Hobo college
James Eads How, known as the Millionaire Hobo, founded a series of “colleges” to house, feed, and educate the hobos of America.
One electron in the universe
A positron can be modelled like an electron that is travelling backwards in time. John Wheeler proposed that this could mean all electrons and positrons in the universe could in fact be the same particle, just bouncing back and forth across time.
Walking on water
Non-Newtonian fluids are usually liquid, but when force is applied they can change to be more solid or more liquid. Oobleck (a mixture of cornstarch and water) behaves like a liquid, but you can walk over it as if you were walking on water.