Pat'sBlog: December 2019

Sunday, 29 December 2019

On This Day in Math - December 29

Folium of Descartes, *Wiki

Die ganze Zahl schuf der liebe Gott, alles Übrige ist Menschenwerk.
God made the integers, all else is the work of man.

~Leopold Kronecker

The 363rd day of the year; 363 is the sum of nine consecutive primes and is also the sum of 5 consecutive powers of three. It is the last palindrome of the year.

363 is the numerator of the sum of the reciprocals of the first seven integers, $ \frac{1}{1}+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{6}+\frac{1}{7}= \frac{363}{140}$

EVENTS

1566 A part of Tycho Brahe’s nose was cut off in a duel with another Danish nobleman. The dispute was over a point of mathematics. This he replaced with a prosthesis generally stated to be of silver and gold but containing a high copper content. *VFR
On December 10, 1566, Tycho and the Danish blue blood Manderup Parsbjerg were guests at an engagement party at Prof. Bachmeister in Rostock. The party included a ball, but the festive environment did not keep the two men from starting an argument that went on even over the Christmas period. On December 29, they finished the matter with a rapier duel. During the duel, which started at 7 p.m. in total darkness, a large portion of the nose of Brahe was cut off by his Opponent. It was the most famous cut in science, if not the unkindest. *Neatorama

1692 Huygens, in a letter to L’Hospital, gave the ﬁrst complete sketch of the folium of Descartes. Although the curve was ﬁrst discussed 23 August 1638 no complete sketch had previously been given due to a reluctance to use negative numbers as coordinates. *VFR

1763 Nevil Maskelyne 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”.
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.
*Board of Longitude project, Greenwich

1746 Euler writes to praise d'Alembert on his proof of the Fundamental Theorem of Algebra, but disagrees with his idea that log(-x) = log (x).

Euler and d'Alembert's correspondence had begun on August 3, 1746, but several letters between these two, including the one that d'Alembert suggests that log(-x) = log (x) have been lost. *Robert E. Bradley, Ed Sandifer; Leonhard Euler: Life, Work and Legacy

1790 Obituary for Thomas “Tom” Fuller in the Columbian Centinial , Boston Massachusetts. His mathematical ability and its origin became a dueling point between abolitionists and those supporting slavery.

Died- Negro Tom, the famous African Calculator, aged 80 years. He was the property of Mrs. Elizabeth Cox of Alexandria. Tom was a very black man. He was brought to this country at the age of 14, and was sold as a slave.... This man was a prodigy. Though he could never read or write, he had perfectly acquired the art of enumeration.... He could multiply seven into itself, that product by seven, and the products, so produced, by seven, for seven times. He could give the number of months, days, weeks, hours, minutes, and seconds in any period of time that any person chose to mention, allowing in his calculation for all leap years that happened in the time; he would give the number of poles, yards, feet, inches, and barley-corns in any distance, say the diameter of the earth's orbit; and in every calculation he would produce the true answer in less time than ninety-nine men out of a hundred would produce with their pens. And, what was, perhaps, more extraordinary, though interrupted in the progress of his calculation, and engaged in discourse necessary for him to begin again, but he would ... cast up plots of land. He took great notice of the lines of land which he had seen surveyed. He drew just conclusions from facts; surprisingly so, for his opportunities. Had his [Thomas Fuller] opportunity been equal to those of thousands of his fellow-men ... even a NEWTON himself, need have ashamed to acknowledge him a Brother in Science.

*Univ of Buffalo Math Dept

In 1927, Krakatoa began a new volcanic eruption on the seafloor along the same line as the cones of previous activity. By 26 Jan 1928, a growing cone had reached sea level and formed a small island called Anak Krakatoa (Child of Krakatoa). Sporadic activity continued until, by 1973, the island had reached a height of 622 ft above sea level. It was still in eruption in the early 1980s. The volcano Krakatoa is on Pulau (island) Rakata in the Sunda Strait between Java and Sumatra, Indonesia. It had been quiet since its previous catastrophic eruption of 1883. That threw pumice 33 miles high and 36,380 people were killed either by the ash fall or by the resulting tidal wave. The only earlier known eruption was in 1680, and was only moderate.*TIS

1939 Shockley Makes Historic Notebook Entry
William Shockley records in his laboratory notebook that it should be possible to replace vacuum tubes with semiconductors. Eight years later, he, Walter Brattain and John Bardeen at AT&T Bell Laboratories successfully tested the point-contact transistor. Shockley developed much of the theory behind transistor action, and soon postulated the junction transistor, a much more reliable device. It took about ten years after the 1947 discovery before transistors replaced vacuum tubes in computer design as manufacturers learned to make them reliable and a new generation of engineers learned how to use them. *CHM

1947 George Dantzig announced his discovery of the simplex method at the joint annual meeting of the American Statistical Association and the Institute of Mathematical Statistics. The lecture was poorly attended and the result attracted no interest. *Robert Dorfman, “The discovery of linear programming,” Annals of the History of Computing, 6(1984), 283–295, esp. 292.

1979 Edward Lorenz presents a paper at the 139th Annual Meeting of the American Association for the Advancement of Science with the title, "Predictability: Does the flap of a butterfly's wings in Brazil set off a tornado in Texas?" *TIS According to Lorenz, upon failing to provide a title for a talk he was to present at the meeting Philip Merilees concocted the title. The idea that one butterfly could have a far-reaching ripple effect on subsequent events seems first to have appeared in a 1952 short story by Ray Bradbury about time travel. It seems that Merilees was was not familiar with Bradbury’s story. *Wik Found this cartoon @NewYorker

BIRTHS

1256 Birthdate of Ibn Al-Banna who studied the magic properties of numbers and letters. *VFR He was an Islamic mathematician who wrote a large number of works including an introduction to Euclid's Elements, an algebra text and various works on astronomy.*SAU

1796 Johann Christian Poggendorff (29 December 1796 – 24 January 1877), was a German physicist and science historian born in Hamburg. By far the greater and more important part of his work related to electricity and magnetism. Poggendorff is known for his electrostatic motor which is analogous to Wilhelm Holtz's electrostatic machine. In 1841 he described the use of the potentiometer for measurement of electrical potentials without current draw.
Even at this early period he had conceived the idea of founding a physical and chemical scientific journal, and the realization of this plan was hastened by the sudden death of Ludwig Wilhelm Gilbert, the editor of Gilbert's Annalen der Physik, in 1824 Poggendorff immediately put himself in communication with the publisher, Barth of Leipzig. He became editor of Annalen der Physik und Chemie, which was to be a continuation of Gilbert's Annalen on a somewhat extended plan. Poggendorff was admirably qualified for the post, and edited the journal for 52 years, until 1876. In 1826, Poggendorff developed the mirror galvanometer, a device for detecting electric currents.
He had an extraordinary memory, well stored with scientific knowledge, both modern and historical, a cool and impartial judgment, and a strong preference for facts as against theory of the speculative kind. He was thus able to throw himself into the spirit of modern experimental science. He possessed in abundant measure the German virtue of orderliness in the arrangement of knowledge and in the conduct of business. Further he had an engaging geniality of manner and much tact in dealing with men. These qualities soon made Poggendorff's Annalen (abbreviation: Pogg. Ann.) the foremost scientific journal in Europe.
In the course of his fifty-two years editorship of the Annalen Poggendorff could not fail to acquire an unusual acquaintance with the labors of modern men of science. This knowledge, joined to what he had gathered by historical reading of equally unusual extent, he carefully digested and gave to the world in his Biographisch-literarisches Handworterbuch zur Geschichte der exacten Wissenschaften, containing notices of the lives and labors of mathematicians, astronomers, physicists, and chemists, of all peoples and all ages. This work contains an astounding collection of facts invaluable to the scientific biographer and historian. The first two volumes were published in 1863; after his death a third volume appeared in 1898, covering the period 1858-1883, and a fourth in 1904, coming down to the beginning of the 20th century.
His literary and scientific reputation speedily brought him honorable recognition. In 1830 he was made royal professor, in 1838 Hon. Ph.D. and extraordinary professor in the University of Berlin, and in 1839 member of the Berlin Academy of Sciences. In 1845, he was elected a foreign member of the Royal Swedish Academy of Sciences.

Many offers of ordinary professorships were made to him, but he declined them all, devoting himself to his duties as editor of the Annalen, and to the pursuit of his scientific researches. He died at Berlin on 24 January 1877.
The Poggendorff Illusion is an optical illusion that involves the brain's perception of the interaction between diagonal lines and horizontal and vertical edges. It is named after Poggendorff, who discovered it in the drawing of Johann Karl Friedrich Zöllner, in which he showed the Zöllner illusion in 1860. In the picture to the right, a straight black line is obscured by a dark gray rectangle. The black line appears disjointed, although it is in fact straight; the second picture illustrates this fact.*Wik

1856 Birth of Thomas Jan Stieltjes, who did pioneering work on the integral. *VFR Thomas Stieltjes worked on almost all branches of analysis, continued fractions and number theory. *SAU

1861 Kurt Hensel (29 Dec 1861 in Königsberg, Prussia (now Kaliningrad, Russia) - 1 June 1941 in Marburg, Germany) invented the p-adic numbers, an algebraic theory which has proved important in later applications. From 1901 Hensel was editor of the prestigious and influential Crelle's Journal.*SAU

1905 Henri-Gaston Busignies (29 Dec 1905; 20 Jun 1981) French-born American electronics engineer whose invention (1936) of high-frequency direction finders (HF/DF, or "Huff Duff") permitted the U.S. Navy during World War II to detect enemy transmissions and quickly pinpoint the direction from which a radio transmission was coming. Busignies invented the radiocompass (1926) while still a student at Jules Ferry College in Versailles, France. In 1934, he started developing the direction finder based on his earlier radiocompass. Busignies developed the moving target indicator for wartime radar. It scrubbed off the radar screen every echo from stationary objects and left only echoes from moving objects, such as aircraft. *TIS

