Mexico City sinks about 10 inches a year. See more

Men can read smaller print than women; women can hear better. See more

It took approximately 2.5 million blocks to build the Pyramid of Giza, which is one of the Great Pyramids. See more

The average person falls asleep in seven minutes. See more

In 10 minutes, a hurricane releases more energy than all of the world's nuclear weapons combined. See more

If you yelled for 8 years, 7 months and 6 days, you would have produced enough sound energy to heat one cup of coffee. See more

A day on the planet Mercury is twice as long as its year. See more

There are more bacteria in your mouth than the human population of the U.S.A. and Canada combined. See more

The Netherlands has built 800 miles of massive dikes and sea walls to hold back the sea. See more