Can absolute zero ever be achieved?

[ffleming7]

Can absolute zero ever be achieved? I this a theoretical kinetic energy?

 

[Danger]

It's more a theoretical lack of energy. Although we've come very close to it with liquid helium, I don't think that it's practically attainable. You would need, to start with, a perfect insulator, which doesn't exist.

 

[nicksauce]

Isn't the point of the third law of thermodynamics that it is impossible to reach absolute zero?

 

[Danger]

Isn't the point of the third law of thermodynamics that it is impossible to reach absolute zero?

Correct, at least the way that I learned the 4 laws.
1) No matter how hard you try, the best that you can do is break even.
2) You can only break even at absolute zero.
3) Absolute zero is impossible to attain.
4) No matter how hard you shake it, the last drop always goes down your pants.

 

[Rib5]

Correct, at least the way that I learned the 4 laws.
1) No matter how hard you try, the best that you can do is break even.
2) You can only break even at absolute zero.
3) Absolute zero is impossible to attain.
4) No matter how hard you shake it, the last drop always goes down your pants.

Number 4... ROFL

 

[_Mayday_]

Correct, at least the way that I learned the 4 laws.
1) No matter how hard you try, the best that you can do is break even.
2) You can only break even at absolute zero.
3) Absolute zero is impossible to attain.
4) No matter how hard you shake it, the last drop always goes down your pants.

I hate that SO much.

If absolute zero is impossible to attain, then is it not found anywhere in the universe? Is it something that just cannot be broken, in terms of going any lower?

 

[nightshade123]

if absolute zero is obtained the universe will collapse into itself...

 

[Danger]

I'm not so sure about the collapsing part, but the universe as a whole is still permeated by the cosmic microwave backgound 'noise' from the Big Bang. That's something like 3 degrees K.. To attain absolute zero, you'd have to isolate a container of some type, and then pump out those 3 degrees. I'm not saying categorically that it's impossible, because technology continues to take me by surprise, but our current methods aren't up to it.

 

[_Mayday_]

if absolute zero is obtained the universe will collapse into itself...

Erm...why?

 

[_Mayday_]

I'm not so sure about the collapsing part, but the universe as a whole is still permeated by the cosmic microwave backgound 'noise' from the Big Bang. That's something like 3 degrees K.. To attain absolute zero, you'd have to isolate a container of some type, and then pump out those 3 degrees. I'm not saying categorically that it's impossible, because technology continues to take me by surprise, but our current methods aren't up to it.

You would also need to have perfect insulation would you not?

 

[Danger]

As mentioned in post #2, yes. I don't believe (just my opinion) that there can be such a thing, given quantum fluctuations and whatnot.

 

[PiratePhysicist]

I don't remember the the Laws of Thermodynamics forbidding absolute zero, but either way it's still impossible to attain absolute zero. To do so would be in violation of the Heisenberg Uncertainty Principle as if a particle is at absolute zero you would be able to learn it's precise position and velocity.

 

[Danger]

I never thought of it that way, but it makes sense. Its energy and movement would both be '0'.

 

[nightshade123]

and if u get particles to stop moving what do you thing will happen to everything around it...

 

[Danger]

Not much.

 

[PiratePhysicist]

Really in order for absolute zero to be achieved, which it isn't but hypothetically here, the matter being put at absolute zero would have to be secluded from all other matter and shielded from radiation. Even if it wasn't it just means that you'll start slowly cooling other stuff too.

 

[Danger]

Even if it wasn't it just means that you'll start slowly cooling other stuff too.

Bingo! And by cooling other stuff, you're gaining heat from it.

 

[staf9]

Therefore it's impossible to reach absolute zero until all atomic motion in the system (universe) has been stopped.

As has been said before, perfect insulators don't exist. If one atom isn't moving and there's an atom that is moving near it, the one that isn't moving will steal some of the energy from the moving atom and start to move.

 

[PiratePhysicist]

It's fundamentally impossible to get any part of the universe to reach absolute zero, the part about needing the insulation was just a matter of hypothetical thinking.

