In zero gravity, a candle's flame is round and blue.
16
One ragweed plant can release as many as one billion grains of pollen!
51
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
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
Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
15
The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
A single speck of dust is half way in size between a subatomic particle and the Earth.
15