One cubic foot of gold weighs more than 1,200 pounds!
78
The average home creates more pollution than does the average car.
33
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
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
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Hot water can freeze faster than cold water.
181
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
The bark of an older redwood tree is fireproof.
65