speech became known as the "Cry of Dolores".[2]

The liberated country adopted Mexico as its official name. Mexico's independence from Spain took a decade of war. Independence was achieved by the Declaration of Independence of the Mexican Empire 11 years and 12 days later, on 28 September 1821. However, Hidalgo is credited as being the "father of his country"*Wik

Father Miguel Hidalgo y Costilla with the movement's banner; statue in Atotonilco



In 1835, British naturalist Charles Darwin, aboard the ship HMS Beagle, arrived at the Galapagos archipelago, a cluster of islands on the equator 600 miles west of South America. During his five weeks studying the fauna in the Galapagos, Darwin found the giant tortoises there greatly differed from one another according to which island they came from. Moreover, many islands developed their own races of iguanas. These observations contributed to his theory of “natural selection,” that species evolved over thousands of millions of years. *TIS 



1848 Weierstrass came to the Catholic Gymnasium in Braunsberg, his third such position. That year he taught mathematics 19 hours per week, took over the geography class after Easter, and received a special note of thanks for helping out in gym! [From the annual report of the Gymnasium in the University of Louisville’s Bullitt Collection of Mathematics. *VFR



1895 Pearson writes to Yule, "I had a most kindly and encouraging letter from Francis Galton about my Heredity paper. He really is a fine old fellow to take my modification of his views so well." *The History of Statistics: The Measurement of Uncertainty Before 1900
By Stephen M. Stigler



1986 “Four out of three jocks can’t count,” read a headline in The Harvard Lampoon’s parody of USA Today. *VFR




BIRTHS


1494 Francisco Maurolico(September 16, 1494-July 21 or July 22, 1575) was an Italian Benedictine who wrote important books on Greek mathematics. He also worked on geometry, the theory of numbers, optics, conics and mechanics.*SAU (His Arithmeticorum libri duo (1575) includes the first known proof by mathematical induction. (First in western mathematics; The 10th Century Persian mathematician Muhammad Al-Karaji was one of the first to use the method of proof by mathematical induction to prove his results, by proving that the first statement in an infinite sequence of statements is true, and then proving that, if any one statement in the sequence is true, then so is the next one. Among other things, Al-Karaji used mathematical induction to prove the binomial theorem.) He proved that the sum of the first n odd numbers is equal to n2 .) Maurolico's astronomical observations include a sighting of the supernova that appeared in Cassiopeia in 1572. Tycho Brahe published details of his observations in 1574; the supernova is now known as Tycho's Supernova.*Wik



1736 Johannes Nikolaus Tetens (16 Sep 1736; 17 Aug 1807) German natural philosopher whose empirical approach strongly influenced the work of Immanuel Kant, and later in his life, Tetens became interested in mathematics, especially in actuarial applications. From 1760, as a teacher of natural philosophy he wrote on diverse topics but later began the development of the field of developmental psychology in Germany. He wrote Philosophische Versuche über die menschliche Natur und ihre Entwickelung (1777) on the origin and structure of knowledge. He changed career after 1789 to the civil service during which time he pursued mathematics. As a statistician he produced an Introduction to the Calculation of Life Annuities (1785) and On the Tetens Mortality Curve (1785)*TIS



1804 Squire Whipple (16 Sep 1804; 15 Mar 1888) U.S. civil engineer, inventor, and theoretician who provided the first scientifically based rules for bridge construction, was considered one of the top engineers of the 19th Century, and was known as the "father of iron bridges." He began his career as a bridge-builder in 1840 by designing and patenting an iron-bridge truss. During the next ten years he built several bridges on the Erie canal and the New York and Erie railroad. His design of the Whipple truss bridge was the model for hundreds of bridges that crossed the Erie Canal in the late 19-th century. Before developing his design, Whipple worked for several years on surveys, estimates, and reports for the enlargement of the Erie Canal, and in 1840 he patented a scale for weighing canal boats. He later built the first weighing lock scale constructed on the Erie Canal. The invention of the steam engine required bridges which could support heavy live loads and this motivated Squire to turn his attention to bridges. In 1853, he completed a 146-ft span iron railroad bridge near West Troy (now Watervliet), N.Y. His book on the design of bridges using scientific methods (1847) was the first of its kind. The formulas and his methods are still useful. He obtained a patent for his lift draw-bridge in 1872.*TIS

