Timeline for Quantum death like heat death possible?
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15 events
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| Feb 17, 2011 at 19:12 | comment | added | Marek | @sb1: well, appearance of classical from quantum is about as interesting as appearance of second law from reversible dynamics: not completely settled in every detail but for all practical purposes we know that there's just nothing interesting going on (basically because we can look around and see that macroscopic world obeys both classical laws and second law; even though both of these laws are just approximate). So I still don't see anything interesting in this question. | |
| Feb 17, 2011 at 19:01 | comment | added | Luboš Motl | Dear sb1, if you consider loss of coherence "quantum death", I assure you that 99.99999999999999999999999999999% of the quantum death is completed within a tiny fraction of a second - which may be much shorter than the Planck time for macroscopic objects. In principle, the coherence is always there if you could trace the environment, directly or indirectly, but it's totally inconsequential for physics as an empirical science. The decoherence occurs almost instantly. I still don't understand why you call it "death". It's just the appearance of the classical intuition from quantum mechanics. | |
| Feb 17, 2011 at 18:37 | comment | added | user1355 | @space_cadet: Thanks a lot for understanding the real spirit of the question. The information you have provided is something I have been searching for some time. With a lot of hesitation I dared to ask this question. Thanks again for your guidance. | |
| Feb 17, 2011 at 18:33 | comment | added | user346 | @sb1 your question is a very good one, except the term "quantum death" is not appropriate. You're asking whether decoherence results in the ultimate classicalization of all systems in the universe. The answer is, surprisingly, no. There are such things as noiseless subsystems which are stable quantum systems w.r.t. environmental decoherence. On a somewhat different note you might be interested in Zurek's provocative and beautiful theory of "Quantum Darwinism". Check it out! | |
| Feb 17, 2011 at 18:19 | comment | added | user1355 | @Marek: "already classical (i.e. decoherent)" No, decoherence does not mean classical always. There are many possible histories which have decohered but they do not in the least like our classical world. It is in fact an active area of research to prove that classicality might have emerged from some set of coarse grained histories. | |
| Feb 17, 2011 at 18:12 | comment | added | user1355 | @Marek: Micro physics is still quantum. Right? Characteristic quantum properties are manifest everywhere, isn't it? In the color of objects, structure of crystals, in the electrical, mechanical, chemical properties of different substances and yes in the very phenomena of life itself! | |
| Feb 17, 2011 at 17:55 | comment | added | Marek | @sb1: I think what anna meant is that the (macroscopic) universe is already classical (i.e. decoherent), so the question doesn't really make sense. More interesting question would be whether the correlations would reappear after something like Big Crunch. But in our universe (assuming eternal expansion) there is absolutely no quantum physics at large scales. It's all just GR. Right? | |
| Feb 17, 2011 at 17:23 | history | tweeted | twitter.com/#!/StackPhysics/status/38287419681939456 | ||
| Feb 17, 2011 at 17:18 | answer | added | Lawrence B. Crowell | timeline score: 1 | |
| Feb 17, 2011 at 17:08 | comment | added | user1355 | @George: Quantum death in the sense of complete absence of interference due to decoherence. | |
| Feb 17, 2011 at 17:02 | comment | added | user1355 | @anna v: Are you not aware of this famous paper? link.aps.org/doi/10.1103/PhysRevD.28.2960 | |
| Feb 17, 2011 at 17:00 | comment | added | user1355 | @anna v: Of course there is a wave function of the universe as Hartle and Hawking showed us. Otherwise what do you mean by the subject called "quantum cosmology"? | |
| Feb 17, 2011 at 16:50 | comment | added | anna v | Why would you think the universe will have a "wave function"? In my opinion the universe viewed quantum mechanically has a density matrix composed of all the zillion independent state functions of atoms, molecules, light, etc. It is thermodynamic really. | |
| Feb 17, 2011 at 16:41 | comment | added | Georg | ""Environment acts just like a heat bath"" I doubt that. A heat bath maybe enhances decoherence, but it does a lot more. And why is decoherence of "universe wave function" quantum death? | |
| Feb 17, 2011 at 16:13 | history | asked | user1355 | CC BY-SA 2.5 |