Mars had an oxygen-rich atmosphere around 4 billion years ago
13
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
If you have 1 billion dollars and spend $1,000 every day, it would take you 2,740 years to go broke.
31
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
You forget 90% of your dreams.
256