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Posted

The 'universe' has two obvious boundary conditions for present time man,

 

vacuum-speed light and 0 kelvin.

 

Does there really exist any one place in our Minkowski world where one may say 0 Kelvin is the temperature here? how accurate would that claim be? macroscopic? microscopic, subatomic? string level?

 

(And sure, a reply on the thread question : the empty space where electrons make their leaps of faith, must of course be 0 Kelvin?)

 

 

But then I wonder if any part of the space-time 'fabric' or call it empty space (for arguments sake I guess we would say between two neutrinos eh?) actually can have 0 Kelvin... the more intrinsic question is of course if space itself is indivisible with respect to virtual particles, various fields you name it :)

 

 

me w00tles

 

hoping for interesting thoughts

Posted

In terms of temperature of "empty space" being measured, I think that you can't really measure "nothing".

I'm not sure if my thinking is correct, but temperature is a measure of energy or activity in a substance. And to say that something is 0 Kelvin would mean it has 0 activity. And for that measurement to be found you need to have something to test, therefore testing nothing gives an invalid result.

 

Please tell me if this is wrong or doesn't make sense.

Posted

not at all gonelli, it makes very much sense...although just like you say intuitively it seems like a very silly question..but it is not. Since space-time is connected to matter, and energy one would think that 'nothingness' in space-time is different from 'nothingness' beyond the visible universe? If we go along with big bang ideas etc, 0 K in 'non-reached' infinity is fine (these are not necessarily my understandings, just in case loads of people from those very funny long threads on what is beyond the universe come along.); however I still wonder if background noise (~3 K) is more subtly connected with [empty] space itself (I think this is something else yes) or *if* accurate enough sensors, we could predict a infinesimally small deviation from 0 K in any given point in Minkowski space.... I mean with our super tanks deep in the ground we have managed to indicate neutrinos for the love of God ;) we might actually have a shot on figuring out just how connected space and matter really is on the very fundamental level...again I reiterate, I might easier be convinced of some (continuous????) transition of energy/heat to be predicted between vacuum space and occupied space (aka matter).

 

Although all which you said makes as much sense to me as it does to you :)

 

lakmilis

Posted

oh oh, and yes Gonelli, just as you say, 0 K would indicate no energy in a substance, thus I wonder could we measure the temperature between electron shells? Yes, like you say, a deeper question I am posing here then, is if space with no apparent matter present, really is 'nothing'. From that same inference we could not then 'imagine' that nothingness can curve like space-time does right :)

After all quantum leaps we just have to take for granted...to explain how they[electrons] actually move between them[electron shells] is something else than just being able to visualise and accept them to work with them :)

Posted

I have one small problem with this. Ponder the following.

 

Tempreature is a measure of the average kinetic energy of particles in a system. In the absence of particles, can a temperature exist?

 

Of course there are the vacuum fluctuations, are you familiar with them?

Posted

Yes, and by looking at other posts just now, it seems like this is the zero point energy realm...in any case... No, I still believe if we are to accept GR topology (or Minkowski space) one almost *has* to realize there must be non-0 Kelvin temp in any point in Minkowski space.

 

 

(And no, I am aware *of* the vacuum fluctuations, do not have any awareness of manipulating nor relating the effective formulas :) )

 

Oh, and in answer to the pondering, can temperature exist with no particles...well that is kind of what I am pondering about with the thread :)

 

lakmilis

Posted

drochaid> Klaynos, lies, I drink urine and call it beer

 

PHILOSOPHY AND YOUR RANDOM THOUGHTS ARE NOT SCIENCE DO NOT POST THEM AS SUCH

 

 

hehe, and is drinking urine and calling it beer not random thoughts ;)

 

doesnt matter, science is a subset of philosophy, if one can't post them here , then I posted this at perhaps an incorrect forum :)

 

I did see Servian or something also say 'philosophical nutters' come this way... not much science can be done then however...just calculations :)

Posted

I'd say that if we ignore vacuum fluctuations then no 'empty' space cannot have a temperature. Because of what the definition of temperature is.

