Can we never make below 0K?

[alpha2cen]

Present we never make below 0K.

And Thermodynamic law tells us there is no degree below 0K.

Why we do not make below 0K?

Are there any materials below zero?

For example unknown matter. We say it Dark-matter.

Are there any possibilities below 0K Dark Matter existence? It's freely moving below 0K.

[Cap'n Refsmmat]

There's sort of a weird sense of below-0K temperatures, though it's not really "colder." See the following article:

 

http://www.newscientist.com/article/mg20827893.500-how-to-create-temperatures-below-absolute-zero.html

[alpha2cen]

Then we have to modify the 3rd law.

If negative temperature were existence, this equation would be correct.

 

Same material , no latent heat between two temperatures.

 

-5 K , 1g + 5 K , 1g -----> 0 K , 2g

 

How to define negative scale?

Edited December 7, 2010 by alpha2cen

[swansont]

Negative temperatures are not naturally occurring and are not equilibrium (or steady-state) conditions.

 

Then we have to modify the 3rd law.

If negative temperature were existence, this equation would be correct.

 

Same material , no latent heat between two temperatures.

 

-5 K , 1g + 5 K , 1g -----> 0 K , 2g

 

How to define negative scale?

 

I suspect that a substance's specific heat capacity for a negative temperature will not be the same as for a positive temperature.

[alpha2cen]

Negative temperatures are not naturally occurring and are not equilibrium (or steady-state) conditions.

 

 

So the negative temperature is made by controlling the uncontrolled physical parameter existed 0K.

It's not the common heat capacity which is related to the molecular motion(vibration, rotation, ...).

 

http://www.newscient...olute-zero.html

 

from Cap'n Refsmmat.

This is one of uncontrolled parameter control.

[swansont]

So the negative temperature is made by controlling the uncontrolled physical parameter existed 0K.

It's not the common heat capacity which is related to the molecular motion(vibration, rotation, ...).

 

http://www.newscient...olute-zero.html

 

from Cap'n Refsmmat.

This is one of uncontrolled parameter control.

 

I don't know what you mean by "uncontrolled parameter control." It appears to be an oxymoron.

 

One problem with relying on pop-sci articles is that they are not written by scientists and they miss things. Achieving "negative temperatures" is not a new phenomenon. The population inversion of a laser is an example of a negative-temperature system.

[D H]

How to define negative scale?

 

The wikipedia article on negative temperature, http://en.wikipedia.org/wiki/Negative_temperature, quotes Kittel and Kroemer in defining the temperature scale from cold to hot as "+0 K, . . . , +300 K, . . . , +∞ K, −∞ K, . . . , −300 K, . . . , −0 K"

 

The reason these negative temperatures arise is from the thermodynamic definition of temperature,

 

[math]\frac 1 T = \frac{dS}{dE}[/math]

 

In most systems, increasing the energy of the system increases the number of states in which the system can be. The number of possible states and entropy are closely aligned concepts. Thus in most systems, increasing the energy increases the entropy. However, for a system that have a maximum possible energy, increasing the system energy will at some point result in a decrease in the possible number of states. [math]dS/dE[/math], the multiplicative inverse of temperature, is zero at this point and is negative at higher energy levels. Thus the thermodynamic temperature is infinite at the point where the number of possible states reaches its maximum and is negative for even higher energy levels.

 

A negative temperature does not mean that the system has suddenly become very cold. It instead means that it has become very, very hot.

 

 

[alpha2cen]

I don't know what you mean by "uncontrolled parameter control." It appears to be an oxymoron.

 

 

How to make near 0K?

 

Is it possible to remove the heat without more lower temperature?

 

" uncontrolled parameter " means any entropy whch exists at 0K, not molecular or electrical.

But it is required to be 0K, its more basic entropy like particle wave.

[ydoaPs]

A negative temperature does not mean that the system has suddenly become very cold. It instead means that it has become very, very hot.

