Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
One barrel of petroleum holds 42 gallons.
20
A ball of glass will bounce higher than a ball made of rubber.
73
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
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
The bark of an older redwood tree is fireproof.
65
Your brain is 80% water.
525