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
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
In the last 7 years, humanity has discovered 43 potentially habitable planets.
14
You forget 90% of your dreams.
256
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
If you have 1 billion dollars and spend $1,000 every day, it would take you 2,740 years to go broke.
31