## Saturday, 16 July 2011

### On This Day in Math - July 16

Pure mathematics is the world's best game.
It is more absorbing than chess, more of a gamble than poker,
and lasts longer than Monopoly.
It's free. It can be played anywhere
- Archimedes did it in a bathtub.

-Richard J. Trudeau

EVENTS
The 197th day of this year; 197 is the sum of all digits of all two-digit prime numbers: 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.  It is simple to show that the sum of one-digit primes is 17.  Do the sum of the digits of n-digit primes always end in seven?
197 is the smallest prime number that is the sum of 7 consecutive primes: 17 + 19 + 23 + 29 + 31 + 37 + 41 (student challenge: can there be a prime that is the sum of eight consecutive primes?)

197 is the sum of the first twelve prime numbers: 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37
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433 B.C. The Metonic 19-year cycle of the moon enacted. This masterpiece of approximation (19 solar years = 235 lunations) is still used today in the computation of the date of Easter. [See A. Philip, The Calendar: Its History, Structure and Improvement, p. 8]*VFR  (I have also seen June 27, 432 BC given for this event.  Purist may choose up sides and argue for their choice)

1661 Europe’s earliest modern-style banknotes, available to all and sundry with each note worth a fixed sum, were introduced by the Bank of Stockholm. The bank had been started in 1657 by Johan Palmstruch in close collaboration with the royal government which pocketed half the profits. It was Palmstruch who suggested the kreditivsedlar (credit notes) and they provided a welcome alternative to Sweden’s massive copper coins, which were dismayingly heavy and clumsy. Colloquially known as Palmstruchers the notes were printed on thick, white watermarked paper with the word banco as the watermark and carried the date, the bank’s seal and eight signatures, headed by Palmstruch’s, as an assurance of reliability. They were in stated denominations and payable to the bearer and anybody who had one was promised payment by the bank.  (*History Today )

1669  Wallis writes to Oldenburg complaining about the public perception of the Royal Society after Doctor Robert Smith's dedication of the New Theater consisted of only, "Satyrical invectives against Cromwell, Fanaticks, the Royal Society and Philosophy." *The mathematical work of John Wallis, D.D., F.R.S., (1616-1703) By Joseph Frederick Scott, pg 11

1730 The famous lines of Alexander Pope (1688–1744) which were intended as an epitaph for Newton:
Nature and Nature’s Laws lay hid in night: God said, Let Newton be! and all was light.
were published in the Grub-Street Journal, the ﬁrst time they appeared in print. *VFR

1828 James Ryan recorded his copyright for The Diﬀerential and Integral Calculus, the ﬁrst calculus book written by a U.S. citizen.*VFR

1848 Exactly 50 years earlier, Gauss received his doctorate. As part of the show at the golden jubilee Gauss was to light his pipe with a manuscript page from his Disquisitiones Arithmeticae. His student Dirichlet was outraged by this sacrilege and boldly snatched the paper as a treasured memento. [Eves, History of Mathematics, p. 370]*VFR

1945 The ﬁrst atomic bomb explosion was carried out in a test at Alamogordo Air Base in New Mexico, at 12:29:15 G.C.T.  *VFR The atomic bomb was invented by two refugee German scientists in Britain, Professor Rudolph Peierls and Otto Frisch, of Birmingham University. They designed a "blue-print" for making an atom bomb in 1940. It actually began when the Italian-born physicist Enrico Fermi, working in the United States, invented an apparatus which produced the first atomic chain reactions. In 1940 both the Americans and British were researching the atom bomb and when the United States entered WW2, the British joined the American "Manhattan Project" and production of the bomb went on ahead in the US.*TIS

In 1994, the first of 21 asteroids, major fragments of the comet Shoemaker-Levy 9 broken-up 2 years earlier, hit Jupiter, creating a 1200-mile wide fireball 600 miles high to the joy of astronomers awaiting the celestial fireworks, giving scientists their first chance to observe such a collision as it happened, and others through July 22. Jupiter is a gas giant, made up mostly of hydrogen and helium in gas and liquid form.When we observe Jupiter, we are looking not at a solid surface, but a banded atmosphere with swirling clouds and huge storms.*TIS

BIRTHS
1678 Jakob Hermann was a Swiss mathematician who made contributions to dynamics.*SAU

1746 Giuseppe Piazzi Italian astronomer and author, born in Valtellina, discovered the first asteroid - Ceres. He established an observatory at Palermo and mapped the positions of 7,646 stars. He also discovered that the star 61 Cygni had a large Proper Motion, which led Bessel to chose it as the object of his parallax studies. He discovered Ceres on 1 Jan 1801, but was able to make only three observations. The term "asteroid," meaning "star-like" was coined (1803) by Herschel. Fortuitously, Gauss had recently developed mathematical techniques that allowed the orbit to be calculated. Within the next few years, astronomers discovered three more asteroids: Pallas, Juno, and Vesta. The thousandth Asteroid discovered was named Piazzi in his honor.*TIS

