Sound travels about 4 times faster in water than in air.
408
One cubic foot of gold weighs more than 1,200 pounds!
78
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
Most dust particles in your house are made from dead skin!
67
Your brain is 80% water.
525
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
A cubic yard of air weighs about 2 pounds at sea level.
31