eli5: Why is it that glass shatters when it goes from extremely hot to extremely cold temperatures and vice versa? Moreover, what does that say about the glass manufacturing process if anything? Thank you!

Question

I just saw a video of people shattering Pyrex glass by pouring ice cold water within the measuring cup after heating it with a blowtorch, and I am curious as to what causes the shattering!

Here’s a link to the video if anyone is interested:

Thanks in advance to anyone responding!

In: Chemistry

Answer 1

All materials expand and contract with temperature. If you heat the bottom of a glass but not the top, then the bottom will expand and the top will not. Since glass isn’t very flexible, it instead just breaks.

This means that the whole temperature must be virtually the same as it heats or cools.