## Mathematicians Of The Day

### 22nd July

On this day in 1680, Ehrenfried Walter von Tschirnhaus was elected to the Paris Académie des Sciences.

Click on Ⓟ for a poster.

##### Born:

- 1755: Gaspard de Prony Ⓟ
- 1784: Wilhelm Bessel Ⓟ
- 1795: Gabriel Lamé Ⓟ
- 1861: Ernst Fiedler Ⓟ
- 1872: Alexander Durie Russell Ⓟ
- 1882: Konrad Knopp Ⓟ
- 1887: Gustav Hertz Ⓟ
- 1902: Reinhold Baer Ⓟ
- 1904: Donald Eperson Ⓟ
- 1907: Edgar Raymond Lorch Ⓟ
- 1926: John Aitchison Ⓟ
- 1930: Shreeram Shankar Abhyankar Ⓟ
- 1935: John Stallings Ⓟ
- 1948: Chandra Kintala Ⓟ

##### Died:

- 1575: Francesco Maurolico Ⓟ
- 1826: Giuseppe Piazzi Ⓟ
- 1943: William Osgood Ⓟ
- 1950: Vyacheslaw Vassilievich Stepanov Ⓟ
- 1959: David van Dantzig Ⓟ
- 1995: Otakar Boruvka Ⓟ

#### Quotation of the day

##### From David van Dantzig

Neither in the subjective nor in the objective world can we find a criterion for the reality of the number concept, because the first contains no such concept, and the second contains nothing that is free from the concept. How then can we arrive at a criterion? Not by evidence, for the dice of evidence are loaded. Not by logic, for logic has no existence independent of mathematics: it is only one phase of this multiplied necessity that we call mathematics.

How then shall mathematical concepts be judged? They shall not be judged. Mathematics is the supreme arbiter. From its decisions there is no appeal.We cannot change the rules of the game, we cannot ascertain whether the game is fair. We can only study the player at his game; not, however, with the detached attitude of a bystander, for we are watching our own minds at play.