Completed after Whipple's death, the Cairo Rail Bridge was built in two 518 feet (157.9 m) Whipple truss spans, each the largest of that design ever constructed.  In order to comply with regulations meant to allow steam boat travel on the Ohio, the bridge was required to be 53 feet (16 m) above the river's high-water mark. This resulted in the structure extending nearly 250 feet (76 m) from the bottom of the deepest foundation to the top of the highest iron work. The bridge, substructure and superstructure weighed 194.6 million pounds (88,270 t), excluding the approaches.

In 1952, that original superstructure was replaced. A new bridge, completed in 1952, reused many of the original piers but has different spans (Warren-type truss spans etc.).  *PBnotes




1929 Murray Gell-Mann (September 15/16, 1929 – May 24, 2019) was an American theoretical physicist who played a preeminent role in the development of the theory of elementary particles. Gell-Mann introduced the concept of quarks as the fundamental building blocks of the strongly interacting particles, and the renormalization group as a foundational element of quantum field theory and statistical mechanics. He played key roles in developing the concept of chirality in the theory of the weak interactions and spontaneous chiral symmetry breaking in the strong interactions, which controls the physics of the light mesons. In the 1970s he was a co-inventor of quantum chromodynamics (QCD) which explains the confinement of quarks in mesons and baryons and forms a large part of the Standard Model of elementary particles and forces.

Murray Gell-Mann received the 1969 Nobel Prize in Physics for his work on the theory of elementary particles.*Wik



1931 Ennackal Chandy George Sudarshan (16 September 1931 – 13 May 2018)  is a prominent Indian-American physicist, author and professor at the University of Texas at Austin. Sudarshan has made significant contributions to several areas of physics. He was the originator (with Robert Marshak) of the V-A theory of the weak force (also done later by Richard Feynman and Murray Gell-Mann), which eventually paved the way for the electroweak theory. Feynman said in 1963: "The V-A theory that was discovered by Sudarshan and Marshak, publicized by Feynman and Gell-Mann".

He also developed a quantum representation of coherent light (for which Glauber was awarded the 2005 Nobel). *Wik



1963 Bernard Kippelen (1963, - )serves as Vice Provost for International Initiatives and holds the Steven A. Denning Chair for Global Engagement at the Georgia Institute of Technology. He is also the Joseph M. Pettit professor in Electrical and Computer Engineering.

Kippelen joined Georgia Tech in 2003 as a member of the faculty with the rank of professor. From 2011-2019 he served as Director of the Center for Organic Photonics and Electronics on the Georgia Tech campus in Atlanta. He is a co-founder and co-President of the Institut Lafayette, an innovation platform located on Georgia Tech’s European site Georgia Tech Europe (Metz, France).

As Vice Provost for International Initiatives at Georgia Tech (since 2021), he oversees the international strategy, global campuses, actively participates in philanthropic engagement, corporate development, and partnerships that connect research and education worldwide. This role has provided him with extensive experience in fiscal management ).

He was born in Guebwiller, raised in Soultz, Alsace, France, and is a US and French citizen. He studied at the University Louis Pasteur in Strasbourg (aka University of Strasbourg) where he received a Maitrise in Solid-State Physics in 1985, and a Doctorate in Nonlinear Optics in 1990. From 1990 to 1997 he was Chargé de Recherches at the French CNRS. In 1991, he joined the Optical Sciences Center at the University of Arizona as a postdoctoral fellow, held several research faculty positions, and joined the faculty in 1998 as a tenure-track Assistant Professor. He was promoted to Associate Professor with tenure in 2001.

