smashing cold emptied glasses

[meredith101]

I saw a dude drink from a glass full of really cold water with ice in it, downed the lot. The glass then shattered, as if he planned it. why would this be?

[Physicsgirl]

The only thing I can think is that the glass started to come back up to temperature too quickly and unevenly. The resulting stress in the glass (as some of it expanded whilst some didn't) caused it to break. This happens a lot with glassware if it's been hot and then gets cooled down quickly. It also happens if glass-blowers don't let their pieces cool slowly - after a few minutes it just shatters.
Also, if he put it down on the table too firmly the additional impact could have helped.
Hope this helps.

[meredith101]

thanks, it does
the room was fairly warm and i think he did put it down hard.

[Physicsgirl]

glad to be useful!