The Plague Years of 1665 and 1666

Saturday, April 25, 2020

In 1666, when Cambridge University had been closed due to the Great Plague, one Isaac Newton retired to Woolsthorpe, and over a period of two years developed theories in optics, gravity and early calculus (“the method of fluxions and fluents…“):

All this was in the two plague years of 1665 & 1666. For in those days I was in the prime of my age for invention & minded Mathematicks & Philosophy more then at any time since … [1]

[1]: Whiteside, D. T. “Newton’s Marvellous Year: 1666 and All That.” Notes and Records of the Royal Society of London 21, no. 1 (1966): 32-41. Accessed April 17, 2020. JSTOR 530816.

[2]: Newton’s Waste Book (MS Add.4004), fols 57r-57v