1911 (Emil) Klaus (Julius) Fuchs (29 Dec 1911; 28 Jan 1988) was a German-born physicist who was convicted as a spy on 1 Mar 1950, for passing nuclear research secrets to Russia. He fled from Nazi Germany to Britain. He was interned on the outbreak of WW II, but Prof. Max Born intervened on his behalf. Fuchs was released in 1942, naturalized in 1942 and joined the British atomic bomb research project. From 1943 he worked on the atom bomb with the Manhattan Project at Los Alamos, U.S. By 1945, he was sending secrets to Russia. In 1946, he became head of theoretical physics at Harwell, UK. He was caught, confessed, tried, imprisoned for nine of a 14 year sentence, released on 23 Jun 1959, and moved to East Germany and resumed nuclear research until 1979. *TIS

1944 Joseph W. Dauben (born 29 December 1944, Santa Monica- ) is a Herbert H. Lehman Distinguished Professor of History at the Graduate Center of the City University of New York. He obtained his Ph.D. from Harvard University.
His fields of expertise are history of science, history of mathematics, the scientific revolution, sociology of science, intellectual history, 17-18th centuries, history of Chinese science, and the history of botany.
His book Abraham Robinson was reviewed positively by Moshé Machover, but he noted that it avoids discussing any of Robinson's negative aspects, and "in this respect [the book] borders on the hagiographic, painting a portrait without warts."
Dauben in a 1980 Guggenheim Fellow and is a Fellow of the American Association for the Advancement of Science, and a Fellow of the New York Academy of Sciences (since 1982).
Dauben is an elected member (1991) of the International Academy of the History of Science and an elected foreign member (2001) of German Academy of Sciences Leopoldina.
He delivered an invited lecture at the 1998 International Congress of Mathematicians in Berlin on Karl Marx's mathematical work. *Wik

DEATHS

1720 Maria Winckelmann (Maria Margarethe Winckelmann Kirch (25 Feb 1670 in Panitzsch, near Leipzig, Germany - 29 Dec 1720 in Berlin, Germany) was a German astronomer who helped her husband with his observations. She was the first woman to discover a comet.*SAU

1731 Brook Taylor (18 Aug 1685, 29 Dec 1731) British mathematician, best known for the Taylor's series, a method for expanding functions into infinite series. In 1708, Taylor produced a solution to the problem of the centre of oscillation. His Methodus incrementorum directa et inversa (1715; “Direct and Indirect Methods of Incrementation”) introduced what is now called the calculus of finite differences. Using this, he was the first to express mathematically the movement of a vibrating string on the basis of mechanical principles. Methodus also contained Taylor's theorem, later recognized (1772) by Lagrange as the basis of differential calculus. A gifted artist, Taylor also wrote on basic principles of perspective (1715) containing the first general treatment of the principle of vanishing points.*TIS

1737 Joseph Saurin (1659 at Courtaison – December 29, 1737 at Paris) was a French mathematician and a converted Protestant minister. He was the first to show how the tangents at the multiple points of curves could be determined by mathematical analysis. He was accused in 1712 by Jean-Baptiste Rousseau of being the actual author of defamatory verses that gossip had attributed to Rousseau.*Wik

1891 Leopold Kronecker (7 Dec 1823, 29 Dec 1891) died of a bronchial illness in Berlin, in his 69th year. Kronecker's primary contributions were in the theory of equations. *VFR
A German mathematician who worked to unify arithmetic, algebra and analysis, with a particular interest in elliptic functions, algebraic equations, theory of numbers, theory of determinants and theory of simple and multiple integrals. However the topics he studied were restricted by the fact that he believed in the reduction of all mathematics to arguments involving only the integers and a finite number of steps. He believed that mathematics should deal only with finite numbers and with a finite number of operations. He was the first to doubt the significance of non-constructive existence proofs, and believed that transcendental numbers did not exist. The Kronecker delta function is named in his honour. *TIS

1941 William James Macdonald (1851 in Huntly, Aberdeenshire, Scotland
Died: 29 Dec 1941 in Edinburgh, Scotland) graduated from the University of St Andrews. He taught at Madras College St Andrews, at Merchiston Castle School and at Donald Stewart's College in Edinburgh. He was a pioneer of the introduction of modern geometry to the mathematical curriculum. He was a founder member of the EMS and became the sixth President in 1887. *SAU

1941 Tullio Levi-Civita (29 Mar 1873, 29 Dec 1941) Italian mathematician who was one of the founders of absolute differential calculus (tensor analysis) which had applications to the theory of relativity. In 1887, he published a famous paper in which he developed the calculus of tensors. In 1900 he published, jointly with Ricci, the theory of tensors Méthodes de calcul differential absolu et leures applications in a form which was used by Einstein 15 years later. Weyl also used Levi-Civita's ideas to produce a unified theory of gravitation and electromagnetism. In addition to the important contributions his work made in the theory of relativity, Levi-Civita produced a series of papers treating elegantly the problem of a static gravitational field. *TIS

1989 Adrien Albert (19 November 1907, Sydney - 29 December 1989, Canberra) was a leading authority in the development of medicinal chemistry in Australia. Albert also authored many important books on chemistry, including one on selective toxicity.
He was awarded BSc with first class honours and the University Medal in 1932 at the University of Sydney. He gained a PhD in 1937 and a DSc in 1947 from the University of London. His appointments included Lecturer at the University of Sydney (1938-1947), advisor to the Medical Directorate of the Australian Army (1942-1947), research at the Wellcome Research Institute in London (1947-1948) and in 1948 the Foundation Chair of Medical Chemistry in the John Curtin School of Medical Research at the Australian National University in Canberra where he established the Department of Medical Chemistry. He was a Fellow of the Australian Academy of Science.
He was the author of Selective Toxicity: The Physico-Chemical Basis of Therapy, first published by Chapman and Hall in 1951.
The Adrien Albert Laboratory of Medicinal Chemistry at the University of Sydney was established in his honour in 1989.[1] His bequest funds the Adrien Albert Lectureship, awarded every two years by the Royal Society of Chemistry *Wik

1989 Hermann (Julius) Oberth (25 Jun 1894, 29 Dec 1989) was a German scientist who was one of three founders of space flight (with Tsiolkovsky and Goddard). After injury in WWI, he drafted a proposal for a long-range, liquid-propellant rocket, which the War Ministry dismissed as fanciful. Even his Ph.D. dissertation on his rocket design was rejected by the University of Heidelberg. When he published it as Die Rakete zu den Planetenräumen (1923; “The Rocket into Interplanetary Space”) he gained recognition for its mathematical analysis of the rocket speed that would allow it to escape Earth's gravitational pull. He received a Romanian patent in 1931 for a liquid-propellant rocket design. His first such rocket was launched 7 May 1931, near Berlin. *TIS

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

Saturday, 28 December 2019

On This Day in Math - December 28

Shadow Family in Cowtown

Anyone who considers arithmetical methods of producing random digits is,

of course,

in the state of sin.

~John Von Neumann

The 362nd day of the year; 362 and its double and triple all use the same number of digits in Roman numerals.*What's Special About This Number.

3!+6!+2! - 1 =727 and 3!*6!*2! + 1=8641 are both prime *Prime Curios

362 is the sum of 3 nonzero squares in exactly 4 ways.(collect the whole set!)

EVENTS
1612 Galileo observed Neptune, but did not recognize it as a planet. Galileo's drawings show that he first observed Neptune on December 28, 1612, and again on January 27, 1613. On both occasions, Galileo mistook Neptune for a fixed star when it appeared very close—in conjunction—to Jupiter in the night sky; hence, he is not credited with Neptune's discovery. (The official discovery is usually cited as September 23, 1846, Neptune was discovered within 1° of where Le Verrier had predicted it to be.) During the period of his first observation in December 1612, Neptune was stationary in the sky because it had just turned retrograde that very day. This apparent backward motion is created when the orbit of the Earth takes it past an outer planet. Since Neptune was only beginning its yearly retrograde cycle, the motion of the planet was far too slight to be detected with Galileo's small telescope.*Wik

1893 Simon Newcomb gives a speech to the New York Mathematical Society with comments on the fourth dimension; "It is a perfectly legitimate exercise .... if we should not stop at three dimensions in geometry, but construct one for space having four... and there is room for an indefinite number of universes". He also called his speculations on the fourth dimension, "the fairlyland of geometry."
The speech appears a short time later on February 1, 1894 in Nature. His comments would also be commented on in H. G. Wells, Time Machine. "But some philosophical people have been asking ... - Why not another direction at right angles to the other three? ... Professor Simon Newcomb was expanding on this only a month or so ago." *Alfred M. Bork, The Fourth Dimenson in Nineteenth-Century Physics, Isis, Sept 1964 pg 326-338

In 1893, Professor James Dewar gave six well-illustrated lectures on "Air gaseous and liquid," at the Royal Institution, London, 28 Dec 1893 - 9 Jan 1894. Some of the air in the room was liquified in the presence of the audience and it remained so for some time, when enclosed in a vacuum jacket. Again, 1 Apr 1898.
My favorite stupid joke about Thermos Bottles: "You put hot stuff in a thermos, it stays hot. You put cold stuff in a thermos, it stays cold. BUT How does the Thermos know which is which?"

1895 Wilhelm Conrad Rontgen announces that he has taken an x-ray of his wife’s hand in a paper, "Ein neue Art von Strahlen", to the Würzburg Physical-Medical-Society on 28 Dec and it appeared in their 1895 proceedings. By January he was famous. In the next year some 50 books and 1000 papers appeared on the subject! A journal devoted to the subject was founded in May 1896.

