Timeline for Is temperature in vacuum zero?
Current License: CC BY-SA 2.5
12 events
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| Dec 20, 2010 at 8:46 | comment | added | user68 | @Marek This make some sense; judging from the accepted answer this is also what OP wanted to get. | |
| Dec 20, 2010 at 0:55 | comment | added | Omega Centauri | mbq: I thought I was claiming the temp should be defined to be the temperature of the walls, that would be a radiation temp, and if there were any particles, they would also have the same value. So I think we do agree. | |
| Dec 19, 2010 at 19:54 | comment | added | Marek | @mbq: I see, you interpreted the question differently. I've understood the question as a conceptual one. It doesn't talk about precise physics of the box, quantum fluctuations of vacuum or any other real physics; just classical point particles (or elastic balls). That's why I think your answer misses the point. | |
| Dec 19, 2010 at 18:08 | comment | added | user68 | @Omega, @Sklivvz, @Marek I'm happy that you agree, but I don't understand what is your problem; IMO TMC asked if there can be a temperature in absence of gas particles and the answer to this question is yes. | |
| Dec 19, 2010 at 15:54 | comment | added | Omega Centauri | Agreed with Sklivvz: Assuming the walls are at a uniform temperature, we will see a plank distribution of EM energy. This distribution defines the temperature of the radiation field. Unless this wall temperature is absolute zero, you can't have a perfect vacuum, because there would still be photons. There would also be a few gas particles, as the vapour pressure of any material will be nonzero at any finite temperature, and evaporation and deposition of gas particles would reach an equilibrium. | |
| Dec 19, 2010 at 14:41 | comment | added | Marek | @mbq: I agree with @Sklivvz. Actually he is getting at the core of the problem with measurement of temperature. We can imagine universe where there would be two completely independent interactions (like EM and weak, but imagine weak is isomorphic to EM). Now if we have thermometer that is based on EM radiation it will show EM temperature and if it is based on "weak" interaction it will only detect "weak" temperature. These two temperatures can be arbitrarily different. Similar phenomenon happens between conductive vs. radiative heat transfer. | |
| Dec 19, 2010 at 14:21 | comment | added | Sklivvz | @mbq, I believe a thermometer will show something similar to the temperature of the borders even if we have a non zero, but very small, number of particles - for which the temperature might be different (in the Boltzmann sense), so a thermometer can't be used to determine the temperature in this case. I think. | |
| Dec 19, 2010 at 14:11 | history | edited | user68 | CC BY-SA 2.5 |
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| Dec 19, 2010 at 14:11 | comment | added | user68 | @Sklivvz damn phone typing correction; I'll edit this. But I don't agree that this doesn't answer question; it is explicitly mentioned that this is about vacuum in a box. | |
| Dec 19, 2010 at 14:02 | comment | added | Sklivvz | Correct, but not answering the question (and a thermostat does not show any temperature ;-) | |
| Dec 19, 2010 at 13:51 | history | edited | user68 | CC BY-SA 2.5 |
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| Dec 19, 2010 at 13:41 | history | answered | user68 | CC BY-SA 2.5 |