The word "unfriend" appeared in print all the way back in 1659.
Stephanie Kwolik's name might not ring a bell, but she's responsible for saving thousands of lives. In 1965, she invented Kevlar, the material used in bulletproof vests.
Pigs are no longer commonly employed to rustle up truffles; specially-trained dogs (who are equally adept at the job) have now taken their place.
The M.C. in M.C. Escher stands for Maurits Cornelis.
The genetic mutation that causes red hair also causes redheads to be more resistant to anesthesia. They can require up to 25% more than patients of other hair colors.
Only one U.S. coin — the zinc-coated steel penny produced during World War II — can be picked up by a magnet.
The phrase "Mr. Mojo Risin'," repeated by Jim Morrison in the Doors' song "L.A. Woman," is an anagram of the vocalist's name.