Image: Photograph by Adam Voorhes
In Brief
- Traditional methods for cooling gases to close to absolute zero work only with a few of the elements.
- Two novel techniques together can cool down atoms of virtually any element, even some molecules.
- One of the techniques, which appears to break the second law of thermodynamics, is a physical realization of a celebrated 1800s thought experiment called Maxwell’s demon.
- Applications range from studying the properties of elementary particles without expensive accelerators to separating isotopes for their use in medicine and research.
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As you read these words, the air’s molecules are zipping around you at 2,000 miles per hour, faster than a speeding bullet, and bombarding you from all sides. Meanwhile the atoms and molecules that make up your body incessantly tumble, vibrate or collide with one another. Nothing in nature is ever perfectly still, and the faster things go, the more energy they carry; the collective energy of atoms and molecules is what we call, and feel as, heat.
Even though total stillness, corresponding to the temperature of absolute zero, is physically impossible, scientists have edged ever closer to that ultimate limit. In such extreme realms, weird quantum effects begin to manifest themselves and to produce new and unusual states of matter. In particular, cooling gaseous clouds of atoms—as opposed to matter in the liquid or solid state—to a small fraction of a degree above absolute zero has enabled researchers to observe matter particles behaving as waves, to create the most precise measuring instruments in history, and to build the most accurate atomic clocks.
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7 Comments
Add CommentIn 2007, Philip Gegenwart at the Max Planck Institute for the Chemistry of Solids discovered an new and unexplained phenomena in the phase transition in an antiferromagnetic metal (Science 315 969) in relation to its quantum critical point. This "dual" universality class has no present physical theory to explain it but it occurs at around 0.8K in compounds like YRS and was descried as a transiton to a "heavy electron liquid" state of matter. Using Raizen's Demon cooling and magnetic field manipulation, I wonder if it might be possible to create a state of matter similar to a BEC in which the normal weak nuclear forces and magnetic repelling forces are redued enough to facilitate fusion of deuterium or tritium with an exothermic release of energy. The implications are obvious.
Reply | Report Abuse | Link to thisPax77...I like your thought about fusing a BEC...maybe this will be the true cold fusion everyone has been looking for....
Reply | Report Abuse | Link to thisSeparation of molecules by type is part of a real method to bypass the second law. Separating molecules requires less work than is gained as a result of the separation.
Reply | Report Abuse | Link to thisIncredibly, instead of using lasers, a more useful version of the method involves mechanically separating steam from air, for example. As steam is separated from air, it condenses, which pumps heat.
The second law does not actually limit separation of molecules by type. The second law only limits extraction of work by gas expansion.
Reply | Report Abuse | Link to thisA simple phenomenon is the temperature Cold. All cells, quarks, nuclei, blood, earth etc produce cold from their poles. We see this on our planet what we don't detect is the cold from the poles of say a skin cell. The ratio of cold emitting from cells is so minute as to go unnoticed except of course the big cell Earth.
Every cell has a nucleus with orbiting bits of itself (nuclei) and individually con zillions of these are in harmony with the cell until a reaction causes the particles to repel one another. Individually these particles have the same energy as the parent two poled cell. Now you will notice the cold being produced.
As an example take an air cell and cause a reaction! OK just blow on your hand.
Man discovered that temperature interacted with mercury and the thermometer was born, I know, I know this is not making sense but hang in there. The house is hot as heck so you have a fan cooling a room. Coming from the hot bathroom it’s refreshing to get back to your cooled room. The thermometer taken from the bathroom reads 40 degrease and now in the cooled room reads 38 degrease. Next day (hot as heck) the bathroom reads a hot 38 and the comfortable room with fan reads 36. OK now this is my discovery. ---
The fan in the room is causing a reaction that has air cells chipping, in other words that one cell that produces cold from its poles is now producing cold from the co zillion poles of it’s chips.
Because Forces of Equal Evolution act Upon Forces of Equal Evolution the cold producing chips or molecules of air do not interact with the mercury of your thermometer. This explains the mystery of wind chill.
cbc.ca bruce voigt
Sounds like the nucleus of a great script for a hit movie!
Reply | Report Abuse | Link to thisThink HOT as being nuclear particals of any cell orbiting in chaotic orbit directions and Cold (blow on your hand) being chaotic nuclear particles orbiting harmonically in same orbit directions.
Reply | Report Abuse | Link to thiscbc.ca bruce voigt
I found the article's explanation of the mysterious role of "information" in the entropy equation somewhat unclear. First it's said that the device "clarifies [...] why Szilard's insight -- that information plays a crucial role -- was correct", and later that "the photon carries away with it information about that atom -- and thus a tiny quantum of entropy."
Reply | Report Abuse | Link to thisHowever, the article then says "Moreover, whereas the original photon was part of an orderly train of photons (the laser beam), the scattered photons go off in random directions. The photons thus become more disordered, and we showed that the corresponding increase in the entropy of the light exactly balanced the entropy reduction of the atoms".
If plain old physical disorder of the photons exactly compensates for the entropy reduction of the atoms, then what is the "crucial role" of "information"?