His most impactful research contributions are in the field of organic optoelectronics, including the development of organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), organic photovoltaics, and organic photodiodes. He holds 26 issued patents and has co-authored over 700 scientific communications, including over 300 peer-reviewed journal publications and 14 book chapters. His work has received over 34,000 citations and his h-index is currently 94 (Google Scholar). He served as chair and co-chair of numerous international conferences on organic optoelectronic materials and devices. He has graduated 30 Ph.D. students and advised 23 postdoctoral fellows. He taught passionately many courses both at the undergraduate and graduate levels, both in the classroom and online. He contributed to curriculum development at the frontiers of optics, physics, engineering, materials science, and chemistry. The numerous teaching awards and accolades he received from his past students are a source of pride.

Kippelen is the recipient of an NSF-Career Award (2000), a 3M Corporation Young Faculty Award (2000), a FlexTech Alliance Award (2012), a Printed Electronics USA Award (2012), the Georgia Tech Class of 1934 Outstanding Interdisciplinary Activity Award (2014), and the Georgia Tech Steven A. Denning Faculty Award for Global Engagement (2019). His research was featured in numerous media outlets, including Forbes and Reuters. He was elected a Fellow of Optica (formerly known as the Optical Society of America) (2006), a Fellow of SPIE (2007), and bestowed the title of Knight of the French National Order of Merit (2023). He served as a Deputy Editor for Optics Express (2009-2012) and was the founding Editor of Energy Express (2010-2012).   

Education

Doctorate in Nonlinear Optics, University Louis Pasteur Strasbourg (now University of Strasbourg), 1990

Maitrise in Solid‑State Physics, University Louis Pasteur Strasbourg, 1985

Research Interests

Organic light-emitting devices for displays and lighting

Flexible organic photovoltaic cells for power generation

Organic photodetectors and sensors

Printed electronics

Structure-property relationships in photonic and electronic materials

Teaching Interests

Kippelen's teaching interests include electromagnetics, optoelectronics, and organic optoelectronics, and he has contributed to curriculum development at the frontiers of optics, physics, engineering, materials science, and chemistry.

Distinctions & Awards

Knight of the French National Order of Merit

NSF CAREER Award

3M Young Faculty Award

Senior Member, IEEE

Fellow, the Optical Society of America

Fellow, the International Society for Optical Engineering  *Ga Tech College of Engineering

And from my brief personal experience, a really nice guy.  *PB

Bernard has always had a passion for mountains and climbed Mount Blanc in the French Alps with his wife, Virginie.

***Mont Blanc is the highest mountain in the Alps and Western Europe, rising about 4,809 meters (15,777 feet) above sea level on the border between France and Italy.  (Layman's translation:"  It's high, snowy, dangerous and very cold.... )







DEATHS


1736 Gabriel Daniel Fahrenheit (24 May 1686, 16 Sep 1736) was a German-Dutch physicist and instrument maker (meteorological). He lived in Holland for most of his life. He invented the alcohol thermometer (1709) and mercury thermometer (1714) and developed the Fahrenheit temperature scale. For the zero of his scale he used the temperature of an equal ice-salt mixture; 30° for the freezing point of water; and 90° for normal body temperature. Later, he adjusted to 32° for the freezing point of water and 212° for the boiling point of water, the interval between the two being divided into 180 parts. He also invented a hygrometer to measure relative humidity and experimented with other liquids discovering that each liquid had a different boiling point that would change with atmospheric pressure.*TIS



1925 Alexander Alexandrovich Friedmann (16 Jun 1888, 16 Sep 1925) Russian mathematician who was the first to work out a mathematical analysis of an expanding universe consistent with general relativity, yet without Einstein's cosmological constant. In 1922, he developed solutions to the field equations, one of which clearly described a universe that began from a point singularity, and expanded thereafter. In his article On the Curvature of Space received by the journal Zeitschrift für Physik on 29 Jun 1922, he showed that the radius of curvature of the universe can be either an increasing or a periodic function of time. In Jul 1925, he made a record-breaking 7400-m balloon ascent to make meteorological and medical observations. A few weeks later he fell ill and died of typhus. *TIS



