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
Scientists at the Zhejiang University in China have developed an ultra-light material known as carbon aerogel.
3
A cow produces around 200,000 glasses of milk in her lifetime.
373
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
Cows can sleep standing up, but they can only dream lying down.
745
Only about 2% of the world population has green eyes.
36