Absolute Zero; 0K

[Fatstep]

How was absolute zero determined, if we cannot achieve it then how did we find it. I've searched endlessly without any results, my AP Chemistry and AP Physics teachers can't explain how they came upon it, so does any one here know?

[Monomer]

Maybe this helps:

 

History of absolute zero

1702–1703: Guillaume Amontons (1663 – 1705) published two papers that credit him with being the first researcher to deduce the existence of a fundamental (thermodynamic) temperature scale featuring an absolute zero. His J-tube thermometers comprised a mercury column that was supported by a fixed mass of air entrapped within the sensing portion of the thermometer. In thermodynamic terms, his thermometers relied upon the volume / temperature relationship of gas under constant pressure. His measurements of the boiling point of water and the melting point of ice showed that regardless of the mass of air trapped inside his thermometers or the weight of mercury the air was supporting, the reduction in air volume at the ice point was always the same ratio. This observation lead him to posit that a sufficient reduction in temperature would reduce the air volume to zero. In fact, his calculations projected that absolute zero was equivalent to −240 degrees on today’s Celsius scale—only 33.15 degrees short of the true value of −273.15 °C.

 

Found at:

absolute zero: Definition and Much More from Answers.com

[Fatstep]

Thanks.

[HydrogenBond]

What is interesting is that absolute zero and the speed of light are two absolute constants, that do not change, can't be exceeded, and are both relatively small finite numbers. They have a connection to each other since, absolute zero is a place void of energy.

 

It is currently assumed there is one last vibration at absolute zero, but since absolute zero has never been reached, this final state is more like absolute zero+. With no energy at absolute zero, that is the only situation in nature where the speed of light is not valid, since there is no energy to generate the speed of light. Only stationary matter will exist.

[Fatstep]

What is interesting is that absolute zero and the speed of light are two absolute constants, that do not change, can't be exceeded, and are both relatively small finite numbers. They have a connection to each other since, absolute zero is a place void of energy.

 

It is currently assumed there is one last vibration at absolute zero, but since absolute zero has never been reached, this final state is more like absolute zero+. With no energy at absolute zero, that is the only situation in nature where the speed of light is not valid, since there is no energy to generate the speed of light. Only stationary matter will exist.

 

So, if an object were able to be frozen at 0k would it just fall into a pile of electrons, neutrons, and protons?

[ronthepon]

So, if an object were able to be frozen at 0k would it just fall into a pile of electrons, neutrons, and protons?

That is a question I've been raring to ask, just worded differently.

 

Will the electrons continue to remain in motion around the nuclei? And if they are totally stationary anyway, then won't they violate the uncertainity principle?

[kmcolo]

It is all theoretical since absolute zero is not achievable. Thus to that end...

 

Since E=mc^2 there are two theoretical ways to get to absolute zero (system E equal to 0) and that would be for the mass to completely go to zero or for the speed of light in a vacuum to go to zero. So given that one can not change the speed of light in a vacuum then I would assume that, once absolute zero is reached, the matter would cease to exist.

 

Thus even though one could theoretically get cold enough to prevent all movement of the particles, that the particles have mass at all would require the system to have energy and thus absolute zero would not be achieved.

 

Absolute zero is different than the speed of light in that the speed of light is achievable (light does it all the time) while absolute zero is not. One could think of an equivalent to absolute zero which one could call absolute speed which would be an infinitesimally small fraction faster than the speed of light.

[HydrogenBond]

At absolute zero, there is no energy, so if the speed of light continues to exist, it has to occur without energy. At absolute zero we may have to call C the speed of X, which goes at C.

 

Another thing that would have to occur is that force would have to disappear. As long as there is force there is potential energy in that force. With energy equal to zero, force potential would be zero. That would preclude matter as we know it, since mass or charge would result in force potential still existing. Even the potential that binds these composite particles will dusappear. The net result would be only particles x moving at the speed of light (X) without mass, charge or force.

 

Particle X is analogous to infinite wavelength energy. This is actually a misnomer. The phenomena energy has the property of wavelength time frequency equals C. Since there is no number times infinity that will equal C, this mathematically discontinuity is not energy. But it moves at C (why it is referred to as infinite wavelength energy) but without its wavelength times frequency equal to C. It is not part of temperature.

[LJP07]

It is all theoretical since absolute zero is not achievable.

 

My thoughts exactly. But even if it violates Heisenbergs what is stopping it being true, how do we know that it cannot be reached at all, like you said if the Speed of Light could be a minute amount more, why can't a minute amount extra be reached as it's easier to get extra than to exceed a supposed limit?

[CraigD]

When discussing temperature, it’s critical to define it precisely. The usual definition is: “temperature is the average kinetic energy of the molecules in a collection of molecules”. This definition is inadequate to describe very important temperatures, such as the average 2.725° K temperature of the vacuum in the universe. For this, we must include the total energy of massless particles, mostly photons, and a more complicated definition: “the temperature (per the usual definition) of a collection of molecules exposed to that vacuum”.

 

Combining the two definitions leads to one that considers the kinetic energy of massive particles (such as protons, neutrons, and electrons), and the massless ones (such as photons) that can interact with them. Note, importantly, that although other particles (such as gluons) interact with massive particles (such as the quarks that comprise nucleons), and even have significant relativistic mass themselves (According to the standard model, about 99% of the mass of protons and neutrons consist of relativistic gluons!), it isn’t sensible to consider them in a definition of temperature other than as contributing to the mass term of the kinetic energy of protons and neutrons, because they can’t be measured in any macroscopically sensible way.

