Glass can crack in an instant. Actually, when a crack moves down a glass surface, it can travel as fast as 3,000 miles per hour! That's faster than your car will ever go, but your car would also not be what it is without its glass windows.
When you really think about it, it's amazing that glass does not crack more often. It all comes down to choosing the right kind of glass for a certain application, and installing it properly. These are topics you can learn more about on this blog, where we crack open the truth about glass and glass items.