I just learned something

[Megafrost]

Whatever you do, do not take a very warm cup and pour a cold drink into it. Unfortunately for me, I learned this the hard way, as my glass split into two pieces as I was holding it. And the tea? All over the floor now.

[taenadar]

awww too bad of the tea
anyway, dont they say glass pieces or whatever will give luck?

[Nyufrost]

Heh ... the luck is that he didn't cut his hand ...

[Megafrost]

Or it might give bad luck, because when the glass split, it was up to me to clean up the mess.

[Gigafrost]

So, do y'all know why it breaks? Me neither, but I've got a pretty good idea...

-When something becomes hot the molecules expand, thus it wouldn't be unreasonable to think that all the glass molecules had expanded more than usual (ie, room temperature)

-By adding cold liquid, in essence the molecules slowed down\contracted. Really, though, what happened was the energy from the molecules in the glass transferred into the colder fluid, since cold is lack of energy.

-But pouring the cold liquid into the cup caused uneven distributions of cold throughout the glass. Some parts contracted faster than others. This means that some parts of the glass were pushing out while others were pushing in.

-The force generated by that was probably enough to force slightly warm areas away from slightly cool areas, cracking the material and breaking the glass.

There. I do know *some* physics, even if I haven't taken a class on one.

[Drazo]

hmm.....that's never happend to me before, i fill the glass up with scorching hot water to kill off any germs and then (after i tip it out) fill it up with cold water and pour it out.
Yes I do this every time I have a glass of something and yes I am fussy about germs and hygine in what I consume.

[Evlfrost]

Wait a minute! You said you learned something? Tell me, where do you store everything you learn if you dont have a brain (fyi Mega sold his brain to the devil to get his soul back, then turned around and sold his soul to Runescape for smithing levels and he doesnt remember what he originally sold his soul for).

[Megafrost]

Tell me, where do you store everything you learn if you dont have a brain

It gets stored in my hollow head, and then it eventually leaves to go find the devil who has my brain.

Wait, what did I learn again?

[Gigafrost]

hmm.....that's never happend to me before, i fill the glass up with scorching hot water to kill off any germs and then (after i tip it out) fill it up with cold water and pour it out.
Yes I do this every time I have a glass of something and yes I am fussy about germs and hygine in what I consume.

But I don't think this is what Megafrost did, exactly. If I were to guess, he took something out of the dishwasher that was really warm...I mean thuroughly warmed. I'd imagine that in your case there is a little force involved but most likely insignificant.

[Roadkill]

it must have been an old glass, or very thin glass. i do it all the time and im safe (though we dont turn heat dry on anymore since it makes food stick)

[Toby]

Hahahahahaha did u Know that u can push the middle of a $2 Candain coin out if it hot and the outside is cold?

[Roadkill]

i would love to find a canadian $2 coin. i havent seen one in a while, and it was my favorite coin design.

[Nyufrost]

I think Canadian dollars is slightly off topic, no?

Dragon, do you --perhaps-- use hot and cold tap water to rinse your glass? If so, that wouldn't be a big enough difference. I suspect maybe Mega took a glass out of the dishwasher and poured cold tea from the refrigerator?

Here is another weird thing about dishes ... sometimes if you stack glasses or bowls inside of one another in the sink when they are wet they may go together ok but then just try to get them apart! It's like the one inside has suddenly gotten too big but I think it is some sort of vacuum principle.

[OmegaFrost]

The problem isnt that the water is contracting and expanding the glass is for whe you poor freesing water into the glass the glass gets cold and contracts ever so slightley if you then heat up the glass (this works both ways mind you) then it may expand to quickly causing it to crack. Theoritcally if you change the temperature of anything too fast it will crack. So dont drink coffe then spontaneosly dump ice water into youre mouth or you will crack a tooth(it would require you to be really really fast for that to happen).