5614 Posted December 17, 2005 Share Posted December 17, 2005 Water would only turn to ice and anyway, Klaynos already said you can have liquid nitrogen on your hand for about 3 seconds. Link to comment Share on other sites More sharing options...
CanadaAotS Posted December 17, 2005 Author Share Posted December 17, 2005 wouldn't your the warmth of your hand intially vaporize most of the liquid helium anyways? Link to comment Share on other sites More sharing options...
Klaynos Posted December 17, 2005 Share Posted December 17, 2005 wouldn't your the warmth of your hand intially vaporize most of the liquid helium anyways? Yes, also the helium would evaporate very quickly in open air anyway. So you'd probably need to put your hand into it for any effect and it'd firstly burn you and then if you left it for longer you'd start to actually freeze the cells deeper in your skin which would be in effect a deeper burn. It wouldn't be good, and it would be worst than liquid nitrogen if only becaues it's colder so lasts longer. Which is worst putting your hand in water of 100deg C or 200deg C.... the latter is obviousely going to have more of an effect faster :| Link to comment Share on other sites More sharing options...
CanadaAotS Posted December 17, 2005 Author Share Posted December 17, 2005 well... what happens if yah dump a litre of liquid helium into several litres of 150 C water? Sounds like fun Link to comment Share on other sites More sharing options...
Klaynos Posted December 17, 2005 Share Posted December 17, 2005 I suspect that the helium evaporates before it even hits the water. Link to comment Share on other sites More sharing options...
silkworm Posted December 17, 2005 Share Posted December 17, 2005 When we did it we poured about a liter of liquid nitrogen in a styrofoam cooler and then got a cup of water from the water fountain. We poured it in all at once and the cooler just shook violently because the heat from the water caused a lot more of the nitrogen to boil off rapidly. After it settled down a little bit we fished out the ice and it was pure white because it froze so fast it had a lot of air in it. And it was frozen hard. Very very hard. We left it out after we got rid of the liquid nitrogen we left the ice out and I don't remember any of it melting. The ice was very very cold. Another cool thing to do with liquid nitrogen is cool if you have a linoluem or tiled floor (not carpet). After we were done Dr. Ho went out into the hallway and spreadout the nitrogen on the floor with one big pour. You'd be amazed out how well this sweeps the floor. But if you've ever seen a little drop of water dancing around on the surface of the hotplate, imagine that but everywhere as the nitrogen danced all around us while it boiled off. Link to comment Share on other sites More sharing options...
CanadaAotS Posted December 17, 2005 Author Share Posted December 17, 2005 You'd have some very cold floors after that Link to comment Share on other sites More sharing options...
silkworm Posted December 17, 2005 Share Posted December 17, 2005 The didn't seem cold. Just well swept. As the liquid nitrogen spread out, you cold see all of this dirt piling up at the front of it. And these floors were clean. Link to comment Share on other sites More sharing options...
Cap'n Refsmmat Posted December 17, 2005 Share Posted December 17, 2005 I'd bet liquid nitrogen would be great for schools to clean gum off of their desks with. Freeze the gum solid and chip it off. Link to comment Share on other sites More sharing options...
Klaynos Posted December 17, 2005 Share Posted December 17, 2005 It's relatively cheap and easy to make too (Your ice was probably around -50deg C, if equal amounts of liquid nitrogen and water where used, taking room temp to be around 20deg C) Link to comment Share on other sites More sharing options...
silkworm Posted December 17, 2005 Share Posted December 17, 2005 The nitrogen was in excess. It was about 1 liter of N2 versus 250mL H20, which was probably about 18ºC out of the fountain (it runs a little cold). All the rooms of that building are kept at 22ºC, when the heater works. That clump of ice was hard. If I was wearing some thick gloves, I'm sure I could have beaten someone to death with it. It was hard as a rock. Link to comment Share on other sites More sharing options...
swansont Posted December 18, 2005 Share Posted December 18, 2005 Using liquid nitrogen to make ice cream is pretty neat. Link to comment Share on other sites More sharing options...
