It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
In 30 minutes, the average body gives off enough heat (combined) to bring a half gallon of water to boil.
198
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
In one day, adult lungs move about 10,000 litres of air.
11
There are about 255 babies born worldwide every minute.
46
Early American humans hunted car-size armadillos and used their shells for houses.
12
Your thumb is about the same size as your nose.
124
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14