1895 The Lumières held their first public screening of projected motion pictures in 1895. The Lumière brothers, Auguste Marie Louis Nicolas [oɡyst maʁi lwi nikɔla] (19 October 1862, Besançon, France – 10 April 1954, Lyon) and Louis Jean (5 October 1864, Besançon, France – 6 June 1948, Bandol) were the earliest filmmakers in history. (Appropriately, "lumière" translates as "light" in English.)
Their first public screening of films at which admission was charged was held on December 28, 1895, at Salon Indien du Grand Café in Paris. This history-making presentation featured ten short films, including their first film, Sortie des Usines Lumière à Lyon (Workers Leaving the Lumière Factory). Each film is 17 meters long, which, when hand cranked through a projector, runs approximately 50 seconds. *Wik

1923 George David Birkhoff of Harvard received the ﬁrst Bocher Memorial Prize for his paper “Dynamical systems with two degrees of freedom.” *VFR

1938 Kurt Godel lectures to the annual AMS meeting, Williamsburg, on the consistency of the axiom of choice and the generalized continuum hypothesis. Independence was proved in 1963 by Paul Cohen. *VFR

In 1931, Irene Joliot-Curie reported her study of the unusually penetrating radiation released when beryllium was bombarded by alpha particles seen by the German physicists, Walter Bothe and H. Becker in 1930. Joliot-Curie (daughter of Marie and Pierre Curie) agreed with them that the radiation was energetic gamma rays. She further discovered that if the emitted radiation passed through paraffin (or other hydrogen containing materials), large numbers of protons were released. Since this was, in fact, a previously unknown result for gamma rays, she lacked an explanation. It was to be the experiments of James Chadwick performed during 7-17 Feb that would discover the radiation was in fact new particles - neutrons.*TIS

1973 For a really big ellipse, consider the orbit of the comet Kahoutek, which reached perihelion on this date. The length of the major and minor axes are 3,600 and 44 Astronomical Units. The comet’s eccentricity is approximately 0.99993. *UMAP Journal, 4(1983), p. 164
Comet Kohoutek is a long-period comet; its previous apparition was about 150,000 years ago, and its next apparition will be in about 75,000 years. The comet was discovered on March 18th on photographic plates taken on March 7th and 9th by Czech astronomer Luboš Kohoutek, for whom the comet is named. *Wik

In 2005, the first in a network of satellites, named Galileo, was launched by a consortium of European goverments and companies. By 2011, Galileo will consist of 30 satellites providing worldwide coverage as an alternative to the U.S. monopoly with its Global Positioning System (GPS). At a cost of $4 billion, it's Europe's biggest-ever space project, with one-third contributed by governments and the balance from eight companies. Since the American GPS is controlled by the military, the European satellite network is designed to ensure independance for civilian use, but also offer more precision for a paid service. Customers are expected to include service for small airports, transportation, and mobile phone manufacturers to build in navigation capabilities.*TIS

2009 Longest flight by a paper-only plane-Takuo Toda sets world record
TOKYO, Japan--Using a specially designed 10cm long paper plane, Japanese origami plane virtuoso Takuo Toda's origami flight in a Japan Airlines hangar near Tokyo's Haneda Airport lasted 26.1s - setting the world record for the Longest flight by a paper-only plane.
This one was made strictly in keeping with traditional rules of the ancient Japanese art; only one sheet of paper was folded by hand, with no scissors or glue. He had previously set a record for time aloft with a plane that included tape. *worldrecordsacademy.org
There is a video here.

2013 Voyager 1 is a 722-kilogram (1,590 lb) space probe launched by NASA on September 5, 1977 to study the outer Solar System. Operating for 36 years, 3 months, and 23 days as of 28 December 2013, the spacecraft communicates with the Deep Space Network to receive routine commands and return data. At a distance of about 127.21 AU (1.903×1010 km) from the Earth as of 28 December 2013, it is the farthest humanmade object from Earth. *Wik

BIRTHS
1798 Thomas Henderson (28 Dec 1798; 23 Nov 1844) Scottish astronomer, the first Scottish Astronomer Royal (1834), who was first to measure the parallax of a star (Alpha Centauri, observed at the Cape of Good Hope) in 1831-33, but delayed publication of his results until Jan 1839. By then, a few months earlier, both Friedrich Bessel and Friedrich Struve had been recognized as first for their measurements of stellar parallaxes. Alpha Centauri can be observed from the Cape, though not from Britain. It is now known to be the nearest star to the Sun, but is still so distant that its light takes 4.5 years to reach us. As Scottish Astronomer Royal in 1834, he worked diligently at the Edinburgh observatory for ten years, making over 60,000 observations of star positions before his death in 1844. *TIS

1808 Victoire Louis Athanase Dupré (December 28 1808 ; August 10 1869 ) was a French mathematician and physicist.
He worked on number theory and in the 1860s with thermodynamics and from him comes the textbook mécanique Théorie de la Chaleur (1869), which is essentially the distribution of this then-new field of knowledge in France contributed. Together with his son Paul Dupré experimental research, he examined the capillary and the surface tension of liquids. This work also led to a formulation of Young's equation which is known today as the Young-Dupré equation. *Wik

1828 Henry R. Rowlands becomes the first American to patent a device for walking on water. Since that time there have been at least one-hundred other patents approved in the US for similar devices. All seem to be inspired by the earliest known design (Jesus excepted) by Leonardo da Vinci in the late Fifteenth Century.

1873 William Draper Harkins (28 Dec 1873; 7 Mar 1951) American nuclear chemist who was one of the first to investigate the structure and fusion reactions of the nucleus. In 1920, Harkins predicted the existence of the neutron, subsequently discovered by Chadwick's experiment. He made pioneering studies of nuclear reactions with Wilson cloud chambers. In the early 1930's, (with M.D. Kamen) he built a cyclotron. Harkins demonstrated that in neutron bombardment reactions the first step in neutron capture is the formation of an "excited nucleus" of measurable lifetime, which subsequently splits into fragments. He also suggested that subatomic energy might provide enough energy to power the Sun over its lifetime.*TIS

1882 Sir Arthur Stanley Eddington (28 Dec 1882; 22 Nov 1944) English astrophysicist, and mathematician known for his work on the motion, distribution, evolution and structure of stars. He also interpreted Einstein's general theory of relativity. He was one of the first to suggest (1917) conversion of matter into radiation powered the stars. In 1919, he led a solar eclipse expedition which confirmed the predicted bending of starlight by gravity. He developed an equation for radiation pressure. In 1924, he derived an important mass-luminosity relation. He also studied pulsations in Cepheid variables, and the very high densities of white dwarfs. He sought fundamental relationships between the prinicipal physical constants. Eddington wrote many books for the general reader, including Stars and Atoms. *TIS One of my favorite stories about Eddington is this one: Ludwick Silberstein approached Eddington and told him that people believed he was one of only three people in the world who understood general relativity, and that included Einstein. When Eddington didn't respond for a moment he prodded, come on, don't be modest, and Eddington replied, "Oh, no. It's not that. I was just trying to figure out who the third was?" *Mario Livio, Brilliant Blunders

1898 Carl-Gustaf Arvid Rossby (28 Dec 1898; 19 Aug 1957) Swedish-U.S. meteorologist who first explained the large-scale motions of the atmosphere in terms of fluid mechanics. His work contributed to developing meteorology as a science. Rossby first theorized about the existence of the jet stream in 1939, and that it governs the easterly movement of most weather. U.S. Army Air Corps pilots flying B-29 bombing missions across the Pacific Ocean during World War II proved the jet stream's existence. The pilots found that when they flew from east to west, they experienced slower arrival times and fuel shortage problems. When flying from west to east, however, they found the opposite to be true. Rossby created mathematical models (Rossby equations) for computerized weather prediction (1950). *TIS

1903 John von Neumann is born in Budapest, Hungary.(28 Dec 1903, 8 Feb 1957) His prodigious abilities were recognized in the early childhood. He obtained a degree in chemical engineering attending the University of Berlin (1921-1923) and the Technische Hochschule in Zurich (1923-1926). *CHM
He made important contributions in quantum physics, logic, meteorology, and computer science. He invented game theory, the branch of mathematics that analyses strategy and is now widely employed for military and economic purposes. During WW II, he studied the implosion method for bringing nuclear fuel to explosion and he participated in the development of the hydrogen bomb. He also set quantum theory upon a rigorous mathematical basis. In computer theory, von Neumann did much of the pioneering work in logical design, in the problem of obtaining reliable answers from a machine with unreliable components, the function of "memory," and machine imitation of "randomness." *TIS

1929 Maarten Schmidt (28 Dec 1929, ) Dutch-born American astronomer who in 1963 discovered quasars (quasi-stellar objects). The hydrogen spectrum of these starlike objects shows a huge redshift, which indicates they are more distant than normal stars, travelling away at greater speed, and are among the oldest objects observed. In turn, this indicates they existed only when the universe was very young, and provides evidence against the steady state theory of Fred Hoyle. Schmidt is currently seeking to find the redshift above which there are no quasars, and he also studies x-ray and gamma ray sources.*TIS

DEATHS
1663 Francesco Maria Grimaldi (2 Apr 1618, 28 Dec 1663) Italian mathematician and physicist who studied the diffraction of light. He observed the image on a screen in a darkened room of a tiny beam of sunlight after it passed pass through a fine screen (or a slit, edge of a screen, wire, hair, fabric or bird feather). The image had iridescent fringes, and deviated from a normal geometrical shadow. He coined the name diffraction for this change of trajectory of the light passing near opaque objects (though, more specifically, it may have been interferences with two close sources that he observed). This provided evidence for later physicists to support the wave theory of light. With Riccioli, he investigated the object in free fall (1640-50), and found that distance of fall was proportional to the square of the time taken.*TIS

1827 Robert Woodhouse (28 April 1773 – 23 December 1827) was an English mathematician. His earliest work, entitled the Principles of Analytical Calculation, was published at Cambridge in 1803. In this he explained the differential notation and strongly pressed the employment of it; but he severely criticized the methods used by continental writers, and their constant assumption of non-evident principles. This was followed in 1809 by a trigonometry (plane and spherical), and in 1810 by a historical treatise on the calculus of variations and isoperimetrical problems. He next produced an astronomy; of which the first book (usually bound in two volumes), on practical and descriptive astronomy, was issued in 1812, and the second book, containing an account of the treatment of physical astronomy by Pierre-Simon Laplace and other continental writers, was issued in 1818.
He became the Lucasian Professor of Mathematics in 1820, and subsequently the Plumian professor in the university. As Plumian Professor he was responsible for installing and adjusting the transit instruments and clocks at the Cambridge Observatory.[3] He held that position until his death in 1827. *Wik

