1. 1. It takes seven years to digest gum
  2. 2. The Great Wall of China is the only manmade structure visible from space
  3. 3. Humans use only 10 percent of their brains
  4. 4. Water drains backwards in the Southern Hemisphere due to the Earth’s rotation
  5. 5. A penny dropped from the top of a tall building could kill a pedestrian
  6. 6. Lightning never strikes the same place twice
  7. 7. A falling cat will always land on its feet
  8. 8. Yawning is “contagious”
  9. 9. There is no gravity in space

View the entire list at Live Science