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 oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
Cows can sleep standing up, but they can only dream lying down.
745
There is a persistent storm in Venezuela that produces lightning 140 to 160 nights a year, 10 hours per day and up to 280 times per hour and has been going since at least the 16th century.
25