1871 John Henry Pratt (4 June 1809 - 28 December 1871) was a British clergyman and mathematician who devised a theory of crustal balance which would become the basis for the isostasy principle. *Wik

1896 Horatio (Emmons) Hale (3 May 1817, 28 Dec 1896) was an American anthropologistwhose contributions to the science of ethnology, included his theory of the origin of the diversities of human languages and dialectsa theory suggested by his study of child languages (the languages invented by little children). He emphasized the importance of languages as tests of mental capacity and as criteria for the classification of human groups. Hale was the first to discover that the Tutelos of Virginia belonged to the Siouan family, and to identify the Cherokee as a member of the Iroquoian family of speech. He sailed with the scientific corps of the Wilkes Exploring Expedition (1838-42) collecting linguistic materials. He used the drift of the Polynesian tongue as a clue to the migration of this race. *TIS

1919 Johannes Robert Rydberg, (‘Janne’ to his friends), (November 8, 1854 – December 28, 1919), was a Swedish physicist mainly known for devising the Rydberg formula, in 1888, which is used to predict the wavelengths of photons (of light and other electromagnetic radiation) emitted by changes in the energy level of an electron in a hydrogen atom.
The physical constant known as the Rydberg constant is named after him, as is the Rydberg unit. Excited atoms with very high values of the principal quantum number, represented by n in the Rydberg formula, are called Rydberg atoms. Rydberg's anticipation that spectral studies could assist in a theoretical understanding of the atom and its chemical properties was justified in 1913 by the work of Niels Bohr (see hydrogen spectrum). An important spectroscopic constant based on a hypothetical atom of infinite mass is called the Rydberg (R) in his honour. *Wik

1923 Gustave Eiffel (15 Dec 1832, 28 Dec 1923) French civil engineer who specialized in metal structures, known especially for the Eiffel Tower in Paris. He built his first of his iron bridges at Bordeaux (1858) and was among the first engineers to build bridge foundations using compressed-air caissons. His work includes designing the rotatable dome for Nice Observatory on the summit of Mont Gros (1886), and the framework for the Statue of Liberty now in New York Harbor. After building the Eiffel Tower (1887-9), which he used for scientific research on meteorology, aerodynamics and radio telegraphy, he also built the first aerodynamic laboratory at Auteuil, outside Paris, where he pursued his research work without interruption during WW I. *TIS

1964 Edwin Bidwell Wilson (25 April 1879 in Hartford, Connecticut, USA - 28 Dec 1964 in Brookline, Massachusetts, USA) Wilson graduated from Yale with a Ph.D. in 1901 and, in the same year, a textbook which he had written on vector analysis was published. Vector analysis (1901) was based on Gibbs' lectures and , "This beautiful work, published when Wilson was only twenty-two years old, had a profound and lasting influence on the notation for and the use of vector analysis." Wilson had been inspired by Gibbs to work on mathematical physics and he began to write papers on mechanics and the theory of relativity. In 1912 Wilson published the first American advanced calculus text. World War I had seen another move in Wilson's research interests for he had undertaken war work which involved aerodynamics and this led him to study the effects of gusts of wind on a plane. In 1920 he published his third major text Aeronautics and gathered round him a group of students working on this topic.
Wilson had already worked in a number of quite distinct areas and his work on aeronautics did not become the major topic for the rest of his career. Not long after the publication of his important text on Aeronautics his interests moved again, this time towards probability and statistics. He did not study statistics for its own, however, but he was interested in applying statistics both to astronomy and to biology. He was the first to study confidence intervals, later rediscovered by Neyman. In 1922 Wilson left the Massachusetts Institute of Technology to become Professor of Vital Statistics at the Harvard School of Public Health. He continued to hold this post until he retired in 1945, when he became professor emeritus. After he retired, Wilson spent a year in Glasgow, Scotland when he was Stevenson lecture on Citizenship. From 1948 he was a consultant to the Office of Naval Research in Boston. *SAU

Friday, 27 December 2019

On This Day in Math - December 27

Jacob Bernoulli's tomb marker

At ubi materia, ibi Geometria.
Where there is matter, there is geometry.

~Johannes Kepler

The 361st day of the year, 2³⁶¹ is an apocalyptic number, it contains 666. 2³⁶¹=4697085165547666455778961193578674054751365097816639741414581943064418050229216886927397996769537406063869952 That's 109 digits.

One of Ramanujan's many approximations of pi was (9²+ (19²/22))^1/4, and 361 = 19²

and as 361 is the last year day that is a perfect square, important to point out for students that all perfect squares are also the sum of consecutive triangular numbers, 361= 171 + 190

EVENTS
1612 Galileo observed Neptune, but did not recognize it as a planet. Galileo's drawings show that he first observed Neptune on December 28, 1612, and again on January 27, 1613. On both occasions, Galileo mistook Neptune for a fixed star when it appeared very close—in conjunction—to Jupiter in the night sky; hence, he is not credited with Neptune's discovery. (The official discovery is usually cited as September 23, 1846, Neptune was discovered within 1° of where Le Verrier had predicted it to be.) During the period of his first observation in December 1612, Neptune was stationary in the sky because it had just turned retrograde that very day. This apparent backward motion is created when the orbit of the Earth takes it past an outer planet. Since Neptune was only beginning its yearly retrograde cycle, the motion of the planet was far too slight to be detected with Galileo's small telescope.*Wik

In 1831, Charles Darwin set sail from Plymouth harbour on his voyage of scientific discovery aboard the HMS Beagle, a British Navy ship. The Captain Robert FitzRoy was sailing to the southern coast of South America in order to complete a government survey. Darwin had an unpaid position as the ship's naturalist, at age 22, just out of university. Originally planned to be at sea for two years, the voyage lasted five years, making stops in Brazil, the Galapogos Islands, and New Zealand. From the observations he made and the specimens he collected on that voyage, Darwin developed his theory of biological evolution through natural selection, which he published 28 years after the Beagle left Plymouth. Darwin laid the foundation of modern evolutionary theory. *TIS

In 1956, the formerly believed "law" of conservation of parity was disproved in the first successful results from an experiment conducted by Madame Chien-Shiung Wu at Columbia University on the beta-decay of cobalt-60. It had been suggested in a paper published by Lee and Yang on 1 Oct 1956. There had been problems to overcome working with the cobalt sample and detectors in a vacuum at a working temperature of one-hundredth of a kelvin. Wu's team repeated the experiment, doing maintenance on the apparatus as necessary, until on 9 Jan 1957 further measurements confirmed the initial results. Leon Lederman performed an independent test of parity with Columbia's cyclotron. They held a press conference on 15 Jan 1957.*TIS

BIRTHS
1571 Johannes Kepler (27 Dec 1571; 15 Nov 1630) German astronomer who formulated three major laws of planetary motion which enabled Isaac Newton to devise the law of gravitation. Working from the carefully measured positions of the planets recorded by Tycho Brahe, Kepler mathematically deduced three relationships from the data: (1) the planets move in elliptical orbits with the Sun at one focus; (2) the radius vector sweeps out equal areas in equal times; and (3) for two planets the squares of their periods are proportional to the cubes of their mean distances from the sun. Kepler suggested that the tides were caused by the attraction of the moon. He believed that the universe was governed by mathematical rules, but recognized the importance of experimental verification.*TIS

1654 Jacob Jacques Bernoulli (27 Dec 1654; 16 Aug 1705) was a Swiss mathematician and astronomer who was one of the first to fully utilize differential calculus and introduced the term integral in integral calculus. Jacob Bernoulli's first important contributions were a pamphlet on the parallels of logic and algebra (1685), work on probability in 1685 and geometry in 1687. His geometry result gave a construction to divide any triangle into four equal parts with two perpendicular lines. By 1689 he had published important work on infinite series and published his law of large numbers in probability theory. He published five treatises on infinite series (1682 - 1704). Jacob was intrigued by the logarithmic spiral and requested it be carved on his tombstone. He was the first of the Bernoulli family of mathematicians. *TIS (see more about the family of Bernoulli's at the Renaissance Mathematicus )

Even as the finite encloses an infinite series

And in the unlimited limits appear,

So the soul of immensity dwells in minutia

And in the narrowest limits no limit in here.

What joy to discern the minute in infinity!

The vast to perceive in the small, what divinity!

