Caesar's Last Breath
How many molecules from Caesar’s last breath do we inhale with each breath we take? Shockingly, the answer is about one molecule—we actually do share breaths with Caesar! And, by extension, every breath we take is composed of the previous breaths of everyone who ever lived —Socrates, Lincoln, Einstein, etc. Isn’t that crazy? This is a classic exercise in Fermi estimation —it even has a book named…