Iron weighs more after it rusts.
16
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
Out of all the senses, smell is most closely linked to memory.
146
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
The force of a suction cup is calculated using F=AP.
15