In 1693, the postage rate of a letter was determined by how much light went through the letter. The less the light went through the letter the more expensive the rate would be. This technique was referred to as candling.

Thomas Watson, who was the chairman of IBM in 1943 predicted that their would probably only be a world market for five computers.

More than 180 countries celebrate Earth Day together every April 22nd.

AMAZING FACTS