Pumice is the only rock that floats on water.
14
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
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
A ball of glass will bounce higher than a ball made of rubber.
73
There are more atoms in one teaspoon of water than there are teaspoons of water in the Atlantic Ocean.
13
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Iron weighs more after it rusts.
16