Timeline for Why do dark objects emit more than lighter ones?
Current License: CC BY-SA 3.0
19 events
| when toggle format | what | by | license | comment | |
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| Apr 13, 2017 at 12:39 | history | edited | CommunityBot |
replaced http://physics.stackexchange.com/ with https://physics.stackexchange.com/
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| Jan 3, 2016 at 2:13 | vote | accept | Dave | ||
| Jan 1, 2016 at 1:35 | answer | added | dmckee --- ex-moderator kitten | timeline score: 6 | |
| Dec 31, 2015 at 16:02 | history | tweeted | twitter.com/StackPhysics/status/682592656745193474 | ||
| Dec 31, 2015 at 4:15 | answer | added | knzhou | timeline score: 5 | |
| Dec 30, 2015 at 21:03 | history | edited | Dave | CC BY-SA 3.0 |
editied for clarity, elaborated on "light" vs "dark" objects
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| Dec 30, 2015 at 20:53 | answer | added | Carl Witthoft | timeline score: 2 | |
| Dec 30, 2015 at 19:54 | comment | added | Luboš Motl | Kevin Ye's or a basically equivalent argument is really the only sensible answer one can get. One could discuss what is happening microscopically. But one would still need to translate the concepts of "black" and "white" to properties of the microscopic building blocks which is rather complicated. And at the end, what one really wants to deduce are just statistical properties referring to absorption and emission of large amounts of light quanta. So one has to use overall thermodynamic properties like the temperature of both bodies, emissivity, absorptivity etc. somewhere in the explanation | |
| Dec 30, 2015 at 19:49 | comment | added | Luboš Motl | Dear @Dave, so you don't mean a "proof vs physical explanation". You mean an "argument using overall macroscopic quantities" vs "argument using microscopic, constructive concepts". You can't really do the latter too well here because "black" and "white" are concepts describing the overall macroscopic appearance of an object, not its microscopic composition, so one must unavoidably use some of the macroscopic arguments that, in your logic, turn an explanation into a "proof". | |
| Dec 30, 2015 at 19:17 | history | edited | ProfRob | CC BY-SA 3.0 |
edited title
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| Dec 30, 2015 at 18:58 | comment | added | Dave | @BowlOfRed Yeeeah, definitely cutting a few corners to keep the question concise but I hope my point comes across. Happy to make edits for clarity if you have a suggestion. | |
| Dec 30, 2015 at 18:56 | comment | added | Dave | @Lubos A proof shows that it is true without explaining the physical interactions that make it true. Neither is better or worse -- they're just different. A different example: A ball bounces. Proof: conservation of energy. Explanation: the elasticity the ball allows it to briefly absorb the kinetic energy of its fall before turning it right back to kinetic energy. | |
| Dec 30, 2015 at 18:37 | comment | added | BowlOfRed | Beware being too simplistic here. Black objects absorb visible light better than a white object does. That does not mean it absorbs or emits more thermal radiation than a white one does. | |
| Dec 30, 2015 at 18:37 | answer | added | Kevin Ye | timeline score: 3 | |
| Dec 30, 2015 at 18:30 | comment | added | Gyro Gearloose | I always had trouble understanding why a ruby is red but also it emits red light when used in a laser. So I would love to see a good answer on this question. | |
| Dec 30, 2015 at 18:27 | comment | added | Luboš Motl | Dave, what is the difference between your "proof" and a "physical explanation"? And if there is a difference, isn't a proof always the "better, safer thing" to have than just a "physical explanation"? | |
| Dec 30, 2015 at 18:27 | comment | added | rodrigo | I always thought that it is that "reverse" explanation: an energy transition is available both to absorb a photon (go from lower to higher energy) or to emit a photon (from higher to lower), the frequency of the photon is the same. | |
| Dec 30, 2015 at 18:24 | comment | added | garyp | Yes, exactly. Same reason in reverse. | |
| Dec 30, 2015 at 18:22 | history | asked | Dave | CC BY-SA 3.0 |