## Mathematicians Of The Day

### 28th September

On this day in 1695, after fitting several comets data using Newton's proposal that they followed parabolic paths, Edmund Halley tested his own measurements of the 1682 comet against an elliptical orbit. He wrote to Newton,

I am more and more confirmed that we have seen that Comet now three times since the year 1531.The postage stamp of one of today's mathematicians at THIS LINK was issued in 1986.

Click on Ⓟ for a poster.

##### Born:

- 1605: Ismael Boulliau Ⓟ
- 1698: Pierre-Louis Moreau de Maupertuis Ⓟ
- 1761: François Budan
- 1824: George Allman Ⓟ
- 1833: Henri Delannoy Ⓟ
- 1873: Julian Coolidge Ⓟ
- 1881: Edward Ross
- 1893: Hilda Geiringer Ⓟ
- 1901: Kurt Friedrichs Ⓟ
- 1925: Martin Kruskal Ⓟ
- 1938: Hideo Tanaka Ⓟ

##### Died:

- 1667: Jacob Gool Ⓟ
- 1694: Gabriel Mouton Ⓟ
- 1869: Guglielmo Libri Ⓟ
- 1928: Pierre Puiseux Ⓟ
- 1949: Karl Sundman Ⓟ
- 1953: Edwin Hubble Ⓟ
- 1967: Stanisław Knapowski Ⓟ
- 1992: John Leech Ⓟ
- 1998: Anzelm Iwanik Ⓟ
- 2004: Jack van Lint Ⓟ

#### Quotation of the day

##### From Julian Coolidge

[Upon proving that the best betting strategy for "Gambler's Ruin" was to bet all on the first trial.]

It is true that a man who does this is a fool. I have only proved that a man who does anything else is an even bigger fool.