## Mathematicians Of The Day

### 8th November

On this day in 1824, Gauss wrote to Franz Taurinus

The postage stamp of one of today's mathematicians at THIS LINK was issued in 1986.

The assumption that the sum of the three angles of a triangle is less than 180° leads to a curious geometry, quite different from ours [i.e. Euclidean geometry] but thoroughly consistent, which I have developed to my entire satisfaction, so that I can solve every problem in it excepting the determination of a constant, which cannot be fixed a priori. .... the three angles of a triangle become as small as one wishes, if only the sides are taken large enough, yet the area of the triangle can never exceed, or even attain a certain limit, regardless of how great the sides are.On this day in 2011 Google released a Halley doodle.

The postage stamp of one of today's mathematicians at THIS LINK was issued in 1986.

Click on Ⓟ for a poster.

##### Born:

- 1656: Edmond Halley Ⓟ
- 1843: Moritz Pasch Ⓟ
- 1846: Eugenio Bertini Ⓟ
- 1848: Gottlob Frege Ⓟ
- 1854: Johannes Robert Rydberg Ⓟ
- 1868: Felix Hausdorff Ⓟ
- 1904: William Edge Ⓟ
- 1912: Elgy Johnson Ⓟ
- 1914: George Dantzig Ⓟ
- 1919: Leopold Schmetterer Ⓟ

##### Died:

- 1633: Xu Guang-qi Ⓟ
- 1719: Michel Rolle
- 1832: Amélie Harlay Ⓟ
- 1858: George Peacock Ⓟ
- 1940: Andrei Petrovich Kiselev Ⓟ
- 1952: Gino Fano Ⓟ
- 1992: Tatsujiro Shimizu Ⓟ
- 2001: Albrecht Fröhlich Ⓟ

#### Quotation of the day

##### From Gottlob Frege

Every good mathematician is at least half a philosopher, and every good philosopher is at least half a mathematician.