## Thursday, 9 June 2011

### On This Day in Math - June 9

I've been giving this lecture to first-year classes
for over twenty-five years.
You'd think they would begin to understand it by now.
~ J E Littlewood

EVENTS
1795 a provisional metre bar was constructed in brass by Lenoir. On 1 Aug 1793, the metre had been defined to be 1/10 000 000 of the northern quadrant of the Paris meridian (5 132 430 toises of Paris, from the north pole to the equator). On 7 Apr 1795, the first legal definition of the metre was made by the French National Assembly. A second measure was made along the Dunkirk-Barcelona axis (5 130 740 toises of Paris).

1798 Napoleon’s ﬂeet of 500 ships arrived in Malta, and three days later they captured the place. Monge started ﬁfteen elementary schools and one high school there.*VFR

1905  Albert Einstein published his analysis of Planck's quantum theory and its application to light. His article appeared in Annalen der Physik. Though no experimental work was involved, it was for these insights that Einstein earned his Nobel Prize. *TIS

1934 First Donald Duck Cartoon. Amazinly, the "Donal in Mathland" videos that were popular in the eighties in middle schools are still for sell.

BIRTHS

1812 Johann Gottfried Galle German astronomer who on 23 Sep 1846, was the first to observe the planet Neptune, whose existence had been predicted in the calculations of Leverrier. Leverrier had written to Galle asking him to search for the 'new planet' at a predicted location. Galle was then a member of the staff of the Berlin Observatory and had discovered three comets. In 1838, while assistant to Johann Franz Encke, Galle discovered the dark, inner C ring of Saturn at the time of the maxium ring opening. In 1851, he became professor of astronomy at Breslau and director of the observatory there. In 1872, he proposed the use of asteroids rather than regular planets for determinations of the solar parallax, a suggestion which was successful in an international campaign (1888-89).

1885 John Edensor Littlewood born. Littlewood’s Miscellany (1986) is a delightful little book, for it shows a mathematician having fun.*VFR
He collaborated for many years with G. H. Hardy. Together they devised the first Hardy–Littlewood conjecture, a strong form of the twin prime conjecture, and the second Hardy–Littlewood conjecture.
In a 1947 lecture, the Danish mathematician Harald Bohr said, "To illustrate to what extent Hardy and Littlewood in the course of the years came to be considered as the leaders of recent English mathematical research, I may report what an excellent colleague once jokingly said: 'Nowadays, there are only three really great English mathematicians: Hardy, Littlewood, and Hardy–Littlewood.'"
There is a story (related in the Miscellany) that at a conference Littlewood met a German mathematician who said he was most interested to discover that Littlewood really existed, as he had always assumed that Littlewood was a name used by Hardy for lesser work which he did not want to put out under his own name; Littlewood apparently roared with laughter.[citation needed] There are versions of this story involving both Norbert Wiener and Edmund Landau, who, it is claimed, "so doubted the existence of Littlewood that he made a special trip to Great Britain to see the man with his own eyes"*Wik

1960  Carlo W. J. Beenakker (born ) is a professor at Leiden University and leader of the university's mesoscopic physics group, established in 1992. In 1997, he was awarded the Spinoza Prize, the "Dutch Nobel prize". *Wik

DEATHS
1751 John Machin was an English mathematician and astronomer best known for the formulas he invented for calculating π.*VFR
He was a professor of astronomy at Gresham College, London, and is best known for developing a quickly converging series for Pi in 1706 and using it to compute Pi to 100 decimal places.
Machin's formula is:
$\frac{\pi}{4} = 4 \cot^{-1}5 - \cot^{-1}239$
The benefit of the new formula, a variation on the Gregory/Leibniz series (Pi/4 = arctan 1), was that it had a significantly increased rate of convergence, which made it a much more practical method of calculation.
To compute Pi to 100 decimal places, he combined his formula with the Taylor series expansion for the inverse tangent. (Brook Taylor was Machin's contemporary in Cambridge University.) Machin's formula remained the primary tool of Pi-hunters for centuries (well into the computer era).*Wik

1897 Alvan Graham Clark U.S. astronomer, one of an American family of telescope makers and astronomers who supplied unexcelled lenses to many observatories in the U.S. and Europe during the heyday of the refracting telescope. He began a deep interest in astronomy while still at school, then joined the family firm of Alvan Clark & Sons, makers of astronomical lenses. In 1861, testing a new lens, he looked through it at Sirius and observed faintly beside it, Sirius B, the twin star predicted by Friedrich Bessel in 1844. Carrying on the family business, after the deaths of his father and brother, Clark made the 40" lenses of the Yerkes telescope (still the largest refractor in the world). Their safe delivery was a source of anxiety. He died shortly after their first use.

1969 Harold  Davenport worked on number theory, in particular the geometry of numbers, Diophantine approximation and the analytic theory of numbers. He wrote a number of important textbooks and monographs including The higher arithmetic (1952)*SAU