The strangers in your dreams are actually people that you've seen in real life.
50
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
Your body is creating and killing about 2.4 million red blood cells per second.
17
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