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 average person's skin weighs twice as much as their brain.
131
Pain occurs when sounds are above 130 db.
124
A person will create enough saliva to fill two average size swimming pools during his lifetime.
191
You can't tickle yourself.
29
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
139