## Mathematicians Of The Day

### 27th July

On this day in 1837, Lejeune Dirichlet presented his first analytic number theory paper at a meeting of the Berlin Academy of Sciences. He proved the fundamental theorem that bears his name:

The postage stamp of one of today's mathematicians at THIS LINK was issued in 1984.

*Every arithmetical sequence an + b, n = 0, 1, 2, ... of integers, where a and b are relatively prime, contains infinitely many primes.*The postage stamp of one of today's mathematicians at THIS LINK was issued in 1984.

Click on Ⓟ for a poster.

##### Born:

- 1667: Johann Bernoulli Ⓟ
- 1801: George Airy Ⓟ
- 1844: Ágoston Scholtz
- 1848: Loránd Eötvös Ⓟ
- 1849: John Hopkinson Ⓟ
- 1867: Derrick Norman Lehmer Ⓟ
- 1871: Ernst Zermelo Ⓟ
- 1879: David Picken Ⓟ
- 1902: Reuben R McDaniel Ⓟ
- 1921: Jonas Kubilius Ⓟ
- 1930: Ismail Mohamed Ⓟ

##### Died:

- 1759: Pierre-Louis Moreau de Maupertuis Ⓟ
- 1870: Pierre-Joseph-Étienne Finck
- 1931: Jacques Herbrand Ⓟ
- 1987: Jan Mikusiński Ⓟ
- 1999: Aleksandr Aleksandrov Ⓟ
- 2015: J W S Cassels Ⓟ
- 2021: Enrique Planchart Ⓟ

#### Quotation of the day

##### From Johann Bernoulli

I recognise the lion by his claw.

[After reading an anonymous solution to a problem that he realised was Newton's solution.]