1819 Siegfried Heinrich Aronhold (16 July 1819 Angerburg, East Prussia – 13 March 1884, Berlin, Germany) was a German mathematician who worked on invariant theory and introduced the symbolic method.*Wik
1902 Gheorghe Calugareanu As a lecturer, Calugareanu gave simple, clear explanations. He spoke quietly and he would start every lecture by spending ten minutes going over the material from the previous lecture. At the end of the lecture he would explain what was coming in the next lecture. This makes it sound as if he would make little progress, but on the contrary, he was able to go steadily though the material. Students really understood the lectures as he gave them and his lectures were models for the highest quality of teaching. His research was elegant and his personality shone through his mathematical papers as it did in his teaching. Some of his results had applications in molecular biology or fluid mechanics. In fact Calugareanu spoke of about the tension between pure and applied mathematics in his autobiographical paper . He remarks there that, in Communist Romania, the party and the state stress the importance of research which leads to improvements in the conditions of life. However, they also recognize the importance of fundamental research as a foundation for and preliminary to applications. The paper allows us to glimpse other aspects of Calugareanu's approach to mathematics. He addresses younger mathematicians explaining that because of the rapid expansion in mathematics there is great importance in having a guiding thread or theme in one's research. This, he explains, is especially true if one's work spans several fields. His own work did indeed span several fields, and he recognises that his thread was the idea of invariance which ran through his work in complex variables, differential topology, and modern algebra.*SAU

1903 Irmgard Flugge-Lotz (6 July 1903 - 22 May 1974)born in Hameln, Germany. Her father encouraged her in mathematics, but she chose engineering because “I wanted a life which would never be boring—a life in which new things would always occur.” She studied applied mathematics at the Technical University of Hanover and in 1929 she became a Doktor-Ingenieur, the equivalent of an American Ph.D. in Engineering. She made contributions to aerodynamics, control theory, and ﬂuid mechanics. In 1960 she became full professor at Stanford. *WM
1918  S. H. Aronhold. He made important contributions to the theory of invariants.*Wik

1951 Dan Bricklin American computer scientist who with Bob Frankston created VisiCalc, the first spreadsheet computer program (1979) which created a market beyond hobbyists for the emerging personal computers. Businesses found the program very useful because of the speed and accuracy of its calculations. Originally written in 6502 assembly language to run on a 32K-byte Apple II, it was soon ported to virtually all major 6502- and Z80-based personal computers then available. They did not reap huge financial profits from the spreadsheet program, despite eventually selling over a half-million copies by 1983, because at the time, copyright protection was not generally sought for software, and it was subsequently surpassed by Lotus 1-2-3 *TIS

DEATHS
1739 Charles François de Cisternay Du Fay was a French chemist who made early experiments in electricity. In 1733, he distinguished electrical fluid in two types he named "vitreous electricity" and "resinous electricity" depending on the objects that produced the charge (subsequently called "positive" and "negative" by Benjamin Franklin). Du Fay discovered that objects with like charges repel each other, but oppositely charged objects repel. He also noted the effect of electricity shock on his body, and visible spark when making contact with a highly charged object. He observed that electricity may be conducted in the gaseous matter (now called plasma) adjacent to a red-hot body. Du Fay was also a pioneer in crystal optics.*TIS

1981 Jacob Wolfowitz (March 19, 1910 – July 16, 1981) was a Polish-born American statistician and Shannon Award-winning information theorist. He was the father of former Deputy Secretary of Defense and World Bank Group President Paul Wolfowitz.
While a part-time graduate student, Wolfowitz met Abraham Wald, with whom he collaborated in numerous joint papers in the field of mathematical statistics. This collaboration continued until Wald's death in an airplane crash in 1950. In 1951, Wolfowitz became a professor of mathematics at Cornell University, where he stayed until 1970. He died of a heart attack in Tampa, Florida, where he was a professor at the University of South Florida.
Wolfowitz's main contributions were in the fields of statistical decision theory, non-parametric statistics, sequential analysis, and information theory.*Wik
1994 Julian Seymour Schwinger American physicist who shared the 1965 Nobel Prize in Physics for his contributions to quantum electrodynamics (with Richard Feynman and Shin-Itiro Tomonaga). Schwinger worked on reconciling quantum mechanics with Albert Einstein's special theory of relativity. He published his first physics paper at the age of sixteen. During WW II, he developed important methods in electromagnetic field theory, which advanced the theory of wave guides. His variational techniques were applied in several fields of mathematical physics. In the 1940's he was one of the inventors of the "renormalization" technique. In 1957, he proposed that theoretically there were two different neutrinos: one associated with the electron and one with the muon. Later experimental work provided verification. He invented source theory. *TIS  Schwinger was Oppenheimer's most brilliant student. Oppenheimer once said of him, "When ordinary people give a talk, they tell you how to do it.  When Julian gives a talk, it is to tell you that only he can do it."  *Freeman Dyson, Infinities in all Directions.

Credits:
*WM = Women of Mathematics. Grinstein & Campbell.
*VFR = V Frederick Rickey, USMA
*TIS= Today in Science History
*Wik = Wikipedia
*SAU=St Andrews Univ. Math History