Russian physicist Igor Tamm won the Nobel Prize in physics in 1958.
During the Russian revolution, he was a physics professor at the University of Odessa in the Ukraine. Food was in short supply, so he made a trip to a nearby village in search of food. While he was in the village, a bunch of anti-communist bandits surrounded the town.
Tamm on the 2000 Russian stamp “Idea of phonons, 1929”
The leader was suspicious of Tamm, who was dressed in city clothes. He demanded to know what Tamm did for a living. He explained that he was a university professor looking for food. “What subject?,” the bandit leader asked. Tamm replied “I teach mathematics.”
“Mathematics?” said the leader. “OK. Then give me an estimate of the error one makes by cutting off a Maclaurin series expansion at the nth term. Do this and you will go free. Fail, and I will shoot you.”
Tamm was not just a little astonished. At gunpoint, he managed to work out the answer. He showed it to the bandit leader, who perused it and then declared “Correct! Go home.” Tamm never discovered the name of the bandit.
From “Calculus makes you live longer”, in “100 essential things you didn’t know you didn’t know”, by John Barrow.