In zero gravity, a candle's flame is round and blue.
16
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
The sun is 330,330 times larger than the earth.
75
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
No matter how cold it gets, gasoline will not freeze.
107
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