 

Of course if you allow for vacuum fluctuations then you actually have particles, which is why I bring them up... ;)

 

My apologies if I don't reply again, I'm supposed to be revising statistical mechanics this afternoon... ;)

 

</on topic>

drochaid> Klaynos, lies, I drink urine and call it beer

 

PHILOSOPHY AND YOUR RANDOM THOUGHTS ARE NOT SCIENCE DO NOT POST THEM AS SUCH

 

 

hehe, and is drinking urine and calling it beer not random thoughts ;)

 

doesnt matter, science is a subset of philosophy, if one can't post them here , then I posted this at perhaps an incorrect forum :)

 

I did see Servian or something also say 'philosophical nutters' come this way... not much science can be done then however...just calculations :)

 

There's a difference between posting your ideas, and posting your ideas as facts. As for the beer comment, well it is random, but droch said it not me...

Posted

Two words "Unruh radiation".

 

The temperature of "empty space" depends on the observer!

Posted

Hi ajb, from other posts, I have an inclination to look forward to your input..

 

however, two words...unruh sounds like stargate babble ot me ;p hihi

 

going into reference frames and even observer crosses too much into my slightly different metaphysics than the normal scientific approach. Relativistic temperature hehe, let me just ask if I am getting you right...are you saying that we can choose a reference frame in such a way, that 0 Kelvin could always be avoided? That we have no way to determine if a certain 'system' (or secluded part of space perhaps?) is indeed in 0 K state?

 

I just have this feeling you see, that 0 K is as much a physical boundary of the current space view we have as c ( vacuum wave propagation) is :)

Posted

I don't think that "relativistic theormodymanics" is well understood. I don't think it is clear how temperature should transform under a Lorentz transformation or that it should be Lorentz invariant.

 

But that is not what I was hinting at. What i do know, is that a noninertial observer will appear to himself to be in a warm bath of radiation proportinal to his proper acceleration. This is due to the lack of a well defined vacuum for all observers. This is the Unruh effect.

 

Thus the notion of a temperature of the vacuum is ambiguous.

Posted

Hmm, sure, but if a person is accelerating or indeed has any internal (as a local system) thermal energy , which indeed it must have to be able to observe, there are possible interactions again which as you say could make thermal vacuum interpretation ambiguous. Hmm, well unruh effect or not...clearly we know that from Heisenberg as such, we can not really measure the temperature....ah nevermind, I am starting to see the question is indeed valid but it goes into entirely other aspects...

 

I think I might have something to preoccupy me soon enough :)

 

(Oh, and I really wouldn't think temperature is a Lorentz-variable.. it should remain invariant, although just now I am not so sure anymore ^^)

Posted

OK, the idea of 0K as the temp between electron shells is compleatly absurd, no offence, but 0K is where no energy exist. And since there is energy between electron shells, the temp thus cannot be 0K. Now, according to einstein, space and time cannot be seperated. But if you are looking for 0K, look just inside the event horizon of a black hole, where space is isolated from time (thus no energy because things cannot move or change which requires energy) then there will be 0K, or no temp.

Posted

Swansont, I was just thinking the same, what is this ''between electron shells''

 

are you refering to the forbiden gap ? If so, I dont know what relivance it has in this situation...

Posted

To my understanding the only way that 0 k could be perceived truly is if the space between the electrons were seen as a true perfect vacuum; however the idea of a perfect vacuum is problamatic at best for instance light in the form of black-body radiation would be emited by the walls of the vacuum chamber. Also the Heisenberg uncertainty principle must be taken into account.I cannot see 0 kelvin being feasibly attained.

Posted

swansont...That is exactly what the thread kind of asks about...if it is spatial or energy...if energy, by definition we say no energy can exist as such between the quantum levels, yet we conceptualise a factual spatial existence between these shells. If that is the case, the 0 K question I guess had more to do with vacuum energy density yes. If ,as someone called it, it is a forbidden zone of energy , then this zone must have 0 energy density, thus 0 K. But then as someone else implicitly spoke about, things like the Casimir effect gets fuzzy.

 

And Infinitus, funny I use a similar nick myself many places and I agree perfectly with your deductions. However as you say, it gets problematic..was just looking for any clear replies.

 

lak

 

ps. Infinitus, nice signature but you need to add 'to' between 'has' and 'be' and intellectual has a typo :)

Posted

Slightly off-topic (not sure what the topic is, anyways):

I don't think that "relativistic theormodymanics" is well understood. I don't think it is clear how temperature should transform under a Lorentz transformation or that it should be Lorentz invariant.

