## Thursday, 5 July 2018

### On This Day in Math - July 5

There is no smallest among the small and no largest among the large,
But always something still smaller and something still larger.

Quoted in E Maor, To Infinity and Beyond: a Cultural History of the Infinite

The 186th day of the year;  186 is the product of the first four primes less; the product of the first four positive integers (7 x 5 x 3 x 2 - 4 x 3 x 2 x 1 = 186) . *Prime Curios

186 is the sum of consecutive primes, 186 = = 89 + 97,

186 is a sphenic (wedge) number, product of 3 distinct primes: 186 = 2*3*31

and from Jim Wilder @wilderlab An equation for July 4th: 7⁴ = 2401 = (2 + 4 + 0 + 1)⁴   And a followup from World Observer@WKryst2011 points out that there are only two other such year dates. (student's should find both)

EVENTS
In 1643, an exceptionally strong wind occurred in Essex County, Mass. The description by Governor John Winthrop is the first record suggestive of a tornado in the U.S.: "There arose a sudden gust so violent for one-half hour as it blew down multitudes of trees. It lifted up their meeting house at Newbury, the people being in it. It darkened the air with dust, yet through God’s great mercy it did no hurt, but only killed one Indian with the fall of a tree." However, no tornado-like funnel shape - so likely to be noted, if seen - was not included in his log. So, it was likely not a tornado, in fact, but a severe straight-line squall with strong downburst winds. Reverend Increase Mather cited a likely tornado in Jul 1680 storm at Cambridge, Mass*TIS

1687 Halley wrote to Newton that his Principia was ﬁnally published. [Westfall, p. 468] *VFR 1687 – ushering in a tidal wave of changes in thought that would significantly accelerate the already ongoing scientific revolution by giving it tools that produced technologically valuable results, which had theretofore been otherwise unobtainable. (Thony Christie has pointed out that the use of "published" may give a false impression to the modern reader, even though this is the date printed on the title page of the document. The actual words, used by Halley were, "I have at length brought your Book to an end, and hope it will please you. the last errata came just in time to be inserted. I will present from you the books you desire to...." )

1698 Johann Bernoulli, in a letter to Leibniz, deﬁned the notion of a function. The term “function” is due to Leibniz. [Cajori, Historical Introduction to the Mathematical Literature, p. 96]*VFR

1766 Ben Franklin writes from England to Rev Ezra Stiles, "I have lately propos’d our ingenious and learned Contriman Mr: Winthorp, as a Member of the Royal Society." On Feb 20, 1766. John Winthrop Esqr. Hollisian Professor of Mathematics and Natural Philosophy was unanimously elected Fellow of the Royal Society in London. *Franklin Papers, Natl Archives

1951 – William Shockley invents the junction transistor. *Wik

2012  Gresham College  announces the appointment of Raymond Flood, Fellow of Kellogg College, Oxford, as Professor of Geometry and Other Mathematical Sciences. The Geometry chair at Gresham College is the oldest in England, dating back to the College’s founding in 1597. Gresham College was the first higher education institution in England besides the Universities of Oxford and Cambridge, and it was created with the guiding principle of providing free education to the traders and people of London so that England could maintain a position at the forefront of a global economy. Gresham College’s central position in science and mathematics has seen the Royal Society formed within the College, and past luminaries including Henry Briggs, Sir Christopher Wren, Robert Hooke, Sir Christopher Zeeman and Sir Roger Penrose. *Gresham Press Release

BIRTHS
1820 William John Macquorn Rankine, (5 July 1820 – 24 December 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 While many students never encounter it, there is a temperature scale named after Rankine. It is the Fahrenheit scale equivalent of the Kelvin scale for Celsius.

1867 Andrew Ellicott Douglass (July 5, 1867, Windsor, Vermont – March 20, 1962, Tucson, Arizona) American astronomer and archaeologist who coined the name dendrochronology for tree-ring dating, a field he originated while working at the Lowell Observatory, Flagstaff, Ariz. (1894-1901). He showed how tree rings could be used to date and interpret past events. Douglass also sought a connection between sunspot activity and the terrestrial climate and vegetation. The width of tree rings is a record of the rainfall, with implications on the local food supply in dry years. Archaeologist Clark Wissler collaborated in this work by furnishing sections of wooden beams from Aztec Ruin and Pueblo Bonito so Douglass could cross-date the famous sites. Thus the study of tree rings enables archaeologists to date prehistoric remains. *TIS

