In 1999, Harvard physicist Lene Hau was able to slow down light to 17 meters per second and in 2001, was able to stop light completely.
39
Iron weighs more after it rusts.
16
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
The average temperature at 40,000 feet above sea level is -60 F.
56
Hot water can freeze faster than cold water.
181
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101
Scientists aren't sure what color dinosaurs were.
312
A single speck of dust is half way in size between a subatomic particle and the Earth.
15