When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
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
In zero gravity, a candle's flame is round and blue.
16
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
Out of all the senses, smell is most closely linked to memory.
146
The only letter not appearing on the Periodic Table is the letter "J".
180
Diamonds can be shattered with a hammer.
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