Ars Conjectandi

1773 Sir George Cayley (27 Dec 1773; 15 Dec 1857)(6th Baronet ) English aeronautical pioneer who built the first successful man-carrying glider (1853). He made extensive anatomical and functional studies of bird flight. By measuring bird and human muscle masses, he realized it would be impossible for humans to strap on a pair of wings and take to the air. His further studies in the principles of lift, drag and thrust founded the science of aerodynamics from which he discovered stabilizing flying craft required both vertical and horizontal tail rudders, that concave wings produced more lift than flat surfaces and that swept-back wings provided greater stability. Cayley also invented the caterpillar tractor (1825), automatic railroad crossing signals, self-righting lifeboats, and an expansion-air (hot-air) engine.
*TIS (He was a distant cousin of the father of mathematician Arthur Cayley)

1915 Jacob Lionel Bakst Cooper (27 December 1915, Beaufort West, Cape Province, South Africa, 8 August 1979, London, England) was a South African mathematician who worked in operator theory, transform theory, thermodynamics, functional analysis and differential equations.*Wik

DEATHS
1771 Henri Pitot (3 May 1695, 27 Dec 1771) French hydraulic engineer who invented the Pitot tube (1732), an instrument to measure flow velocity either in liquids or gases. With subsequent improvements by Henri Darcy, its modern form is used to determine the airspeed of aircraft. Although originally a trained mathematician and astronomer, he became involved with an investigation of the velocity of flowing water at different depths, for which purpose he first created the Pitot tube. He disproved the prevailing belief that the velocity of flowing water increased with depth. Pitot became an engineer in charge of maintenance and construction of canals, bridges, drainage projects, and is particularly remembered for his kilometer-long Roman-arched Saint-Clément Aqueduct (1772) at Montpellier, France. *TIS

1930 Gyula Farkas (28 March 1847 in Sárosd, Fejér County, Hungary - 27 Dec 1930 in Pestszentlorinc, Hungary) He is remembered for Farkas theorem which is used in linear programming and also for his work on linear inequalities. In 1881 Gyula Farkas published a paper on Farkas Bolyai's iterative solution to the trinomial equation, making a careful study of the convergence of the algorithm. In a paper published three years later, Farkas examined the convergence of more general iterative methods. He also made major contributions to applied mathematics and physics, particularly in the areas of mechanical equilibrium, thermodynamics, and electrodynamics.*SAU

1973 Raymond Woodard Brink (4 Jan 1890 in Newark, New Jersey, USA - 27 Dec 1973 in La Jolla, California, USA) was an American mathematician who studied at Kansas State University, Harvard and Paris. He taught at the University of Minnesota though he spent a year in Edinburgh in 1919. He worked on the convergence of series. *SAU

1992 Alfred Hoblitzelle Clifford (July 11, 1908 – December 27, 1992) was an American mathematician who is known for Clifford theory and for his work on semigroups. The Alfred H. Clifford Mathematics Research Library at Tulane University is named after him.*Wik

1995 Boris Vladimirovich Gnedenko (January 1, 1912 - December 27, 1995) was a Soviet mathematician and a student of Andrey Nikolaevich Kolmogorov. He was born in Simbirsk (now Ulyanovsk), Russia, and died in Moscow. He is perhaps best known for his work with Kolmogorov, and his contributions to the study of probability theory. Gnedenko was appointed as Head of the Physics, Mathematics and Chemistry Section of the Ukrainian Academy of Sciences in 1949, and also became Director of the Kiev Institute of Mathematics in the same year.*Wik

1996 Sister Mary Celine Fasenmyer, R.S.M., (October 4, 1906, Crown, Pennsylvania – December 27, 1996, Erie, Pennsylvania) was a mathematician. She is most noted for her work on hypergeometric functions and linear algebra.*Wik

2006 Peter L. Hammer (December 23, 1936 - December 27, 2006) was an American mathematician native to Romania. He contributed to the fields of operations research and applied discrete mathematics through the study of pseudo-Boolean functions and their connections to graph theory and data mining.*Wik

Thursday, 26 December 2019

On This Day in Math - December 26

A young man passes from our public schools to the universities, ignorant almost of the elements of every branch of useful knowledge.
~Charles Babbage

The 360th day of the year; Bryant Tuckerman found the Mersenne prime M19937 (which has 6000 digits) using an IBM360. *Prime Curios

360 is also the number of degrees in a full circle, and there is a (rather new) word for two angles that sum to 360 degrees. They are called "explementary" .

360 is a highly composite number, it has 24 divisors, more than any other number of the year, in fact any number that is below twice its size.

It is the smallest number that is divisible by nine of the ten numbers 1-10 (not divisible by 7) What is next, students?

There are 360 possible rook moves on a 6x6 chess board.*Derek Orr

360 is centered on the 360th digit of pi (Also from Derek)[However 360 does occur once earlier centered at position 286.]

EVENTS 1638 Fermat, in a letter to Mersenne, stated that he had a method of solving any questions on aliquot parts. Frenicle would respond through Mersenne by challenging Fermat to find a perfect number of 20 or 21 digits, under the then common belief that a perfect number existed between any two consecutive powers of ten. Fermat's answer, in March was to say that there are none. *L E Dickson, History of the Theory of Numbers

1837 Charles Babbage completed his “Calculating Engine” manuscript. *VFR

1843 John Graves write to William Rowan Hamilton that he has invented an eight-dimension normed division algebra he called "Octaves" Within a few months, Hamilton would realize that the octonions were not associative. This would lead to the first use of the term "associative" by Hamilton in 1844. (Except for matrices, which were not generally considered as "numbers", there were no common non-associative systems at that time) *Joan Baez Rankin Lecture of September 17, 2008 Glascow
The complete Volume Two of the Proceedings of the Royal Irish Academy were released in 1844, but the paper had been read on November 13, 1843; over a full month before Grave's letter. Hamilton created the phrase in explaining that although the Quaterninons maintained the distributive property, "yet the commutative character is lost," and then adds, "another important property of the old multiplication is preserved ... which may be called the associative character of the operation."
,

1864 The official seal of MIT was adopted on December 26, 1864. The craftsman at the anvil and the scholar with a book on the seal of the Massachusetts Institute of Technology embody the educational philosophy of William Barton Rogers and other incorporators of MIT as stated in their 1860 proposal Objects and Plan of an Institute of Technology. *MIT History

1898 Radium discovered by Pierre and Marie Curie. *VFR Actually, it seems this was the date of their announcement of the discovery(which must have occurred a few days earlier. They created the name radium for their element. This was their second discovery in the first year of her research on her thesis. They had also discovered Polonium earlier in the year.

In 1906, the world's first full-length feature film, the 70-min Story of the Kelly Gang was presented in the Town Hall at Melbourne, Australia, where it had been filmed at a cost of £450. It preceded D.W. Griffith's The Birth of a Nation by nine years. The subject of the Australian movie was Ned Kelly, a bandit who lived 1855 to 1880. The film toured through Australia for over 20 years, and abroad in New Zealand and Britain. Since some people, including politicians and police viewed the content of the film as glorifying the criminals, the movie was banned (1907) in Benalla and Wangaratta and also in Victoria (1912). Only fragments totalling about 10 minutes of the original nitrate film have survived to the present.*TIS

1951 Kurt Godel delivered the Gibbs Lecture, “Some Basic Theorems on the Foundations of Mathematics and their Philosophical Implications,” to the annual AMS meeting at Brown University. *VFR

1982 TIME Names a Non-Human “Man of the Year”
TIME magazine's editors selected the Personal Computer for “Machine of the Year,” in lieu of their well-known “Man of the Year” award. The computer beat out U.S. President Ronald Reagan, U.K. prime minister Margaret Thatcher and Prime Minister of Israel, Menachem Begin. The planet Earth became the second non-human recipient for the award in 1988. The awards have been given since 1927. The magazine's essay reported that in 1982, 80% of Americans expected that "in the fairly near future, home computers will be as commonplace as television sets or dishwashers.” In 1980, 724,000 personal computers were sold in the United States, according to Time. The following year, that number doubled to 1.4 million. *CHM

2017 On the day after Christmas in the Germantown Church of Christ, in a suburb just Southeast of Memphis, a miracle, of sorts, happened. A computer began running a program that had been installed years before by a 20 year Deacon of the Church, John Pace, discovered the largest known prime number. The new "largest" prime was 23,249,425 digits long. The number is one less than the product of 77,232,917 twos multiplied together, and thus has the name M77232917. The computer then did one thing it was programmed to do; it forwarded the number to the Gimps (Great Internet Mersenne Prime Search) Project home computer. It failed to do the second thing it was supposed to do, notify the deacon that his computer had succeeded in finding a candidate for the largest known Mersenne Prime. He had to learn the news from a congratulatory email from the founder of the GIMPS project. The public was informed of the new largest prime on Jan 3 of 2018. *NY TIMES

BIRTHS 1532 Wilhelm Xylander (born Wilhelm Holtzman, graecized to Xylander) (December 26, 1532 – February 10, 1576) was a German classical scholar and humanist.
Xylander was the author of a number of important works. He translated the first six books of Euclid into German with notes, the Arithmetica of Diophantus, and the De quattuor mathematicis scientiis of Michael Psellus into Latin. *Wik

1780 Mary Fairfax Greig Somerville (26 Dec 1780 in Jedburgh, Roxburghshire, Scotland - 29 Nov 1872 in Naples, Italy) Somerville wrote many works which influenced Maxwell. Her discussion of a hypothetical planet perturbing Uranus led Adams to his investigation. Somerville College in Oxford was named after her.*SAU

1791 Charles Babbage born. *VFR (26 Dec 1791; 18 Oct 1871) English mathematician and pioneer of mechanical computation, which he pursued to eliminate inaccuracies in mathematical tables. By 1822, he had a small calculating machine able to compute squares. He produced prototypes of portions of a larger Difference Engine. (Georg and Edvard Schuetz later constructed the first working devices to the same design which were successful in limited applications.) In 1833 he began his programmable Analytical Machine, a forerunner of modern computers. His other inventions include the cowcatcher, dynamometer, standard railroad gauge, uniform postal rates, occulting lights for lighthouses, Greenwich time signals, heliograph opthalmoscope. He also had an interest in cyphers and lock-picking.*TIS

1861 Frederick Engle born in Germany. He became the closest student of the Norwegian mathe¬matician Sophus Lie. Engle was also the ﬁrst to translate Lobachevsky’s work into a Western language (German). *VFR

1900 Antoni Zygmund (26 Dec 1900; 30 May 1992) Polish-born mathematician who created a major analysis research centre at Chicago, and recognized in 1986 for this with the National Medal for Science. In 1940, he escaped with his wife and son from German controlled Poland to the USA. He did much work in harmonic analysis, a statistical method for determining the amplitude and period of certain harmonic or wave components in a set of data with the aid of Fourier series. Such technique can be applied in various fields of science and technology, including natural phenomena such as sea tides. He also did major work in Fourier analysis and its application to partial differential equations. Zygmund's book Trigonometric Series (1935) is a classic, definitive work on the subject*TIS

1903 Lancelot Stephen Bosanquet (26 Dec 1903 in St. Stephen's-by-Saltash, Cornwall, England - 10 Jan 1984 in Cambridge, Cambridgeshire, England) Bosanquet wrote many papers on the convergence and summability of Fourier series. He also wrote on the convergence and summability of Dirichlet series and studied specific kinds of summability such as summability factors for Cesàro means. His later work on integrals include two major papers on the Laplace-Stieltjes integral published in 1953 and 1961. Other topics he studied included inequalities, mean-value theorems, Tauberian theorems, and convexity theorems. *SAU

1937 John Horton Conway (born 26 December 1937, ) is a prolific mathematician active in the theory of finite groups, knot theory, number theory, combinatorial game theory and coding theory. He has also contributed to many branches of recreational mathematics, notably the invention of the cellular automaton called the Game of Life.
Conway is currently Professor of Mathematics and John Von Neumann Professor in Applied and Computational Mathematics at Princeton University. He studied at Cambridge, where he started research under Harold Davenport. He received the Berwick Prize (1971),[1] was elected a Fellow of the Royal Society (1981),[2] was the first recipient of the Pólya Prize (LMS) (1987),[1] won the Nemmers Prize in Mathematics (1998) and received the Leroy P. Steele Prize for Mathematical Exposition (2000) of the American Mathematical Society. He has an Erdős number of one.*Wik Conway is known for his sense of humor, and the last proof in his "On Numbers and Games" is this:
Theorem 100; This is the last Theorem in this book.
The Proof is Obvious.
In April of 2020, Conway was exposed to the corona virus and took a fever around the 8th of April. He had suffered from ill health for an extended time, and in three days, on April 11, 2020 he died at his home in New Jersey.