So, -1K is nowhere near 0K?

[D H]

So, -1K is nowhere near 0K?

Exactly. It is, however, close to -0K. There is a funny thing about a system with a negative temperature. Plop it down next to a system with a positive temperature. Heat will flow from the system with negative temperature to the system with positive temperature. The system with a negative temperature is "hotter" than the one with a positive temperature.

 

A couple of lay references:

A recent Science News article: http://www.sciencenews.org/view/generic/id/66435/title/Negative_temperature,_infinitely_hot

Physics FAQ article: http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/neg_temperature.html

 

 

 

[alpha2cen]

Are there any possibilities below 0K Dark Matter existence?

 

Normal matter has no fluid behavior at 0K.

But unknown matter which dose not interact with normal matter would have any fluid behavior.

If so, we can use this property to search for Dark Matter.

This is another idea to search Dark Matter.

One required condition is proper Dark Matter concentration.

[ydoaPs]

Exactly. It is, however, close to -0K. There is a funny thing about a system with a negative temperature. Plop it down next to a system with a positive temperature. Heat will flow from the system with negative temperature to the system with positive temperature. The system with a negative temperature is "hotter" than the one with a positive temperature.

 

A couple of lay references:

A recent Science News article: http://www.sciencenews.org/view/generic/id/66435/title/Negative_temperature,_infinitely_hot

Physics FAQ article: http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/neg_temperature.html

So, the answer to 'Can we never[sic] make below 0K?' is still that you cannot reach 0K much less get colder?

[A Tripolation]

So, the answer to 'Can we never[sic] make below 0K?' is still that you cannot reach 0K much less get colder?

 

That's what I'm getting from it. This is incredibly fascinating. I didn't know negative temperatures existed.

[D H]

So, the answer to 'Can we never[sic] make below 0K?' is still that you cannot reach 0K much less get colder?

Assuming that "colder than" means that heat flows from a warmer object to a colder one, that is exactly correct.

[alpha2cen]

heat flows from a warmer object to a colder one, that is exactly correct.

 

Instrument temperature of the infrared space telescope is 0.1K.

So 0K is very cold.

There is no problem using coolant medium.

I don't know 0K problem.

0K scale region is very large?

Below 0K is out of atom area in the Universe?

[D H]

Negative temperatures are not "colder" than 0K, alpha2cen. Your below 0K, meaning colder than absolute zero, is a nonsense proposition.

[alpha2cen]

Negative temperatures are not "colder" than 0K, alpha2cen. Your below 0K, meaning colder than absolute zero, is a nonsense proposition.

 

I mean

At the same atom particles state are changed or separated(proton and neutron separation).

Or, quarks are exchanged or separated.

 

string ------quark ------particle --------atom

.

...................................2 change...........0K

......................................0K..................0K

......................................Heat Q is removed.

Below 0K is no scale

 

Other case

....................................2 change .........2K

.......................................0K.................0K

......................................Heat Q is removed

 

Is this any problem?

Edited December 11, 2010 by alpha2cen

[D H]

Is this any problem?

Yes. What you typed makes no sense. It isn't even nonsense. Try again, without the dots, and more words. What are you trying to say?

 

 

 

[alpha2cen]

Yes. What you typed makes no sense. It isn't even nonsense. Try again, without the dots, and more words. What are you trying to say?

 

 

We can make more low energy state in a particular state.

For example at 0K atomic energy state is very low.

But we can make more low energy state by controling the particular state.

For example

pn------------energy---------------> p + n

low state...............................high state

 

This energy must be absorbed form the surroundings.

 

pn e ----------energy-------------->pn + e

low state...............................high state

Edited December 12, 2010 by alpha2cen

[D H]

For example at 0K atomic energy state is very low.

But we can make more low energy state by controling the particular state.

Nonsense. Absolute zero is absolutely as low as a system can get in terms of energy.