Template:Are You Sure/October 4

• ... that theoretical physicist Max Planck (23 April 1858 – 4 October 1947) lost much of his will to live after his son Erwin was arrested by and died at the hands of the Gestapo?

• ... that mathematician and actuary Harald Cramér became interested in the field of probability before it was accepted branch of mathematics, and in a 1926 paper in 1926 Cramér wrote: "The probability concept should be introduced by a purely mathematical definition, from which its fundamental properties and the classical theorems are deduced by purely mathematical operations."?