Age man used obsidian (a naturally formed glass) for cutting tools and weapons.
In 1500bc, we believe the first glass bottles were made using the “Core-Forming Method”.
Glass takes over 1 million years to decompose in our landfills and dumps.
The energy saved from recycling 1 glass bottle can run a 100-watt bulb for 4 hours.
Recycling glass reduces air pollution by 20%, and water pollution by 50%.
Only 27% of the glass used in the United States is recycled. A typical glass recycling factory can recycle up to 20 tons of glass per hour.
The largest glass furnaces produce more than 400 tonnes - more than 1 million bottles each day!
Glass manufacture had developed in Venice by the time of the Crusades (A.D. 1096-1270), and by the 1290’s an elaborate guild system of glass workers had been set up.
Thin-glass goblets can vibrate when hit by sound waves. This is due to resonance. Some singers listen to the note produced when a glass, so that their voice vibrates the glass so much that it shatters.
Hydrofluoric acid will dissolve glass.
When glass breaks, the cracks move at speeds of up to 3,000 miles per hour.
Source: http://www.strange-facts.info/interesting-glass-facts
Subject: Interesting glass facts 
Thu Mar 25 2010, 13:00
