Why Does Glass Break?

Apparently, nobody knows.

After 2,000 years of making and breaking glass, one might think there would be a definitive answer. But at the Third International Workshop on the Flow and Fracture of Advanced Glasses, held Oct. 2 to 5 at The Penn Stater Conference Center Hotel, 50 or so of the world's top glass scientists scratched their heads as researchers presented sharply conflicting views on the topic.