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
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
A lump of pure gold the size of a matchbox can be flattened into a sheet the size of a tennis court.
140
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
If Earth's history was condensed into twenty-four hours, life would've appeared at around 4am, land plants at 10:24pm, dinosaur extinction at 11:41pm, and human history would’ve began at 11:58:43pm.
21
Only about 2% of the world population has green eyes.
36
Cows can sleep standing up, but they can only dream lying down.
745