1931 Niels Nielsen (2 Dec 1865 , 16 Sept 1931) was a Danish mathematician who worked on special functions and number theory. *SAU

In 1917 he suffered from an illness from which he never fully recovered. From this date onward he became interested in the number theory, Bernoulli numbers, Stirling numbers, and the history of mathematics, writing two books on Danish mathematicians of the time period 1528-1908, and two other books on French mathematicians. *Wik



1932 Sir Ronald Ross (born 13 May 1857, 16 Sep 1932) English physician, bacteriologist and mathematician whose discovery of the malarial parasite in the gastrointestinal tract of the Anopheles mosquito led to the realization that malaria was transmitted by Anopheles. For this work, he was awarded the 1902 Nobel Prize for Physiology or Medicine, becoming the first British Nobelist. He began studying malaria in 1892. In 1894 he made an experimental investigation in India of the hypothesis of Alphonse Laveran and Patrick Manson that mosquitoes are connected with the propagation of the disease. After two and a half years' failure, Ross succeeded in demonstrating the life-cycle of the parasites of malaria in mosquitoes, thus establishing the hypothesis of Laveran and Manson. Later, in West Africa he found the species of mosquitoes which convey the deadly African fever.*TIS (He is most remembered for his work on malaria, but his greatest influence may have come from his development and publishing of a mathematical theory of epidemiology.)



1946 Sir James Hopwood Jeans (11 Sep 1877, 16 Sep 1946) was an English physicist, astronomer, and mathematician who was the first to propose that matter is continuously created throughout the universe. He made other innovations in astronomical theory but is perhaps best known as a writer of popular books about astronomy. *TIS

He served as a secretary of the Royal Society from 1919 to 1929, and was the president of the Royal Astronomical Society from 1925 to 1927, and won its Gold Medal

Jeans was elected Fellow of Trinity College in October 1901, and taught at Cambridge, but went to Princeton University in 1904 as a professor of applied mathematics. He returned to Cambridge in 1910.

From 1923 to 1944 he was associated with Caltech's Mount Wilson Observatory.

He made important contributions in many areas of physics, including quantum theory, the theory of radiation and stellar evolution. His analysis of rotating bodies led him to conclude that Pierre-Simon Laplace's theory that the Solar System formed from a single cloud of gas was incorrect, proposing instead that the planets condensed from material drawn out of the Sun by a hypothetical catastrophic near-collision with a passing star. This theory is not accepted today.

Jeans, along with Arthur Eddington, is a founder of British cosmology. In 1928, Jeans was the first to conjecture a steady state cosmology based on a hypothesized continuous creation of matter in the universe.*Wik

...[T]o many it is not knowledge but the quest for knowledge that gives greater interest to thought—to travel hopefully is better than to arrive

~Sir James Jeans



1979 Marion Gray (26 March 1902, 16 Sept 1979) graduated from Edinburgh University and then went to Bryn Mawr College in the USA. She completed her doctorate there and returned to posts at Edinburgh and Imperial College London. She returned to the USA and worked for AT&T for the rest of her career. The Gray graph is named after her.*SAU The Gray graph is an undirected bipartite graph with 54 vertices and 81 edges. It is a cubic graph: every vertex touches exactly three edges. The Gray graph is interesting as the first known example of a cubic graph having the algebraic property of being edge but not vertex transitive *Wik



1989 Allen Shields (May 7, 1927 - September 16, 1989) worked on a wide range of mathematical topics including measure theory, complex functions, functional analysis and operator theory.
An interesting story from George Piranian, of how Shields was appointed to the University of Michigan.