I really enjoyed Siobhan Roberts biography of Conway. You may, too.

DEATHS
1624 Simon Marius (10 Jan 1573, 26 Dec 1624) (Also known as Simon Mayr) German astronomer, pupil of Tycho Brahe, one of the earliest users of the telescope and the first in print to make mention the Andromeda nebula (1612). He studied and named the four largest moons of Jupiter as then known: Io, Europa, Ganymede and Callisto (1609) after mythological figures closely involved in love with Jupiter. Although he may have made his discovery independently of Galileo, when Marius claimed to have discovered these satellites of Jupiter (1609), in a dispute over priority, it was Galileo who was credited by other astronomers. However, Marius was the first to prepare tables of the mean periodic motions of these moons. He also observed sunspots in 1611 *TIS You can find a nice blog about the conflict with Galileo by the Renaissance Mathematicus.

1931 Melvil Dewey (10 Dec 1851, 26 Dec 1931) American librarian who developed library science in the U.S., especially with his system of classification, the Dewey Decimal Classification (1876), for library cataloging. His system of classification (1876) uses numbers from 000 to 999 to cover the general fields of knowledge and designating more specific subjects by the use of decimal points. He was an activist in the spelling reform and metric system movements. Dewey invented the vertical office file, winning a gold medal at the 1893 World's Fair. It was essentially an enlarged version of a card catalogue, where paper documents hung vertically in long drawers. *TIS

2006 Martin David Kruskal (September 28, 1925 – December 26, 2006) was an American mathematician and physicist. He made fundamental contributions in many areas of mathematics and science, ranging from plasma physics to general relativity and from nonlinear analysis to asymptotic analysis. His single most celebrated contribution was the discovery and theory of solitons. His Ph.D. dissertation, written under the direction of Richard Courant and Bernard Friedman at New York University, was on the topic "The Bridge Theorem For Minimal Surfaces." He received his Ph.D. in 1952.
In the 1950s and early 1960s, he worked largely on plasma physics, developing many ideas that are now fundamental in the field. His theory of adiabatic invariants was important in fusion research. Important concepts of plasma physics that bear his name include the Kruskal–Shafranov instability and the Bernstein–Greene–Kruskal (BGK) modes. With I. B. Bernstein, E. A. Frieman, and R. M. Kulsrud, he developed the MHD (or magnetohydrodynamic) Energy Principle. His interests extended to plasma astrophysics as well as laboratory plasmas. Martin Kruskal's work in plasma physics is considered by some to be his most outstanding.
In 1960, Kruskal discovered the full classical spacetime structure of the simplest type of black hole in General Relativity. A spherically symmetric black hole can be described by the Schwarzschild solution, which was discovered in the early days of General Relativity. However, in its original form, this solution only describes the region exterior to the horizon of the black hole. Kruskal (in parallel with George Szekeres) discovered the maximal analytic continuation of the Schwarzschild solution, which he exhibited elegantly using what are now called Kruskal–Szekeres coordinates.
This led Kruskal to the astonishing discovery that the interior of the black hole looks like a "wormhole" connecting two identical, asymptotically flat universes. This was the first real example of a wormhole solution in General Relativity. The wormhole collapses to a singularity before any observer or signal can travel from one universe to the other. This is now believed to be the general fate of wormholes in General Relativity.
Martin Kruskal was married to Laura Kruskal, his wife of 56 years. Laura is well known as a lecturer and writer about origami and originator of many new models. Martin, who had a great love of games, puzzles, and word play of all kinds, also invented several quite unusual origami models including an envelope for sending secret messages (anyone who unfolded the envelope to read the message would have great difficulty refolding it to conceal the deed).
His Mother, Lillian Rose Vorhaus Kruskal Oppenheimer was an American origami pioneer. She popularized origami in the West starting in the 1950s, and is credited with popularizing the Japanese term origami in English-speaking circles, which gradually supplanted the literal translation paper folding that had been used earlier. In the 1960s she co-wrote several popular books on origami with Shari Lewis.*wik

Wednesday, 25 December 2019

On This Day in Math - December 25

God Bless Us, Everyone

Me, and Tiny Tim

The 359th day of the year; 359 is a Sophie Germain prime. If you start with n=89 and iterate 2n+1 you will get a string of primes that includes 359. (How many in all?)

It is also the smallest Sophie Germain prime whose reversal, 953 is also a Sophie Germain prime
and Sadly, the last day of the year that is prime. (On most years this year day occurs on Christmas Day, a fitting day for the last prime day of the year .)

EVENTS
1843 Sir Henry Cole British industrial designer, museum director and writer who produced the first commercial Christmas card. In 1843, wishing to save much handwriting of seasonal correspondence, Cole introduced the world's first commercial Christmas card. He commissioned artist John Callcott Horsley to make the artwork for 1000 hand-coloured lithographs. (Individuals' homemade Christmas cards had existed earlier.) (See Image at top)

1640 Fermat's theorem on sums of two squares states that an odd prime p can be expressed as:

p= x² + y² with x and y integers, if and only if $ p\equiv 1 mod 4 $

The prime numbers for which this is true are called Pythagorean primes. For example, the primes 5, 13, 17, 29, 37 and 41 are all congruent to 1 modulo 4,

Albert Girard was the first to make the observation, describing all positive integral numbers (not necessarily primes) expressible as the sum of two squares of positive integers; this was published in 1625.The statement that every prime p of the form 4n+1 is the sum of two squares is sometimes called Girard's theorem. For his part, Fermat wrote an elaborate version of the statement (in which he also gave the number of possible expressions of the powers of p as a sum of two squares) in a letter to Marin Mersenne dated December 25, 1640: for this reason this version of the theorem is sometimes called Fermat's Christmas theorem. *Wik

1656 Huygens (who was a bachelor) spent Christmas Day making the ﬁrst model of a pendulum clock. *VFR(And then he was visited by three spirits.... oops, wrong story)

In 1741, the Centigrade temperature scale was devised by astronomer Anders Celsius (1701-44) and incorporated into a Delisle thermometer at Uppsala in Sweden. Celsius divided the fixed-point range of the Fahrenheit scale (the freezing and boiling temperatures of water) into 100 equal divisions, but curiously set the freezing point at 100 and the boiling point at 0. This reverse scaling was changed to match the sense of the other temperature scales after Celsius's death.*TIS

1758 Halley’s comet ﬁrst sighted after he predicted its return. After Newton explained planetary motion, he suggested that comets could have elongated elliptical orbits. Halley’s comet has eccentricity 0.9675. [UMAP Journal, 4(1983), p. 162] *VFR
In 1758, the predicted return of Halley's comet was first sighted by German farmer and amateur astronomer, Johann Georg Palitzsch, as a faint object in Pisces. Edmund Halley had predicted in 1705 the return of the comet to the Earth's vicinity every 75.5 years. For the first time the scientific prediction had been proven. Halley himself had died 16 years before this new event. Palitzsch also observed the 6 Jun 1761 transit of Venus, when he saw a black band linking Venus and the Sun near the beginning and end of the transit ("black drop effect") and correctly interpreted this as evidence that Venus possessed an atmosphere. He also measured the period of the variation of the brightness of the star Algol. *TIS
The BAYEUX TAPESTRY (Tapisserie de la Reine Mathilde) includes a clear picture of Halley's Comet, as shown on the stamp below.

and here is a Blog regarding the return in 1758.

In 1780, Luigi Galvani recorded, "The electric fluid should be considered a means to the nervo-muscular force." He reached this conclusion from work in his laboratory in Bologna, Italy, after a series of experiments and his accidental discovery that muscles are operated by electrical stimulation of nerves. He worked diligently along these lines, but waited for eleven years before he published the results and an ingenious and simple theory. His theory was that of a nervous electric fluid, secreted by the brain, conducted by the nerves, and stored in the muscles. Though his ideas were abandoned by scientists on account of later discoveries, his work opened the way to new research in the physiology of muscle and nerve and pioneered the subject of electrophysiology. *TIS

1884 On the first Christmas after it was printed, the future classic, Flatland, was reviewed in the Times UK, which gave it a less than sterling review.

