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
The 409 escalators in the London subway cover a distance every week which is approximately equivalent to several trips around the globe!
94
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
There are so many kinds of apples that if you ate a new one everyday, it would take over 20 years to try them all.
34
The strangers in your dreams are actually people that you've seen in real life.
50