**Mathematicians are like Frenchmen:**

whatever you say to them

they translate into their own language

and forthwith it is something entirely different.

whatever you say to them

they translate into their own language

and forthwith it is something entirely different.

The 140th day of the year; 140 is the sum of the squares of the first seven positive integers. 1

^{2}+ 2

^{2}+ 3

^{2}+ 4

^{2}+ 5

^{2}+ 6

^{2}+ 7

^{2}= 140. *Prime Curios

140 is character limit on Twitter

**EVENTS**

1570 Cartographer Abraham Ortelius issues Theatrum Orbis Terrarum, the first modern atlas. *RMAT

1663 Robert Hooke was one of 98 persons who were declared members at a meeting of the Royal Society. He was admitted to society on 3 Jun 1663, and was peculiarly exempted of all payments. Before the Royal Society had been establish in 1660, Hooke was already distinguished for the invention of various astronomical instruments, and the air-pump he contrived for Charles Boyle (whom he had assisted for several years with chemical experiments at the Philosophical Society, Oxford). He invented a balance or pendulum spring (1656-58), one of the greatest improvements in the construction of timepieces. By 1662, he had been appointed curator of experiments to the Royal Society, and on 11 Jan 1664, awarded a salary of £30 per annum for life for that position.*TIS

**1665**Newton's earliest use of dots, "pricked letters," to indicate velocities or fluxions is found on a leaf dated May 20, 1665; no facsimile reproduction of it has ever been made.' The earliest printed account of Newton's fluxional notation appeared from his pen in the Latin edition of Wallis' Algebra [Cajori, History of Mathematical Notations, vol. 2, p. 197] *VFR

1716 In a letter written to Leibniz, May 20, 1716, John Bernoulli discussed the equation:d

^{2}y/dx

^{2}= 2y/x

^{2}

where the general solution when written in the form

y = x

^{2}/a + b

^{2}/3x

involves three cases: When b approaches zero the curves are parabolas; when a approaches infinity, they are hyperbolas; otherwise, they are of the third order. *John E. Sasser, HISTORY OF ORDINARY DIFFERENTIAL EQUATIONS THE FIRST HUNDRED YEARS

1875 The International Bureau of Weights and Measures established by the International Metric Convention, Sevres, France. The bureau is the repository for the “International Prototype Meter” and the “International Prototype Kilogram.” *SAU= St. Andrews Univ

And for your (in case you thought that 3D movie technology was new, file)

**In 1901**, Claude Grivolas, one of Pathe's main shareholders in Paris, France, invented a projector that produced three-dimensional pictures.*TIS

**1927**At 7:40 a.m., Charles Lindbergh took off from Roosevelt Field in Long Island, N.Y., aboard the "Spirit of St. Louis" monoplane on his historic first solo flight across the Atlantic Ocean. He arrived in France thirty-three and one-half hours later. *TIS

1930 The Institute for Advanced Study incorporated. Two and a half years later Albert Einstein and Oswald Veblen were appointed the ﬁrst professors. [Goldstein, The Computer from Pascal to von Neumann, p. 77]*VFR

**In 1956,**the first hydrogen fusion bomb (H-bomb) to be dropped from an airplane exploded over Namu Atoll at the northwest edge of the Bikini Atoll. The fireball was four miles in diameter. It was designated as "Cherokee," as part of "Operation Redwing."*TIS

1961 France issued a stamp honoring Charles Coulomb (1736–1806) [Scott #B 352].

1968 A team of six high school students from Upstate New York went to London to participate in the Fourth British Mathematical Olympiad. This was the ﬁrst time a team from the U.S. participated in an international mathematical competition. [The College Mathematics Journal, 16 (1985), p. 331] *VFR

In 1975 Norway issued a stamp for the centenary of the International Meter Convention in Paris. It pictures Ole Jacob Broch (1818– 1889), the ﬁrst director of the International Bureau of Weights and Measures. [Scott #655] *VFR At least ten other countries issued stamps to commemorate the same event, including Bulgaria, Romania, France, the Soviet Union..... but not the USA. (see 1975 below for another)

1975 Sweden issued a stamp picturing a metric tape measure to honor the centenary of the International Meter Convention in Paris. [Scott #1121] *VFR

In 1990, the Hubble Space Telescope sent its first photograph from space, an image of a double star 1,260 light years away. *TIS

**2012 Solar Eclipse,**A total of 154 U.S. national parks will provide views of the eclipse, from partial to full annularity. Many western parks will offer solar observing as a ranger-led program or host a solar party with the help of local amateur astronomy clubs.

Poster advertising viewing the eclipse from Glen Canyon National Recreation Area. Poster © Tyler Nordgren.

**2063**99 year old Johnny Depp rolls down red-carpet in wheel-chair for opening of Pirates of the Caribbean sequel #42, “Sun City Pirates”.

