Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
Balsa wood is classified as a hard wood!
41
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
One gallon of used motor oil can ruin approximately one million gallons of fresh water!
71
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
Cellophane is not made of plastic. It is made from a plant fiber, cellulose, which has been shredded and aged.
44
