Iron weighs more after it rusts.
68
Cold water weighs more than hot water.
93
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
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
Hot water can freeze faster than cold water.
181
Columbia University has developed an artificial tree that passively soaks up carbon dioxide from the air using "leaves" that are 1,000 times more efficient than true leaves that use photosynthesis.
15
Diamonds can be shattered with a hammer.
-104
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199