1888 Louise Freeland Jenkins (July 5, 1888 – May 9, 1970) was an American astronomer.
She was born in Fitchburg, Massachusetts. In 1911 she graduated from Mount Holyoke College, then she received a Master's degree in astronomy in 1917 from the same institution. From 1913 to 1915 she worked at the Allegheny Observatory in Pittsburgh.
About 1921 she moved to Japan, becoming a teacher at the Women's Christian College, a missionary school. She returned to the United States in 1925 after her father died. A year later she returned to teach at a school in Himeji. (Hinomoto Gakuen girl's high school.)
In 1932 she returned to the US and became a staff member at Yale University Observatory. She was co-editor of the Astronomical Journal starting in 1942, and continued in this post until 1958. She would return to visit Japan later in her life.
She was noted for her research into the trigonometric parallax of nearby stars. She also studied variable stars.
The crater Jenkins on the Moon is named in her honor. *Today in Astronomy

1946 Gerardus (Gerard) 't Hooft (July 5, 1946 - ) is a Dutch theoretical physicist and professor at Utrecht University, the Netherlands. He shared the 1999 Nobel Prize in Physics with his thesis advisor Martinus J. G. Veltman "for elucidating the quantum structure of electroweak interactions".
His work concentrates on gauge theory, black holes, quantum gravity and fundamental aspects of quantum mechanics. His contributions to physics include a proof that gauge theories are renormalizable, dimensional regularization, and the holographic principle. *Wik

DEATHS
1865 Oskar Bolza died (12 May 1857–5 July 1942). Bolza was a German mathematician, and student of Felix Klein. He was born in Bad Bergzabern, Bolza published The elliptic s-functions considered as a special case of the hyperelliptic s-functions in 1900 which related to work he had been studying for his doctorate under Klein. However, he worked on the calculus of variations from 1901. Papers which appeared in the Transactions of the American Mathematical Society over the next few years were: New proof of a theorem of Osgood's in the calculus of variations (1901); Proof of the sufficiency of Jacobi's condition for a permanent sign of the second variation in the so-called isoperimetric problems (1902); Weierstrass' theorem and Kneser's theorem on transversals for the most general case of an extremum of a simple definite integral (1906); and Existence proof for a field of extremals tangent to a given curve (1907). His text Lectures on the Calculus of Variations published by the University of Chicago Press in 1904,[3] became a classic in its field and was republished in 1961 and 2005.[4] After the death of his friend Maschke in 1908, Bolza became unhappy in the United States and, in 1910, he and his wife returned to Freiburg in Germany where he was appointed as an honorary professor. Chicago gave him the title of 'non-resident professor of mathematics' which he retained for the rest of his life.*Wik He returned to Germany in 1910, where he researched function theory, integral equations and the calculus of variations. In 1913, he published a paper presenting a new type of variational problem now called "the problem of Bolza." The next year, he wrote about variations for an integral problem involving inequalities, which later become important in control theory. Bolza ceased his mathematical research work at the outbreak of WW I in 1914.*TIS

1911 George Johnstone Stoney (15 February 1826 – 5 July 1911) Irish physicist who introduced the term electron for the fundamental unit of electricity. At the Belfast meeting of the British Association in Aug 1874, in a paper: On the Physical Units of Nature, Stoney called attention to a minimum quantity of electricity. He wrote, "I shall express 'Faraday's Law' in the following terms ... For each chemical bond which is ruptured within an electrolyte a certain quantity of electricity traverses the electrolyte which is the same in all cases." Stoney offered the name electron for this minimum electric charge. When J.J. Thomson identified cathode rays as streams of negative particles, each carrying probably Stoney's minimum quantity of charge, the name was applied to the particle rather than the quantity of charge.*TIS

1926 Peter Scott Lang graduated from Edinburgh University and after a period as assistant in Edinburgh he became Regius Professor of Mathematics at St Andrews. He held this position for 42 years. *SAU

1932 Rene Louis Baire died (21 January 1874 – 5 July 1932) a French mathematician most famous for his Baire category theorem, which helped to generalize and prove future theorems. His theory was published originally in his dissertation Sur les fonctions de variable réelles ("On the Functions of Real Variables") in 1899.*Wik French mathematician whose study of irrational numbers and whose concept to divide the notion of continuity into upper and lower semi-continuity greatly influenced the French School of Mathematics. His doctoral thesis led to the solution of the problem of the characteristic property of limited functions of continuous functions and helped establish the theory of functions of real variables.*TIS

1977 Henry Scheffé (New York City, USA, 11 April 1907 – Berkeley, California, USA, 5 July 1977) worked in several different areas of Statistics, including linear models, analysis of variance and nonparametrics.*SAU He is known for the Lehmann–Scheffé theorem and Scheffé's method.

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