A single speck of dust is half way in size between a subatomic particle and the Earth.
15
Iron weighs more after it rusts.
16
Oak trees produce 2,200 acorns in a season, but each acorn only has a 1 in 10,000 chance of becoming an oak tree.
304
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Each day, up to 150 species of life become extinct.
-23
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310