Cows can sleep standing up, but they can only dream lying down.
745
The oldest glowing lightbulb was first switched on in 1901 and lives in fire stations in Livermore, CA. It is known as the Centennial Light.
118
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
There is a mass reservoir of water floating in space that is 100,000 times bigger than our sun and holds 140 trillion times more water than all of our oceans.
11
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21