Sound travels fifteen times faster through steel than through air.
134
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
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
The only letter not appearing on the Periodic Table is the letter "J".
180
For every gallon of sea water, you get more than a quarter pound of salt.
45
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
Iron weighs more after it rusts.
16