## Mathematicians Of The Day

### 13th April

Click on Ⓟ for a poster.

##### Born:

- 953: al-Karaji Ⓟ
- 1728: Paolo Frisi Ⓟ
- 1813: Duncan Gregory Ⓟ
- 1823: Oscar Schlömilch Ⓟ
- 1850: Arthur Downing Ⓟ
- 1869: Isabel Maddison Ⓟ
- 1879: Francesco Severi Ⓟ
- 1909: Stan Ulam Ⓟ

##### Died:

- 1728: Samuel Molyneux
- 1890: Andrew Hart Ⓟ
- 1906: Raphael Weldon Ⓟ
- 1941: Annie Jump Cannon Ⓟ
- 2004: David Fowler Ⓟ
- 2014: Emma Castelnuovo Ⓟ

#### Quotation of the day

##### From Stan Ulam

To exist (in mathematics), said Henri Poincaré, is to be free from contradiction. But mere existence does not guarantee survival. To survive in mathematics requires a kind of vitality that cannot be described in purely logical terms.