## Mathematicians Of The Day

### 23rd September

##### Born:

- 1768: William Wallace (poster)
- 1791: Johann Franz Encke (poster)
- 1819: Hippolyte Fizeau (poster)
- 1851: Ellen Hayes (poster)
- 1852: Walter GrĂ¶bli (poster)
- 1900: David van Dantzig (poster)
- 1910: Lamberto Cesari (poster)
- 1968: Wendelin Werner

##### Died:

- 1657: Joachim Jungius (poster)
- 1877: Urbain Le Verrier (poster)
- 1919: Heinrich Bruns (poster)
- 1938: Maurice d'Ocagne (poster)
- 1971: James Alexander (poster)
- 1982: Bella Abramovna Subbotovskaya
- 1984: Gheorghe Pic (poster)

#### Quotation of the day

##### From David van Dantzig

The attempt to apply rational arithmetic to a problem in geometry resulted in the first crisis in the history of mathematics. The two relatively simple problems -- the determination of the diagonal of a square and that of the circumference of a circle -- revealed the existence of new mathematical beings for which no place could be found within the rational domain.

Theorem of the day from Robin Whitty