At a public lecture in Pittsburgh in 1934, four hundred lucky students were privy to a lecture by Albert Einstein, in which the great man mathematically derived his famous mass-energy equivalence equation: E=mc2. What you see above is a photo from that lecture, and what is thought to be the only surviving photo that shows Einstein working on that derivation.
The photo was pulled from a halftone newspaper clipping by David Topper and Dwight Vincent of the University of Winnipeg, who discovered it in 2007. Sadly, everything is a bit fuzzy so you can’t really make out the famed equation itself. And even though the original article had a crisp picture of Einstein posing next to one of his blackboards, he’s next to the wrong one.