**1825 George Phillips Bond**((May 20, 1825

*{sometimes given 1826}*– February 17, 1865) Astronomer who made the first photograph of a double star, discovered a number of comets, and with his father discovered Hyperion, the eight moon of Saturn.*TIS

**1861 Henry Seely White**(May 20, 1861 - May 20, 1943) worked on invariant theory, the geometry of curves and surfaces, algebraic curves and twisted curves. *SAU He matriculated at Wesleyan University in Connecticut and graduated with honors in 1882 at the age of twenty-one. White excelled at Wesleyan in astronomy, ethics, Latin, logic, mathematics, and philosophy. At the university, John Monroe Van Vleck taught White mathematics and astronomy. Later, Van Vleck persuaded White to continue to study mathematics at the graduate level.[1] Subsequently, White studied at the University of Göttingen under Klein, and received his doctorate in 1891.

White was Mathematics Department Chair at Northwestern University. He left Northwestern to be near his ill mother and became Chairman of the Mathematics Department at Vassar College. He "attributed his interest in geometry both to his work at Wesleyan and Goettingen and to summers spent working on his grandfather’s farm."[2] His particular interests were in the fields of the geometry of curves and surfaces (Curves, Differential geometry of surfaces), algebraic planes and twisted curves (Algebraic Geometry, Algebraic curves, Twisted curves), homeomorphic sets of lines in a plane (line coordinates), the theory of invariants, relativity in mechanics, and correspondences.

In 1915 Seely was elected a Fellow of the United States National Academy of Sciences. Northwestern conferred upon him an LL.D. in the same year. At the time of its 100th anniversary in 1932, Wesleyan conferred upon him an D.Sc. *Wik

Died on his birthday in 1943

1874 Friedrich Moritz Hartogs (20 May 1874, Brussels–18 August 1943, Munich) was a German-Jewish mathematician, known for work on set theory and foundational results on several complex variables. *Wik

1901 Machgielis (Max) Euwe (last name is pronounced [ˈøːwə]) (May 20, 1901 – November 26, 1981) was a Dutch chess Grandmaster, mathematician, and author. He was the fifth player to become World Chess Champion (1935–37). Euwe also served as President of FIDE, the World Chess Federation, from 1970 to 1978. *Wik

1901 Hannes Olof Gösta Alfvén (born 30 May 1908 in Norrköping, Sweden; died 2 April 1995 in Djursholm, Sweden) was a Swedish electrical engineer, plasma physicist and winner of the 1970 Nobel Prize in Physics for his work on magnetohydrodynamics (MHD). He described the class of MHD waves now known as Alfvén waves. He was originally trained as an electrical power engineer and later moved to research and teaching in the fields of plasma physics and electrical engineering. Alfvén made many contributions to plasma physics, including theories describing the behavior of aurorae, the Van Allen radiation belts, the effect of magnetic storms on the Earth's magnetic field, the terrestrial magnetosphere, and the dynamics of plasmas in the Milky Way galaxy.*Wik

1913 William Redington Hewlett (20 May 1913; Ann Arbor, Michigan - 12 Jan 2001 at age 87) was an American electrical engineer who co-founded the Hewlett-Packard Company, a leading manufacturer computers, computer printers, and analytic and measuring equipment. In 1939, he formed a partnership known as Hewlett-Packard Company with David Packard, a friend and Stanford classmate. (The order of their names was determined by a coin toss.) HP's first product was an audio oscillator based on a design developed by Hewlett when he was in graduate school. Eight were sold to Walt Disney for Fantasia. Lesser-known early products were: bowling alley foul-line indicator, automatic urinal flusher, weight-loss shock machine. The company began with $538 intial capital, and its first production facility was a small garage in Palo Alto. *TIS

**DEATHS**

**1798 Erland Bring**(19 August 1736 – 20 May 1798) was a Swedish mathemaician who made contributions to the algebraic solution of equations.*SAU

At Lund he wrote eight volumes of mathematical work in the fields of algebra, geometry, analysis and astronomy, including Meletemata quaedam mathematematica circa transformationem aequationum algebraicarum (1786). This work describes Bring's contribution to the algebraic solution of equations. *Wik

**1943 Henry Seely White**, died on his birthday. (see 1861 above)

1947 Philipp Eduard Anton von Lenard (7 Jun 1862 - 20 May 1947 at age 84) was a Hungarian-German physicist who received the 1905 Nobel Prize for Physics for his research on cathode rays. He discovered they could leave a cathode ray tube, penetrate thin metal sheets, and travel a short distance in the air, which would become conducting.. In 1902, he observed that a free electron (as in a cathode ray) must have at least a certain energy to ionize a gas by knocking a bound electron out of an atom. His estimate of the required ionization energy for hydrogen was remarkably accurate. Also in 1902, he showed that the photoelectric effect produces the same electrons found in cathode rays, that the photoelectrons are not merely dislodged from the metal surface but ejected with a certain amount of energy. *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