I was under the impression that temperature is a scalar. In fact, I think I even read it as an example of a scalar, so it's probably not only an idea of mine. After all, it's just a label for the energy distribution we expect at a certain point in spacetime. Sure, the individual energies depend on the frame, but that's not really something that's specific to relativity - Newtonian mechanics also has frame-dependent energies.

Posted

It is not something I know much about, but I do know that Planck and the later Ott showed that temperature is not a Lorentz invariant, however they got different transformation laws!

 

What they both assumes (I think) is that Boltzmann's constant is Lorentz invariant. If you allow it to transform then it is possible to get an invariant temperature.

 

You will have to find out the details yourself, it is not something I have looked into myself.

This article in the Russian Journal of Physical Chemistry is a good place to start.

Posted
swansont...That is exactly what the thread kind of asks about...if it is spatial or energy...if energy, by definition we say no energy can exist as such between the quantum levels, yet we conceptualise a factual spatial existence between these shells. If that is the case, the 0 K question I guess had more to do with vacuum energy density yes. If ,as someone called it, it is a forbidden zone of energy , then this zone must have 0 energy density, thus 0 K. But then as someone else implicitly spoke about, things like the Casimir effect gets fuzzy.

 

No, the thread asks if the temperature between electron shells is 0 K. But it does not define what "between electron shells" means. If it refers to a spatial "between," then it is ill-defined, because shells can overlap. If it's between in the energy parameter, then it's just ill-defined.

 

Anyway, temperature isn't defined for "empty" space or small numbers of particles; it's meaningless. T is a property of an ensemble under certain conditions. And 0 K is unattainable for the situations where it has meaning.

Posted
It is not something I know much about, but I do know that Planck and the later Ott showed that temperature is not a Lorentz invariant, however they got different transformation laws!

 

What they both assumes (I think) is that Boltzmann's constant is Lorentz invariant. If you allow it to transform then it is possible to get an invariant temperature.

 

You will have to find out the details yourself, it is not something I have looked into myself.

This article in the Russian Journal of Physical Chemistry is a good place to start.

 

thanks ajb. I know the topic would sound a lil silly, but there is reason for it

 

I'll look for it when I have time. The coming weeks are gonna be a bit bogged down

Posted
I don't think that "relativistic theormodymanics" is well understood. I don't think it is clear how temperature should transform under a Lorentz transformation or that it should be Lorentz invariant.

 

But that is not what I was hinting at. What i do know, is that a noninertial observer will appear to himself to be in a warm bath of radiation proportinal to his proper acceleration. This is due to the lack of a well defined vacuum for all observers. This is the Unruh effect.

 

Thus the notion of a temperature of the vacuum is ambiguous.

 

So can an observer be brought down to O Kelvin? I understand the reference frame a bit, but I don’t see how the observer, or two of them then could ever come to understand anything really, it would basically in my opinion put forward some postulate that the universe and everything basically is nothing more then the uncertainty principal? Maybe time really does fly when you are having fun;) I mean BEC, which is recorded by observers to be within a billionth of a degree from absolute zero does occur in labs. Subsequently something occurs to the matter or particles at that point. I would think that if the "nothing" of space had some particle nature to it, something similar would occur then?

Posted
So can an observer be brought down to O Kelvin?

 

You mean by a Lorentz transformation?

 

If so just have a look at the article I cite.

 

If temperature is Lorentz invariant then no.

 

If temperature is dependent on the intertial reference frame we have two different opinions;

 

1) Planck

 

[math]T_{u} = T_{o}(1- \beta^{2})^{\frac{1}{2}}[/math]

 

where [math]\beta = \frac{u}{c}[/math], [math]u[/math] being the speed of the moving frame.

 

[math]\beta^{2} = 1[/math] when [math]u = c[/math]. So yes, it could be Lorentz boosted to zero, but only if it moves at the speed of light.

 

 

2)Ott

 

[math]T_{u} = T_{o}(1- \beta^{2})^{-\frac{1}{2}}[/math]

 

Now at [math]u = c[/math] we have an infinite temperature! For [math]T_{u}[/math] to be zero we require [math]1- \beta^{2}[/math] to be big but [math]\beta^{2}[/math] is real and less that [math]1 [/math]

 

Of course what I have said does not include quantum mechanics, which gives us the notion of absolute zero.

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