Every four days the world's population increases by one million people.
An average adult human has skin weighing about 6 pounds in total.
The human head is a quarter of our total length at birth, but only an eighth of our total length by the time we reach adulthood.
While we're awake, our brain generates enough power to illuminate a light bulb of 25 watts.
Your blood vessels, if laid end to end, would encircle the globe twice over.
Young male gorillas usually leave their family group when they are about 11 years old and have their own family group by the age of 15 years old. Young female gorillas join a new group at about 8 years old.
Sound travels 4 times faster in water than it does through air.
Human eyes can distinguish as many as 10 million distinct color variations.
Twenty percent of Earth's oxygen is produced by the Amazon forest.
A dollar can be made into small change in 293 ways.