In 1955, on the first day of the American Mathematical Society Summer Meeting in Ann Arbor, George [Piranian] asked Chairman T H Hildebrandt for leave of absence for the Winter Term of 1956. Immediately Hildebrandt declared that he could not grant the request unless George found a replacement. On his way from Hildebrandt's office to one of the lecture sessions, George ran into Allen Shields, whom a year earlier he had met at the Summer Meeting at Laramie. Allen was cooperative, and George dashed back to report that he had found a substitute and that, after fifteen more minutes the substitute would present a ten-minute paper. ... Young as he was, Allen had already mastered the art of beginning his blackboard work in the upper left-hand corner and ending neatly at the lower right, with one minute to spare. Hildebrandt was so impressed that on the spot he offered Allen a one-term appointment. Later, the department persuaded both Shields and Hildebrandt to extend the arrangement.

Soon after George Piranian returned from his leave, he began working with Shields and they published the joint paper The sets of Luzin points of analytic functions (1957). *SAU



2005 Gordon Gould (17 Jul 1920, 16 Sep 2005) American physicist who coined the word "laser" from the initial letters of "Light Amplification by Stimulated Emission of Radiation." Gould was inspired from his youth to be an inventor, wishing to emulate Marconi, Bell, and Edison. He contributed to the WWII Manhattan Project, working on the separation of uranium isotopes. On 9 Nov 1957, during a sleepless Saturday night, he had the inventor's inspiration and began to write down the principles of what he called a laser in his notebook. Although Charles Townes and Arthur Schawlow, also successfully developed the laser, eventually Gould gained his long-denied patent rights. *TIS



2011 Mario Wschebor ( 3 December 1939,   16 September 2011)  was a Uruguayan mathematician and statistician who has a remarkable record of outstanding papers, and an international reputation of speaking at conferences around the world. Yet his career was disrupted by having to flee because of political events. He was also passionate about political and social issues and fought throughout his career for an improved university system. *SAU

In the field of mathematics, he made important contributions to probability and statistics . He was the author of numerous scientific publications, including Level Sets and Extrema of Random Processes and Fields (Wiley, UK, 2009), in collaboration with Jean-Marc Azaïs.

He was a prominent university leader, serving as Dean of the Faculty of Sciences at the University of the Republic from 1987 to 1997, after actively participating in its creation. An important contribution from this period is the Document of the Four Deans , in which he advocated the need for the creation of a national tertiary education system. *Wik



2016   Professor B L Moiseiwitsch BSc PhD MRIA FIoP (died suddenly on 16 September 2016, aged 88)

Obituary supplied by the Moiseiwitsch family

Born in London on 06 December 1927 to Jacob and Chana Moiseiwitsch, Benjamin Lawrence (Benno) was the last surviving of their three children; Daniel (1944) and Victoria (2012).

He had a career interest in theoretical studies in atomic, molecular and optical physics, receiving his PhD in Applied Mathematics from University College London in 1952 before moving almost immediately to Belfast to take up an academic position at Queen’s.

Initially appointed as a lecturer, he was successively promoted to reader, received a personal chair in Applied Mathematics in 1968, was Dean of the Faculty of Science from 1972 to 1975, and became Head of the Department of Applied Mathematics and Theoretical Physics in 1977. He remained in that role until 1989 before retiring in 1993.

During his time at Queen’s he published the first of his three books Variational Principles (1966) and was elected a Member of the Royal Irish Academy (1969).

While he had numerous research collaborations around the world, travelling extensively in North and South America, India and throughout Europe, Professor Moiseiwitsch always returned to Belfast.

After his appointment as Professor Emeritus in Applied Mathematics at Queen’s he continued to be active, publishing his third and most recent book, How to Solve Applied Mathematics Problems, (2011). 

He is survived by his wife of 63 years, Sheelagh, and their four children – Tanya (Coppel), Lisa (Masterman), Julian and Nicholas, by eight grandchildren and four great grandchildren.


*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