Pumice is the only rock that floats on water.
14
In zero gravity, a candle's flame is round and blue.
16
Iron weighs more after it rusts.
16
The bark of an older redwood tree is fireproof.
65
Pure water (H2O) does not conduct electricity on its own.
46
A cubic yard of air weighs about 2 pounds at sea level.
31
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6
Scientists at the Zhejiang University in China have developed an ultra-light material known as carbon aerogel.
3