The etymology of the term 'piggyback' goes back to the 1500s, when it had nothing to do with pigs. Learn more in this episode of BrainStuff, based on this article: https://people.howstuffworks.com/piggyback-ride.htm

What Pranks Have Astronauts Pulled?
08:40

How Can Your Body Learn to Tolerate Cold?
10:58

How Did the War of 1812 Settle the American Revolution?
10:23