Re: Re: [humanism-174] Re: Below Zero K.?

From: Randy P.
Sent on: Sunday, January 6, 2013 10:12 PM
This excerpt from an article at Science Daily, an online science news service, might help in understanding this phenomenon. Here is the link to the full article:

The first paragraph is the the most relevant in addressing the question of how there can be negative energy.


"A negative temperature can only be achieved with an upper limit for the energy
The meaning of a negative absolute temperature can best be illustrated with rolling spheres in a hilly landscape, where the valleys stand for a low potential energy and the hills for a high one. The faster the spheres move, the higher their kinetic energy as well: if one starts at positive temperatures and increases the total energy of the spheres by heating them up, the spheres will increasingly spread into regions of high energy. If it were possible to heat the spheres to infinite temperature, there would be an equal probability of finding them at any point in the landscape, irrespective of the potential energy. If one could now add even more energy and thereby heat the spheres even further, they would preferably gather at high-energy states and would be even hotter than at infinite temperature. The Boltzmann distribution would be inverted, and the temperature therefore negative. At first sight it may sound strange that a negative absolute temperature is hotter than a positive one. This is simply a consequence of the historic definition of absolute temperature, however; if it were defined differently, this apparent contradiction would not exist.

This inversion of the population of energy states is not possible in water or any other natural system as the system would need to absorb an infinite amount of energy – an impossible feat! However, if the particles possess an upper limit for their energy, such as the top of the hill in the potential energy landscape, the situation will be completely different. The researchers in Immanuel Bloch’s and Ulrich Schneider’s research group have now realised such a system of an atomic gas with an upper energy limit in their laboratory, following theoretical proposals by Allard Mosk and Achim Rosch.
In their experiment, the scientists first cool around a hundred thousand atoms in a vacuum chamber to a positive temperature of a few billionths of a Kelvin and capture them in optical traps made of laser beams. The surrounding ultrahigh vacuum guarantees that the atoms are perfectly thermally insulated from the environment. The laser beams create a so-called optical lattice, in which the atoms are arranged regularly at lattice sites. In this lattice, the atoms can still move from site to site via the tunnel effect, yet their kinetic energy has an upper limit and therefore possesses the required upper energy limit. Temperature, however, relates not only to kinetic energy, but to the total energy of the particles, which in this case includes interaction and potential energy. The system of the Munich and Garching researchers also sets a limit to both of these. The physicists then take the atoms to this upper boundary of the total energy – thus realising a negative temperature, at minus a few billionths of a kelvin."

From: Glen <[address removed]>
To: [address removed]
Sent: Sunday, January 6,[masked]:51 AM
Subject: Re: Re: [humanism-174] Re: Below Zero K.?

Tim wrote,
"Beyond my paygrade, but I get from the article that the state of absolute
zero does not mean that ALL atoms are motionless, but that they average.
Thus some atoms are in motion with postive energy while others are giving off
negative energy. If they average zero, then you have absolute zero even though some of those atoms are still moving!  I am not sure how this works

I'm sorry, but I don't see how one can have "negative energy." That still implies less energy than no energy, regardless of how many atoms are involved.  As I asked  Recently we were talking about the difficulty of wrapping our minds around the concept of nothingness, and how something can come from nothing (not just an vacuum with energy, but truly nothing). Now we're asked to accept the possibility of having a property of essentially less than nothing--that is, less than no energy.  Really? Am I the only one here who has trouble with this concept?  To me it makes as much sense as saying, I had 5 marbles, and lost 6 of them, so now I have less than no marbles. If I keep thinking about this stuff, that's where I'm afraid I will end up.

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