Why did my glass plate explode?

[GrandMasterK]

I was cooking a roast on one of those glass pans with the sides only a couple inches tall. Had it in the oven for 45 minutes at 350 degrees. I take it out and let it sit there while I ran back to the TV to see what was happening. All of sudden "KUUURSCH!". I come back, and there is glass and juice all over the kitchen. The roast had glass stuck to it like someone was shooting a glass gun at it. It took me 3 hours to clean up.

 

What is the science behind this?

[Phi for All]

Most likely it was a Pyrex pan and you've probably had it for years. After going in and out of the oven so many times Pyrex can develop stress fractures from thermal fatigue. Sometimes tiny scratches can add to the stress as well.

 

I've noticed that Pyrex is really tough but when it goes it goes big time. I've dropped Pyrex from three feet or more onto hardwood and tile and it hasn't broken. Once I dropped a measuring cup and it landed just wrong and literally blew up, throwing pieces all over the kitchen.

[s pepperchin]

It depends on the temperature and the condition. If there is a sudden change in temperature sometimes materials can't handle the sudden change. I saw a show on TLC once about emergency rooms where a lady placed a hot pan directly on a glass table. She came into the ER because when she set it down the sudden change in temperature caused the glass to shatter, and thinking quickly the lady caught the pan under the table (without hot pads).

 

I know it seems like the opposite idea but If the room or table was the right temperature it could have caused rapid cooling in the pan. The pan probably just couldn't handle the stress.

[anglepose]

mayb there was tiny air bubbles in the pan and the air expanded and so the glass shattered

[YT2095]

what did you let it rest on when you took it out?

 

as it`s quite possible that the material it was on has a high temperature conductance and cooled the outside faster than the inside cooled, and as you know, when things cool they contract (heat will Expand materials), it`s likely the difference was too great in the Pulling effect of the outside "Skin" to the expanded inside, and it Pops like a balloon.