## Mathematicians Of The Day

### 20th October

On this day in 1939 the three Polish mathematicians Rejewski, Rozycki and Zygalski began decoding German Enigma cipher messages from a station near Paris. World War II had begun about two weeks earlier.

On this day in 2014 Google released a Wren doodle.

On this day in 2014 Google released a Wren doodle.

Click on Ⓟ for a poster.

##### Born:

- 1632: Christopher Wren Ⓟ
- 1827: Charles Merrifield Ⓟ
- 1863: William Young Ⓟ
- 1865: Aleksandr P Kotelnikov Ⓟ
- 1881: George Waddel Snedecor Ⓟ
- 1893: Xiong Qinglai Ⓟ
- 1904: Hans Lewy Ⓟ
- 1914: R H Bing Ⓟ

##### Died:

- 1896: Félix Tisserand Ⓟ
- 1972: Harlow Shapley Ⓟ
- 1974: Harold Ruse Ⓟ
- 1984: Paul Dirac Ⓟ
- 1987: Andrey Kolmogorov Ⓟ
- 2014: Gilbert Baumslag Ⓟ

#### Quotation of the day

##### From Paul Dirac

I learned to distrust all physical concepts as the basis for a theory. Instead one should put one's trust in a mathematical scheme, even if the scheme does not appear at first sight to be connected with physics. One should concentrate on getting interesting mathematics.