Jump to content

Closest to Absolute Zero


CanadaAotS

Recommended Posts

  • Replies 100
  • Created
  • Last Reply

Top Posters In This Topic

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

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

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

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

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

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

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

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

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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.