When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
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
There are more than 270 people cryogenically frozen in the hope that one day the technology will exist that can revive them and extend their lives.
13
Billions of neutrinos pass unnoticed through your body every second.
6
Iron weighs more after it rusts.
16
A cesium atom in an atomic clock beats over nine billion times a second.
43