RIP Tom Apostol (1923–2016)

Caltech lost a legend today: Tom Apostol has died.

Here I quote from Kevin Hickerson's Facebook post (whence I got the news): Our department lost a great one today. Tom M. Apostol, emeritus professor of Mathematics, is well known among math and science students the world over, including 100% of all Caltech alums, for his mathematically rigorous and technically unmatched textbooks on Calculus, affectionately known as "Tommy I" and "Tommy II" (1923-2016) RIP

I never did take a class with Apostol, as he retired from teaching classes just before I got to Tech. I skipped Math 1, so I only ended up using Tommy II as a textbook.

Update (5/10/16): Caltech has posted an obituary.