In 1999, space shuttle Discovery's astronauts finished their maintenance work on the Hubble Space Telescope, installing correcting optics to repair problems due to a design flaw in the mirror. The first images the Hubble Telescope took after its original launch were disappointingly fuzzy, but after this repair mission the instrument returned crisp images of a clarity never before possible from terrestrial observatories *TIS

BIRTHS
1642 Isaac Newton born on Julian Calendar. (5 January 1643 New style) *VFR
Born 25 Dec 1642; died 20 Mar 1727. English physicist and mathematician, who made seminal discoveries in several areas of science, and was the leading scientist of his era. His study of optics included using a prism to show white light could be split into a spectrum of colours. The statement of his three laws of motion are fundamental in the study of mechanics. He was the first to describe the moon as falling (in a circle around the earth) under the same influence of gravity as a falling apple, embodied in his law of universal gravitation. As a mathematician, he devised infinitesimal calculus to make the calculations needed in his studies, which he published in Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy, 1687)*TIS

1763 Claude Chappe (25 Dec 1763; 23 Jan 1805) French engineer who invented the semaphore visual telegraph. He began experimenting in 1790, trying various types of telegraph. An early trial used telescopes, synchronised pendulum clocks and a large white board, painted black on the back, with which he succeeded in sending a message a few sentences long across a 16km (10mi) distance. To simplify construction, yet still easily visible to read from far away, he changed to using his semaphore telegraph in 1793. Smaller indicators were pivoted at each end of large horizontal member. The two indicators could each be rotated to stand in any of eight equally spaced positions. By setting them at different orientations, a set of corresponding codes was used to send a message.*TIS

1900 Antoni Szczepan Zygmund (25 Dec 1900 in Warsaw, Russian Empire (now Poland)
- 30 May 1992 in Chicago, Illinois, USA) Zygmund's work in harmonic analysis has application in the theory of waves and vibrations. He also did major work in Fourier analysis and its application to partial differential equations.*SAU

1905 Gottfried Maria Hugo Köthe (born 25 December 1905 in Graz; died 30 April 1989 in Frankfurt) was an Austrian mathematician working in abstract algebra and functional analysis.*SAU Köthe's best known work has been in the theory of topological vector spaces. In 1960, volume 1 of his seminal monograph Topologische lineare Räume was published (the second edition was translated into English in 1969). It was not until 1979 that volume 2 appeared, this time written in English. He also made contributions to the theory of lattices. *Wik

DEATHS
1921 Piers Bohl (October 23, 1865 – December 25, 1921) was a Latvian mathematician, who worked in differential equations, topology and quasi-periodic functions.
He was born in 1865 in Walk, Livonia, in the family of a poor Baltic German merchant. In 1884, after graduating from a German school in Viljandi, he entered the faculty of physics and mathematics at the University of Tartu. In 1893 Bohl was awarded his Master's degree. This was for an investigation of quasi-periodic functions. The notion of quasi-periodic functions was generalised still further by Harald Bohr when he introduced almost-periodic functions. *Wik

1929 Percy Alexander MacMahon (b. 26 September 1854, Sliema, Malta – 25 December 1929, Bognor Regis, England) was a mathematician, especially noted in connection with the partitions of numbers and enumerative combinatorics. MacMahon was elected a Fellow of the Royal Society in 1890. He received the Royal Society Royal Medal in 1900, the Sylvester Medal in 1919, and the Morgan Medal by the London Mathematical Society in 1923. MacMahon was the President of the London Mathematical Society from 1894 to 1896.
MacMahon is best known for his study of symmetric functions and enumeration of plane partitions; see MacMahon Master theorem. His two volume Combinatory analysis, published in 1915/16, is the first major book in enumerative combinatorics. MacMahon also did pioneering work in recreational mathematics and patented several successful puzzles.*WIK

1930 Eugen Goldstein (5 Sep 1850, 25 Dec 1930) German physicist who discovered and named canal rays (1886) which emerge through holes in the anodes of low-pressure electrical discharge tubes (later shown to be positively charged particles). Earlier, he coined the term "cathode ray" (1876) emitted from a cathode. He was the first to see that they could cast a shadow, and were emitted at right angles to the surface. He also investigated the wavelengths of light emitted by metals and oxides when canal rays impinge on them. When the Berlin Urania, opened in 1889 it had five scientific departments and a "science theatre", it was Goldstein who had recommended the "hall of physics in which the visitor could experiment on his own". Students of his that continued his work included Wien and Stark. *TIS

1941 Theodor Molien or Fedor Eduardovich Molin (September 10, 1861 - December 25, 1941) was a Baltic-German mathematician. He was born in Riga, Latvia, which at that time was a part of Russian Empire. Molien studied associative algebras and polynomial invariants of finite groups.*Wik

1944 Wilhelm Kutta was a German engineer who is best known for his work on the numerical solution of differential equations (the Runge-Kutta method).*SAU Kutta was born in Pitschen, Upper Silesia (today Byczyna, Poland). He attended the University of Breslau from 1885 to 1890, and continued his studies in Munich until 1894, where he became the assistant of Walther Franz Anton von Dyck. From 1898, he spent half a year at the University of Cambridge.[1] From 1899 to 1909 he worked again as an assistant of von Dyck in Munich; from 1909 to 1910 he was adjunct professor at the Friedrich Schiller University Jena. He was professor at the RWTH Aachen from 1910 to 1912. Kutta became professor at the University of Stuttgart in 1912, where he stayed until his retirement in 1935.
In 1901, he co-developed the Runge-Kutta method, used to solve ordinary differential equations numerically. He is also remembered for the Zhukovsky-Kutta aerofoil, the Kutta-Zhukovsky theorem and the Kutta condition in aerodynamics. Kutta died in Fürstenfeldbruck, Germany in 1944. *Wik

2000 Willard Van Orman Quine (June 25, 1908 – December 25, 2000) (known to intimates as "Van")[1] was an American philosopher and logician in the analytic tradition. From 1930 until his death 70 years later, Quine was continuously affiliated with Harvard University in one way or another, first as a student, then as a professor of philosophy and a teacher of mathematics, and finally as a professor emeritus who published or revised several books in retirement. He filled the Edgar Pierce Chair of Philosophy at Harvard from 1956 to 1978. A recent poll conducted among philosophers named Quine one of the five most important philosophers of the past two centuries.[2] He won the first Schock Prize in Logic and Philosophy in 1993, for "his systematical and penetrating discussions of how learning of language and communication are based on socially available evidence and of the consequences of this for theories on knowledge and linguistic meaning.*Wik

2018 Nancy Grace Roman (May 16, 1925..Nashville, Tennessee, U.S.-December 25, 2018 (aged 93)) was an American astronomer and one of the first female executives at NASA. She is known to many as the "Mother of Hubble" for her role in planning the Hubble Space Telescope. Throughout her career, Roman was also an active public speaker and educator, and an advocate for women in the sciences.
When Roman was eleven years old, she showed interest in astronomy by forming an astronomy club among her classmates in Nevada. She and her classmates got together once a week and learned about constellations from books. Although discouraged by those around her, Roman knew by the time she was in high school that she wanted to pursue her passion for astronomy. She attended Western High School in Baltimore where she participated in an accelerated program and was graduated in three years. *Wik

Tuesday, 24 December 2019

On This Day in Math - December 24

The travelers looked up to see an omen shining in the sky,
Earthrise: See 1968 below

The 358th day of the year; 358 is twice a prime, and the sum of six consecutive primes.

The sum of the first 358 prime numbers is itself a prime number.

and in case you were curious, the 358th digit of pi (after the decimal point) is 3.

EVENTS
1754 Euler writes to Muller in St Petersburg and describes d'Alembert as "the most argumentative man in the world," and calls him, "hated by everyone in Paris." *Thomas L. Hankins, Jean d'Alembert: science and the Englightenment; pg 58

1819 Bernard Bolzano was dismissed from his theological chair at the University of Prague and put under police supervision for his unorthodox religious views. In mathematics he helped remove the scandal of inﬁnitesimals from the calculus. *VFR

1849 Guass writes to the Astronomer Johann Franz Encke in response to Encke's remarks about the Frequency of Primes.

"Most Honored Friend!
. . .The kind communication of your remarks on the frequency of prime numbers
was interesting to me in more than one respect. You have reminded me of
my own pursuit of the same subject, whose first beginnings occurred a very long
time ago, in 1792 or 1793, when I had procured for myself Lambert’s supplement
to the table of logarithms. Before I had occupied myself with the finer
investigations of higher arithmetic, one of my first projects was to direct my
attention to the decreasing frequency of prime numbers, to which end I counted
them up in several chiliads (sets of a thousand) and recorded the results on one of the affixed white sheets. I soon recognized, that under all variations of this frequency, on average, it is nearly inversely proportional to the logarithm..."

Guass never published his results. The first published version of the Prime Number Theorem was by Legendre in 1798. *John Derbyshire, Prime Obsession

1899 the Physico-Mathematic Society of Kazan (Russia) celebrated a Jubilee in honor of the twenty-fifth year of professional and scientific service of its President, Professor A. Vasiliev. It is also the fifteenth year of his presidency. Professor Vasiliev has been an extraordinarily important figure in Russian science. Outside of Russia he has chiefly been known for his remarkable discourse on Lobachevski. *The American Mathematical Monthly, Vol. 7, No. 1 (Jan., 1900), p. 30

1906 First Long Range transmisson of voice: Reginald Aubrey Fessenden was a Canadian inventor and engineer with 300 patents. He broadcast the first program of voice and music. In 1893, Fessenden moved to Pittsburgh as the head of electrical engineering at the university, Fessenden read of Marconi's work and began experimenting himself. Marconi could only transmit Morse code. But Fessenden's goal was to transmit the human voice and music. He invented the "continuous wave": sound superimposed onto a radio wave for transmission. A radio receiver extracts the signal so the listener with the original sound. Fessenden made the first long-range transmissions of voice on Christmas Eve 1906 from a station at Brant Rock, Massachusetts, heard hundreds of miles out in the Atlantic.*TIS He used a 42 kHz radio frequency Alexanderson alternator which produced about 1kW of power. Although Fessenden's work made voice radio possible, it would take 10 years and the First World War before it became commonplace. Throughout this period, radio was still seen primarily as point-to-point communication between transmitting stations--a sort of wireless telephone. *CHM

