The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
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
It's possible to die from a broken heart; it's called Stress Cardiomyopathy.
165
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
Some monks can increase their body temperature so much they can dry soaking sheets in a freezing room!
31
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