Pumice is the only rock that floats on water.
14
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
One cubic foot of gold weighs more than 1,200 pounds!
78
There are more than 270 people cryogenically frozen in the hope that one day the technology will exist that can revive them and extend their lives.
13
Your brain is 80% water.
525
Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
15
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