When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Pure water (H2O) does not conduct electricity on its own.
46
Pumice is the only rock that floats on water.
14
The left ear is more responsive to words of love and emotion whispered into it than the right.
40
One third of the electricity produced on earth is used to power electric light bulbs!
75
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
During photosynthesis, plants emit light humans can’t see, but NASA can see that light from space - and they've even made maps of it!
21