Pumice is the only rock that floats on water.
14
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
5
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
In zero gravity, a candle's flame is round and blue.
16
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
For a high school science fair project, 17-year-old Michio Kaku built a particle accelerator in his parent's garage that was able to generate a magnetic field 20,000 times greater than the Earth's and produce collisions powerful enough to create antimatter.
34