 

[Ki Man]

Theoretically? Yes you can reach it if you have a perfect insulator (which is impossible)

and because there does not exist a perfect insulator in the universe, as long as there is heat somewhere in the universe, its not possible. Besides, the moment you try to measure it to make sure all motion has stopped, you will have inadvertently heated it back up again. You'd be stuck with a container that you cannot touch, pointing at it and screaming eureka with absolutely no way to prove there's anything inside to begin with

 

[Loren Booda]

Photons have a spin of one, as electrons and protons have a spin of one-half; these quantum phenomena no amount of cooling can extinguish. I think it safe to assume that these residual spins involve a minimum energy (and thus temperature) greater than zero. My guess is that although absolute zero may exist at certain singularities, the very attempt to measure it would cause heating.

 

[RonL]

Having used vortex tube coolers, and finding a refrigeration manuel that explained in detail how they work, my question is, would the very center of a vortex of high velocity produce a very small center point of zero condition ?

 

[smashingtime]

My chemistry teacher said that some institute came very close to reaching absolute zero...but all the same, it will be impossible to ever attain absolute zero.

 

[Danger]

I really think that it's time for one of the 'gurus' to get involved. Someone with professional knowledge such as Zapper Z, Arildno, or Astronuc can probably put this thing to bed without us having to speculate further.

 

[arildno]

I really think that it's time for one of the 'gurus' to get involved. Someone with professional knowledge such as Zapper Z or Astronuc can probably put this thing to bed without us having to speculate further.

Post edited appropriately.

 

[Danger]

You silly ass.
Even if it's not your particular field of research, you still know a hell of a lot more about this stuff than we do.

 

[staf9]

Having used vortex tube coolers, and finding a refrigeration manuel that explained in detail how they work, my question is, would the very center of a vortex of high velocity produce a very small center point of zero condition ?

Nope, energy from the outside system would cause the center to have energy, albeit a very small amount.

Absolute zero is only possible if we have either a perfect insulator, or all atomic motion in the universe stops, both of which I don't see happening any time soon.

 

[RonL]

The PBS.ORG just aired a 2 part document " in search of absolute zero"

http://www.pbs.org/wgbh/nova/zero/

If i rember right, a temp of less than one degree was reached by MIT.
A good artical to look at for anyone interested.

Go to chapter 10 for the coldest temp recorded.

 

[greeniguana00]

I don't remember the the Laws of Thermodynamics forbidding absolute zero, but either way it's still impossible to attain absolute zero. To do so would be in violation of the Heisenberg Uncertainty Principle as if a particle is at absolute zero you would be able to learn it's precise position and velocity.

Well, it would be a violation of the Heisenberg uncertainty principle if you could detect the existence of such a particle. I don't see how its sole existence would violate it.

Also, thermodynamics seems to be a field of probability. While energy tends to flow from high to low on average, there are cases where by pure chance energy will flow in the opposite direction. Perhaps with the enormous number of particles in the universe, one has been just lucky enough to lose all its energy.

 

[f95toli]

Well, it would be a violation of the Heisenberg uncertainty principle if you could detect the existence of such a particle. I don't see how its sole existence would violate it.

Not quite. The problem is that "temperature" is a very tricky concept to define but according to the "normal" statistical way of doing it (modelling the environment as a bath of oscillators) the result is that particles will still move -albeit very slowly- at 0K due to quantum brownian motion.
However, we run into problems with temperature much earlier than this. The lowest fixed point on the international temperatures scale (ITS-90) is as high as 650mK, one reason being that once we go much below that the concept of temperature becomes very fuzzy, it is simply difficult to define it in a meaningfull way (I know a few people that work in cryogenic thermometry).
650 mK is actually a fairly high temperature so this causes some practical problems, e.g. a normal -relatively cheap- He-3 system can easily reach a temperature of about 270 mK. Dilution fridges can go to about about 10 mK (without wiring, in use most fridges have a base temperature of 20-25 mK). Hence, we routinely reach temperatures much lower than this in the lab (not counting optical cooling of gases ,where "temperatures" of nK are often recorded, but in this case the temperature is just a measure of the average kinetic energy for a relatively small number of atoms.)
Note that when I write "reach" I mean that this is the temperature indicated by the temperature sensors (e.g. ohmic sensors like RuO2 or nuclear orientation thermometers), but this does not mean that it is the "physical" temperature of the system being probed in the experiment , that temperature can be much higher (a point which is often overlooked by people without enough experience).