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
Only about 2% of the world population has green eyes.
36
A lump of pure gold the size of a matchbox can be flattened into a sheet the size of a tennis court.
140
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
It's possible to die from a broken heart; it's called Stress Cardiomyopathy.
165
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
No one knows Albert Einstein's last words. Just before he passed, he spoke several words in German, but his nurse only knew English.
154