Klaynos Posted December 18, 2005 Share Posted December 18, 2005 Using liquid nitrogen to make ice cream is pretty neat. If memory serves it's suposed to make it really smooth isn't it becaues of the speed? Link to comment Share on other sites More sharing options...
starbug1 Posted December 18, 2005 Share Posted December 18, 2005 How disatrous would it be if one were to inject liquid nitrogen intravenously into his blood stream, hypothetically speaking? Link to comment Share on other sites More sharing options...
swansont Posted December 18, 2005 Share Posted December 18, 2005 If memory serves it's suposed to make it really smooth isn't it becaues of the speed? IIRC yes - quick freezing means small crystals, which means smooth ice cream. Since you're probably a good 60 C below normal hand ice cream machines, and because the heat transfer is pretty efficient - you dump the LN right on the cream - you get that quick freezing. There's a rumor that the astronomers at work are getting a LN-cooled CCD array for one of the telescopes. I might be able to snag a few liters and do this again... Link to comment Share on other sites More sharing options...
wormholeman Posted December 19, 2005 Share Posted December 19, 2005 I beleive Nature allows absolute zero. Anything..Because if you have a temp- rature measuring device and when the temprature is lets say 2 degrees above, then if someone where to decrease the temprature then as it passes zero, it would have been at absolute zero for I don't know a nano second or a micro second or probobley even less then that. Link to comment Share on other sites More sharing options...
swansont Posted December 19, 2005 Share Posted December 19, 2005 I beleive Nature allows absolute zero. Anything..Because if you have a temp-rature measuring device and when the temprature is lets say 2 degrees above' date=' then if someone where to decrease the temprature then as it passes zero, it would have been at absolute zero for I don't know a nano second or a micro second or probobley even less then that.[/quote'] Temperature is normally an equilibrium-condition measurement, so a transient condition such as you describe does not apply. But belief doesn't enter into whether the laws of thermodynamics are correct. Link to comment Share on other sites More sharing options...
silkworm Posted December 19, 2005 Share Posted December 19, 2005 Absolute zero is the temperature of truly empty space, and is not possible anywhere else. Link to comment Share on other sites More sharing options...
swansont Posted December 19, 2005 Share Posted December 19, 2005 Absolute zero is the temperature of truly empty space, and is not possible anywhere else. To paraphrase/use a quote by Wolfgang Pauli, "That's not right That's not even wrong." Link to comment Share on other sites More sharing options...
wormholeman Posted December 19, 2005 Share Posted December 19, 2005 Temperature is normally an equilibrium-condition measurement' date=' so a transient condition such as you describe does not apply. But belief doesn't enter into whether the laws of thermodynamics are correct.[/quote'] I dont understand what your saying. All I understand from that is "dose not apply", I know when someone is talking about temprature and when they ask if someone has got to absolute zero, and when someone is saying, "has anyone got to absolute zero" I understand this as the temprature that is at a perfect zero, which I think the guy said. I know I dont know if someone has got to absolute zero, but as this thread speaks of no one has, so I thought I would point out that nature allows this to happen. I not only believe this I know this. Link to comment Share on other sites More sharing options...
wormholeman Posted December 19, 2005 Share Posted December 19, 2005 What's the significance of going to absolute zero anyway? Thats a question by the way. Link to comment Share on other sites More sharing options...
Klaynos Posted December 19, 2005 Share Posted December 19, 2005 I dont understand what your saying. All I understand from that is"dose not apply"' date=' I know when someone is talking about temprature and when they ask if someone has got to absolute zero, and when someone is saying, "has anyone got to absolute zero" I understand this as the temprature that is at a perfect zero, which I think the guy said. I know I dont know if someone has got to absolute zero, but as this thread speaks of no one has, so I thought I would point out that nature allows this to happen. I not only believe this I know this.[/quote'] How do you know this, as I understand it there are certain conditions (mostly quantum mechanical condistions) that disallow 0K ever being observed. And if something cannot be observed we have no evidence of it and no evidence of something means it probably isn't true. Link to comment Share on other sites More sharing options...
wormholeman Posted December 19, 2005 Share Posted December 19, 2005 I know this because zero dose exist. I can picture it in my mind. Picture a thermometre and put it in an enviroment where the temprature decreases past zero, now picture the red thing on the thermometre as the enviroment temp decreases, the red thing goes down because the temp go's down, zero is on the thermometre, as the temprature go's down in the enviroment it will pass zero. So naturally it was at absolute zero. How long it was at absolute zero depends how fast the temprature in the enviroment decreases. I hope you know what I mean by "red thing" Link to comment Share on other sites More sharing options...
Klaynos Posted December 19, 2005 Share Posted December 19, 2005 Temperature cannot decrease past 0K. The fact the measuring device in the thermometer was moving means it has some energy, which by the very deffinition of absolute zero it cannot have. Link to comment Share on other sites More sharing options...
wormholeman Posted December 19, 2005 Share Posted December 19, 2005 it did pass absulote zero did it not? Link to comment Share on other sites More sharing options...
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