Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
In zero gravity, a candle's flame is round and blue.
16
Research indicates that plants grow healthier when they are stroked.
173
During photosynthesis, plants emit light humans can’t see, but NASA can see that light from space - and they've even made maps of it!
21
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
Iron weighs more after it rusts.
68