1912 Irving Fisher (1867-1947), a Yale professor, patented an archiving system with index cards. On 1 Jul 1925, Fisher's own firm, the Index Visible Company, merged with its principal competitor to form Kardex Rand Co., later Remington Rand, still later Sperry Rand. Fisher earned about $$1 million$ for the invention, which grew to the princely sum of $$9 million$ before being lost in the stock market crash of 1929. Fisher is widely regarded as the greatest economist America has produced, who made much use of mathematics in his work.*TIS

1968 On Christmas Eve, the Apollo 8 astronauts saw the entirety of Earth for the first time. Turing their cameras to the Earth they took the first three pictures of the whole earth from space. The one above, by William Anders, has been called "the most influential environmental photograph ever taken." *Wik, NASA

In 2004, the Huygens probe began a 22-day descent towards Saturn's largest moon, Titan. It had been launched as part of the Cassini spacecraft in 1997, and together they entered Saturn's orbit in June 2004. As the paths of the spacecraft and Titan converged, Cassini ejected the Huygens probe, sending it on a 22-day coast toward the cloud-covered moon. It landed 14 Jan 2005, and sent back photgraphs of the moon's surface. Cassini will remain in orbit around Saturn until at least July 2008. The Cassini-Huygens mission to study Saturn and its 33 known moons resulted from an unprecedented cooperative effort between the NASA of the United States, the European Space Agency and Italy's space program, at a cost of $3.3 billion. *TIS

BIRTHS
1740 Anders Johan Lexell (December 24, 1740 – December 11, 1784 (Julian calendar: November 30)) was a Swedish-born Russian astronomer, mathematician, and physicist who spent most of his life in Russia where he is known as Andrei Ivanovich Leksel.
Lexell made important discoveries in polygonometry and celestial mechanics; the latter led to a comet named in his honor. La Grande Encyclopédie states that he was the prominent mathematician of his time who contributed to the spherical trigonometry with new and interesting solutions, which he took as a basis for his research of comet and planet motion. His name was given to one of the theorems about spherical triangles.
Lexell was one of the most prolific members of the Russian Academy of Sciences at that time, having published 66 papers in 16 years of his work there. A statement attributed to Leonhard Euler expresses high approval of Lexell's works: "Besides Lexell, such a paper could only be written by D'Alambert or me". Daniel Bernoulli also praised his work, writing in a letter to Johann Euler "I like Lexell's works, they are profound and interesting, and the value of them is increased even more because of his modesty, which adorns great men".
Lexell did not have a family and kept up a close friendship with Leonhard Euler and his family. He witnessed Euler's death at his house and succeeded him to the chair of the mathematics department at the Russian Academy of Sciences, but died the following year. The asteroid 2004 Lexell is named in his honour, as is the lunar crater Lexell.*Wik

1818 James Prescott Joule (24 Dec 1818; 11 Oct 1889) English physicist who established that the various forms of energy - mechanical, electrical, and heat - are basically the same and can be changed, one into another. Thus he formed the basis of the law of conservation of energy, the first law of thermodynamics. He discovered (1840) the relationship between electric current, resistance, and the amount of heat produced. In 1849 he devised the kinetic theory of gases, and a year later announced the mechanical equivalent of heat. Later, with William Thomson (Lord Kelvin), he discovered the Joule-Thomson effect. The SI unit of energy or work , the joule (symbol J), is named after him. It is defined as the work done when a force of 1 newton moves a distance of 1 metre in the direction of the force.*TIS

1822 Charles Hermite (24 Dec 1822; 14 Jan 1901) French mathematician whose work in the theory of functions includes the application of elliptic functions to provide the first solution to the general equation of the fifth degree, the quintic equation. In 1873 he published the first proof that e is a transcendental number. Hermite is known also for a number of mathematical entities that bear his name, Hermite polynomials, Hermite's differential equation, Hermite's formula of interpolation and Hermitian matrices. Poincaré is the best known of Hermite's students.*TIS

1838 Thorvald Nicolai Thiele (24 December 1838 – 26 September 1910) was a Danish astronomer, actuary and mathematician, most notable for his work in statistics, interpolation and the three-body problem. He was the first to propose a mathematical theory of Brownian motion. Thiele introduced the cumulants and (in Danish) the likelihood function; these contributions were not credited to Thiele by Ronald A. Fisher, who nevertheless named Thiele to his (short) list of the greatest statisticians of all time on the strength of Thiele's other contributions.
Thiele also was a founder and Mathematical Director of the Hafnia Insurance Company and led the founding of the Danish Society of Actuaries. It was through his insurance work that he came into contact with fellow mathematician Jørgen Pedersen Gram. Asteroid 843 Nicolaia is named in his honor. *Wik

1868 Emanuel Lasker (24 Dec 1868 in Berlinchen, Prussia (now Barlinek, Poland) - 11 Jan 1941 in New York, USA) Lasker became World Chess Champion in 1894 and held the championship until 1921. In mathematics he introduced the notion of a primary ideal. *SAU

1904 Sir William Hunter McCrea FRS (13 December 1904, Dublin – 25 April 1999) was an English astronomer and mathematician. He went to Trinity College, Cambridge in 1923 where he studied Mathematics, later gaining a PhD in 1929 under Ralph H. Fowler. He was later appointed a lecturer of Mathematics at the University of Edinburgh in 1929. He also served as reader and assistant professor at Imperial College London. In 1936 he became head of the mathematics department at the Queen's University of Belfast. After serving in the war, he joined the mathematics department at Royal Holloway College in 1944 (the McCrea Building on Royal Holloway's campus is named after him). In 1965, McCrea created the astronomy centre of the physics department at the University of Sussex.
In 1928, he studied Albrecht Unsöld's hypothesis, and discovered that three quarters of the Sun is made of Hydrogen, and about one quarter is Helium, with 1% being other elements. Previous to this many people thought the Sun consisted mostly of Iron. After this, people realized most stars consist of Hydrogen.
McCrea was president of the Royal Astronomical Society from 1961-3 and president of Section A of the British Association for the Advancement of Science from 1965-6. He was knighted in 1985. He won the Gold Medal of the Royal Astronomical Society in 1976. McCrea died on April 25, 1999 in Lewes. *Wik

1910 William Hayward Pickering (24 Dec 1910; 15 Mar 2004) Engineer and physicist, head of the team that developed Explorer 1, the first U.S. satellite. He collaborated with Neher and Robert Millikan on cosmic ray experiments in the 1930s, taught electronics in the 1930s, and was at Caltech during the war. He spent the rest of his career with the Jet Propusion Laboratory, becoming its Director (1954) with responsibility for the U.S. unmanned exploration of the planets and the solar system. Among these were the Mariner spacecraft to Venus and Mercury, and the Viking mission to Mars. The Voyager spacecraft yielded stunning photographs of the planets Jupiter and Saturn.*TIS

DEATHS
(How sad to be one of these people who died on Christmas Eve)
1872 William John Macquorn Rankine (5 Jul 1820, 24 Dec 1872) Scottish engineer and physicist and one of the founders of the science of thermodynamics, particularly in reference to steam-engine theory. As the chair (1855) of civil engineering and mechanics at Glasgow, he developed methods to solve the force distribution in frame structures. Rankine also wrote on fatigue in the metal of railway axles, on Earth pressures in soil mechanics and the stability of walls. He was elected a Fellow of the Royal Society in 1853. Among his most important works are Manual of Applied Mechanics (1858), Manual of the Steam Engine and Other Prime Movers (1859) and On the Thermodynamic Theory of Waves of Finite Longitudinal Disturbance. *TIS (Many students are not aware there is a absolute temperature scale called the Rankine, named for him)

1882 Johann Benedict Listing (25 July 1808 in Frankfurt am Main, Germany - 24 Dec 1882 in Göttingen, Germany)wrote one of the earliest texts on Topology. he studied the figure of the earth in minute detail; he made observations in meteorology, terrestrial magnetism, and spectroscopy; he wrote on the quantitative determination of sugar in the urine of diabetics; he promoted the nascent optical industry in Germany and better street lighting in Göttingen; he travelled to the world exhibitions in London 1851, Vienna 1873 and London 1876 as an observer for his government; he assisted in geodetic surveys; ... he invented a good many terms [other than topology], some of which have became current: "entropic phenomenona", "nodal points", "homocentric light", "telescopic system", " geoid" ...he coined "one micron" for the millionth of a metre ...*SAU

1927 William Henry Dines (5 Aug 1855, 24 Dec 1927) was an English meteorologist (like his father) and inventor of related measurement instruments such as the Dines pressure tube anemometer (the first instrument to measure both the velocity and direction of wind, 1901), a very lightweight meteorograph, and a radiometer (1920). He joined the Royal Meteorological Society study of the cause of the disastrous Tay Bridge collapse of 1879. His measurements of upper air conditions, first with kites and later by balloon ascents (1907), brought an understanding of cyclones from dynamic processes in the lower stratosphere rather than thermal effects nearer to the ground.*TIS

1962 Wilhelm Friedrich Ackermann (29 March 1896 – 24 December 1962) was a German mathematician best known for the Ackermann function, an important example in the theory of computation.*Wik

1994 Alfred Leon Foster (13 July 1904 in New York City, New York, USA - 24 Dec 1994 in Berkeley, California, USA) Foster went on to define the concept of a primal algebra generalising a Boolean algebra within the theory of varieties of universal algebras. In 1953 showed that the variety generated by a primal algebra has the same essential structure as the variety of Boolean algebras. He continued devoting his efforts to the structure theory of algebras that are generalizations of Boolean algebras and, more than ten years down the line in 1966, he published Families of algebras with unique (sub-)direct factorization. Equational characterization of factorization in Mathematische Annalen.*SAU

2000 Laurence Chisholm Young (14 July 1905 – 24 December 2000) was a mathematician known for his contributions to measure theory, the calculus of variations, optimal control theory, and potential theory. He is the son of William Henry Young and Grace Chisholm Young, both prominent mathematicians.
The concept of Young measure is named after him. *Wik

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