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
One 75-watt bulb gives more light than three 25-watt bulbs.
57
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
One barrel of petroleum holds 42 gallons.
20
Cellophane is not made of plastic. It is made from a plant fiber, cellulose, which has been shredded and aged.
44
Most dust particles in your house come from dead skin.
48
Aluminum used to be more valuable than gold!
84