4.5 pounds of sunlight strike the Earth each day.
27
Oak trees produce 2,200 acorns in a season, but each acorn only has a 1 in 10,000 chance of becoming an oak tree.
304
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Scientists have developed a microparticle filled with oxygen that can be injected into the blood stream, enabling us to live without breathing.
21
Sound travels about 4 times faster in water than in air.
408
Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
15
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6