A person will create enough saliva to fill two average size swimming pools during his lifetime.
191
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
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
Early American humans hunted car-size armadillos and used their shells for houses.
12
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Our brains have a negativity bias and will remember bad memories more than good ones.
15