Iron weighs more after it rusts.
16
Sound travels about 4 times faster in water than in air.
408
According to studies, men change their minds two to three times more often than women.
72
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
Nearly 50% of the world's scientists are assigned to military projects.
71
Pumice is the only rock that floats on water.
14
MIT has developed a camera that captures the speed of light at a trillion frames per second.
20
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108