[QUOTE=zombini;35024831]I do think this is partly because of the students as well, considering that they willingly held it for so long, it's not like the teacher made them hold it for that long. And even if he did, they can just drop it, and leave the classroom and tell the administration about the teacher making them hold pieces of hazardously cold ice without proper protection. A side note here, why the hell were they playing with dry ice anyways? At my school in missouri, the school is so scared to death that they won't do anything with dry ice or liquid nitrogen, hell, i had a little tiny vial of mercury i wanted to show my teacher and she flipped the fuck out, told me about the fancy cleanup procedure if i spilled any, and i was suspended for having it, and the confiscated it and gave it to the police.
[editline]6th March 2012[/editline]
If you had really clean hands prior to handling an extremely cold substance, that actually would cause heat conduction to occur faster because human flesh conducts heat pretty well. And the trick to holding dry ice for extended periods of time without gloves is to keep it constantly moving so you don't get frostbitten.[/QUOTE]
The layer of gas in-between my hands and the dry ice doesn't conduct very well that is why if I had dirt on my hands it would freeze my cells because it conducts much quicker. Go ask your University professor he'll tell you. This was back in first year chemistry so I can't give all the details as to how.
To clear this up by hold I mean 2-3 seconds then move it again and repeat. I also don't think giving it to any child was a good idea.
[QUOTE=Diealready;35024884]The principle with the mythbusters molten lead experiment was that you could dip your hand in it for a fraction of a second if your hand was wet, which is possible, but completely different than holding dry ice without gloves for a minute.
Dry ice is CO[sub]2[/sub] gas in a solid state (iirc), so naturally it's extremely cold. I'd imagine that if you held dry ice without gloves and your hands were wet, it'd just freeze to your hands.[/QUOTE]
By principal I'm referring to the air acting as a buffer just like the water did, but obviously the air doesn't evaporate which is why you can only hold it for so long without moving it again. I actually held it anyway so...
Reminds me of that one experiment which tested how people reacted to authority figures.
It would appear all the students failed the test
I've never learned anything about this, what exactly does dry ice do?
[QUOTE=zombini;35024831]I do think this is partly because of the students as well, considering that they willingly held it for so long, it's not like the teacher made them hold it for that long. And even if he did, they can just drop it, and leave the classroom and tell the administration about the teacher making them hold pieces of hazardously cold ice without proper protection. A side note here, why the hell were they playing with dry ice anyways? At my school in missouri, the school is so scared to death that they won't do anything with dry ice or liquid nitrogen, hell, i had a little tiny vial of mercury i wanted to show my teacher and she flipped the fuck out, told me about the fancy cleanup procedure if i spilled any, and i was suspended for having it, and the confiscated it and gave it to the police.[/QUOTE]
there's the unspoken assumption that
a) they'll be punished by the teacher if they do not
b) everyone else is doing it, and being the first dissenter is much harder than being the second or third
imagine holding frozen fire
[QUOTE=Starship;35025068]I've never learned anything about this, what exactly does dry ice do?[/QUOTE]
[url]http://en.wikipedia.org/wiki/Dry_ice[/url]
[quote]The extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing (frostbite).[/quote]
[QUOTE=KingKombat;35025087]imagine holding frozen fire[/QUOTE]
I don't think most people [I]can[/I]
I mean it'd be cold I guess
[QUOTE=KingKombat;35025087]imagine holding frozen fire[/QUOTE]
Now THAT'S an ice burn
surely the kids should of realised after a couple got hurt
[QUOTE=DainBramageStudios;35024243][url]http://aca.ninemsn.com.au/article/8430165/school-science-video-shock[/url][/QUOTE]
ACA, are you kidding me?
Honestly, what i'm concerned about is why student after screaming student, that these kids picked it up.
I get the whole competition, but when you start to hear them SCREAM THAT LOUDLY with those blisters on their hands, why in god's name do you walk up and pick some up yourself?
Most of these kids are idiots, you can plainly see as the kids walk away with blisters swelling all over their hands and still crying about the pain that more students walk up and give it a go.
At least they don't have to go back to school for a while.
:v:
how the fuck do you become a teacher and not know dry ice does this to you
there are so many things wrong with the way the educational system is run these days
The kids are just as fucking retarded as the teacher, imo.
[QUOTE=zombini;35024743]Actually, this is different, the reason behind the putting your finger in molten lead works, is because they wet their fingers and dipped it in, flash boiling the water on their fingers, making a little bit of steam that isn't really all that heat conductive. This is a solid chunk of frozen Co2 which sublimes constantly, and the Co2 coming from it is always near the same temperature as the dry ice.[/QUOTE]
It IS the same temperature as the dry ice. Latent heat doesn't influence temperature.
If you watch the video, the teacher wasnt in any way forcing the kids to hold it like this implies. The kids were doing it because they were sort of challenging each other to see who could hold it the longest.. He should have stopped them, but the kids are the biggest fucking retards here.
You know you can hold dry ice bare handed as long as you wet it, and your hands, beforehand? It creates a thin layer of frozen water between your skin and the frozen CO2 that won't bind to your skin.
It said in the video it the kids were allowed to do it, ie. the teacher didn't make them hold it. Still, he should have done something, but it looks like the ice was sticking to their skin. Gross.
my teacher never gave us gloves when we did dry ice stuff and no one in my class got [I]ICE BURNS!!!1![/I] therefore I declare the students stupid.
How old were these kids exactly?
A few of them at least had to know what dry ice does to your bare skin.
To the "Why don't they just drop it" people... Wouldn't it freeze to their hands like a normal ice cube, and rip off chunks of skin when pulled off?
The teacher was the one who set the task to see how long they could hold it in their hands for and had them time it and put it on the board. The kids probably didn't realise it would be as cold as it was and the blisters probably didn't start coming up until half the kids had already taken their turns.
[QUOTE=woolio1;35026039]To the "Why don't they just drop it" people... Wouldn't it freeze to their hands like a normal ice cube, and rip off chunks of skin when pulled off?[/QUOTE]
You can still shake it off or flick it off using your fingernails
[QUOTE=tom1029;35025801]If you watch the video, the teacher wasnt in any way forcing the kids to hold it like this implies. The kids were doing it because they were sort of challenging each other to see who could hold it the longest.. He should have stopped them, but the kids are the biggest fucking retards here.[/QUOTE]
peer pressure
I for one want to know what the hell was going through the teachers head when he was sitting there.
If you leave dry ice out in the air for a minute or two, it will accumulate a layer of frozen water vapor on the outside of it, in which case you can pick it up without gloves.
[QUOTE=Chicken_Chaser;35024294]Fire the teacher.[/QUOTE]
Ice the teacher.
Sorry, you need to Log In to post a reply to this thread.