 

This definition can be simplified at the expense of some explicative value, as the same as the definition of the temperature of vacuum: “the temperature (per the usual definition) of a collection of molecules of the same density and composition of the surrounding space”, or, simplified a bit more “whatever a thermometer says it is”.

Will the electrons continue to remain in motion around the nuclei [of an atom at 0° K]?

I believe so.

 

As the temperature of a collection of atoms approaches 0° K, all of its electrons will fill their lowest orbitals. When this discrete event occurs, the electrons will no longer be able to emit photons of EM radiation. If the relative velocities of the atoms are zero, the interaction of the electrons and nucleons via virtual photons of magnetic interaction, while still virtually existing, will carry no energy among them. AFAIK, the quantum wave functions of all these particles would not suddenly change, so a classical description of the electrons would be that they are still in their lowest orbitals. As no measurement of them could be made without interacting via a photon or other boson, we might argue that it makes no sense to describe them as “moving”, but, if we adds energy in the form of photons (causing it’s temperature to exceed 0° K), we can make measurements of the positions of its electrons, discovering them to still be “orbiting” their nuclei.

It is all theoretical since absolute zero is not achievable.

As I hope my previous exposition explains, whether absolute zero is achievable or not depends on how we define it.

 

By the one I gave above, 0° K is achievable. By other definitions, it’s not. The key question, IMHO, is how useful ones definition is, for the question at hand. In other words, even absolute temperature is not absolute ;) – it’s relative to its definition.

Since E=mc^2 there are two theoretical ways to get to absolute zero (system E equal to 0) and that would be for the mass to completely go to zero or for the speed of light in a vacuum to go to zero.

I believe this statement confuses the concept of temperature, and that of total mass/energy. No useful definition of temperature of which I’m aware equates it with total mass/energy, which is nearly a factor of 10^9 greater (per unit mass, the heat energy of the universe is about .25 eV/AMU, or 2.4*10^7 J/kg, while its total energy, given by the familiar [math]E=Mc^2[/math] matter energy equivalency, is about 9*10^16 J/kg)

[kmcolo]

I believe this statement confuses the concept of temperature, and that of total mass/energy. No useful definition of temperature of which I’m aware equates it with total mass/energy, which is nearly a factor of 10^9 greater (per unit mass, the heat energy of the universe is about .25 eV/AMU, or 2.4*10^7 J/kg, while its total energy, given by the familiar [math]E=Mc^2[/math] matter energy equivalency, is about 9*10^16 J/kg)

 

You're right, it does.

 

Ken

[silverslith]

Is it bose-einstein condensates that lightspeed~10 m/s has been measured in near absolute zero. Something about the particle nature of the atoms dissapearing and the wavefunctions merging. A while since I read about that. Speculation that you could recondense it into any collection of atoms.

[Erasmus00]

At absolute zero, there is no energy, so if the speed of light continues to exist, it has to occur without energy. At absolute zero we may have to call C the speed of X, which goes at C.

 

Another thing that would have to occur is that force would have to disappear. As long as there is force there is potential energy in that force. With energy equal to zero, force potential would be zero. That would preclude matter as we know it, since mass or charge would result in force potential still existing. Even the potential that binds these composite particles will dusappear. The net result would be only particles x moving at the speed of light (X) without mass, charge or force.

 

Particle X is analogous to infinite wavelength energy. This is actually a misnomer. The phenomena energy has the property of wavelength time frequency equals C. Since there is no number times infinity that will equal C, this mathematically discontinuity is not energy. But it moves at C (why it is referred to as infinite wavelength energy) but without its wavelength times frequency equal to C. It is not part of temperature.

 

 

This, like most of your physics related ramblings, is mostly nonsense. At absolute zero all particles drop to their ground state, they do not have exactly 0 energy. Entropy does drop to 0, since there is quite a lot of order (everything is in its ground state). However, particles may have both potential and kinetic energy. The energy of the harmonic oscillator, for instance, is non-zero in its ground state.

 

Next, you say "phenomena energy has the property of wavelength times frequency equals C." More correctly, you would say this is a property of electromagnetic waves. There are many forms of "traveling energy" for which this is not true. Consider, for instance, waves in water or air.

-Will

[Titas Aduksus]

Ah!

 

That's all very interesting, maybe (tongue in cheek) at absolute zero matter simply ceases to exist and the expansion of the universe is the creation of space as temperature expands (if you see what I mean) - from that there may a point where temperature has a planck value so the universe might dissappear when entropy takes it's temp below 1 'planck' degree. Or maybe those two glasses of whiskey are begining to take effect.... Now I'll just duck while you all respond...

[kmcolo]

Ah!

 

That's all very interesting, maybe (tongue in cheek) at absolute zero matter simply ceases to exist and the expansion of the universe is the creation of space as temperature expands (if you see what I mean) - from that there may a point where temperature has a planck value so the universe might dissappear when entropy takes it's temp below 1 'planck' degree. Or maybe those two glasses of whiskey are begining to take effect.... Now I'll just duck while you all respond...

 

What the h?

 

I think you're on to something (like the next glass!). Or is that on something? I like the idea of temperature expansion. My only question, is it degrees planck or just planck, as in 1 planck?