Isaac Newton · every age

What was Isaac Newton doing at 56?

Invented calculus and gravity theory in a plague year at 23

1. c. 1699

   Master of the Mint at 56, a post he kept for life

   He also showed the Royal Society an improved reflecting octant.

   Source: en.wikipedia.org

Portrait: Portrait: Godfrey Kneller (1689), public domain, via Wikimedia Commons · source