## Mathematicians Of The Day

### 12th February

On this day in 1826, Nikolai Lobachevsky delivered a paper before the mathematics and physics departments of Kazan University on his "imaginary geometry". This was what is now known as hyperbolic geometry.

See THIS LINK.

See THIS LINK.

Click on Ⓟ for a poster.

##### Born:

- 1856: Arnold Droz-Farny
- 1870: Horatio Carslaw Ⓟ
- 1889: Enrico Bompiani Ⓟ
- 1905: Harold Ruse Ⓟ
- 1908: Jacques Herbrand Ⓟ
- 1914: Hanna Neumann Ⓟ
- 1918: Julian Schwinger Ⓟ
- 1921: Kathleen McNulty Antonelli Ⓟ
- 1929: Aleksei Kostrikin Ⓟ
- 1941: Dennis Sullivan Ⓟ

##### Died:

- 1916: Richard Dedekind Ⓟ
- 1958: Douglas Hartree Ⓟ
- 1960: Oskar Anderson Ⓟ
- 1962: Joseph Pérès Ⓟ
- 1977: Ebenezer Cunningham Ⓟ
- 1980: Einar Carl Hille Ⓟ
- 2001: Herbert Robbins Ⓟ
- 2017: Juan Jorge Schäffer Ⓟ

#### Quotation of the day

##### From Richard Dedekind

Numbers are the free creation of the human mind.