Talk:Unruh effect

message: The existence of Unruh radiation is not universally accepted.  Its status ranges from claims that it has already been observedPhotoluminescence from a gold nanotip as an example of tabletop Unruh-Hawking radiation, to claims that it is not emitted (although the sceptics accept that an accelerating observer thermalises at the Unruh temperature they do not accept that this leads to the emission of real photons. arguing that the emission and absorption rates are balanced in their model and, they claim, probably more generally)Is there Unruh radiation?.
: The controversy about emission is actually an old one--- does a uniformly accelerated charge radiate? The radiation reaction force is proportional to da/dt, so if a is constant, there is no radiation. But boundary effects make a big difference, and so the controversy.
: The Unruh effect itself, though, doesn't care about outgoing photons. It only cares that the detector responds as if in a thermal bath. On that count, the sources you cite don't have any controversy, and as far as I know, nobody else does either. So I think it would be better to make this comment on "radiation reaction", or something.Likebox (talk) 12:14, 30 January 2008 (UTC)
replies: text: Unruh radiation redirects to Unruh effect -- a distinction this section clearly makes -- so it is an issue for this article.  End of story. --Michael C. Price talk 12:26, 30 January 2008 (UTC)
replies: text:  Ok, then I'll put it in, but try to be careful with the distinction.Likebox (talk) 14:48, 30 January 2008 (UTC)
replies: text: I'm clear about the distinction.  Let's make sure about the article.  Thanks for reinserting it.  If the sceptics are right then this has big implications for Hawking radiation... --Michael C. Price talk 21:13, 30 January 2008 (UTC)
replies: text:  I get your drift, but it's just the Unruh effect that's needed for the Hawking radiation, not the Unruh radiation. That's why I wanted to be so careful to make the distinction. You don't need to radiate real photons to infinity in the Rindler case to get the real photons coming out of the black hole. The big difference is that if you redshift in the Rindler metric, the redshift factor goes to 0 as rho->infinity, meaning that by the time you get to infinite rho the equilibrium state is zero temperature. This doesn't mean that Unruh radiation doesn't exist--- I haven't figured that out. I don't know if it does or doesn't I mean. There's other wedges and boundary conditions and I get confused. But in the Hawking case, When you match up the local observer temperature which you know from the local near-horizon Unruh effect to the far-observer temperature by redshifting, the redshift factor asymptotes to a finite value. So if the black hole has a vacuum state which matches to the Unruh vacuum near the horizon, it's got to be hot at infinity, while the Rindler space at infinity is cold no matter what. I'm still confused about the Rindler radiation thing though.Likebox (talk) 22:34, 30 January 2008 (UTC)

text: The article should be written to reflect this (non-violent) controversy. See reflecting controverse below. ... said: Rursus (bork²) 10:51, 20 February 2009 (UTC)
thread_title:  Controversy 

message: Hello, dear webmaster,
I am very interested in the Unruh effect. Can you show me the detail derivation of Unruh effect? Is quantum mechanics needed in the derivation? The article says that accelerated observer will observe temperature. Can I also say that temperature will cause acceleration? I am very curious. Thank you very much.
Sincerely, Wanchung Hu  —Preceding unsigned comment added by Wanchung Hu (talk • contribs) 07:56, 6 November 2008 (UTC)
thread_title:  Complete Derivation of Unruh Effect? 

message: The article starts as be the 'Unruh effect' a scientific truth. Then it walks on gladly, but in the section Experimental Observation of the Unruh effect it suddenly occurs that nobody have observed it! (What a revelation!) The intro should therefore mention 'Unruh effect' as theoretical or hypothetical, and have a final sentence claiming that it hasn't been observed (yet). Furthermore, each mention of 'Unruh effect' should avoid "is", "has" and instead use "would be", "would have" and similar verb forms indicating "hypotheticality" (nice word, ehh ... ?) of the effect. ... said: Rursus (bork²) 11:00, 20 February 2009 (UTC)
replies: text: I got it wrong: truth is that the claimed observations made are under discussion. I'll edit the article according to this. It is still hypothetical. ... said: Rursus (bork²) 11:10, 20 February 2009 (UTC)

text: Now I've made many edits in order to distinguish between the theory of the Unruh effect, that most certainly exists, and the Unruh effect, that may exist. Most of them are in the history marked as "conjunctive", the verb form to use for hypotheses and unattested theories. ... said: Rursus (bork²) 11:19, 20 February 2009 (UTC)

text: The lede labeled the effect as both hypothetical and a prediction which is a bit redundant and somewhat misleading. As the effect (if not the radiation) is expected by everyone, it seems to be more than hypothetical, so I've removed that term. The lede goes on to make it clear that it's not yet observed, so this should cause no misunderstanding. Cutelyaware (talk) 10:12, 14 February 2017 (UTC)
thread_title: Reflecting the controverse properly

message: I have a hard time believing that we really need a Rindler horizon to see Unruh radiation.  The article claims that circular motion does not radiate, because there is no associated horizon, but this claim is not referenced and the only paper supporting it I can find has been withdrawn.--Michael C. Price talk 18:21, 18 April 2009 (UTC)
thread_title: Circular motion and horizons

message: The following paper shows only a transient Unruh effect theory, and not a steady state solution, like a thermometer getting free-energy by accelerating in a vacuum, breaking the conservation law for energy surrounding the thermometer and thrust matter, where it is claimed:
E--Thermometer--System  =  E--Kinetic--Relativistic--Energy  +  Unruh--Vacuum--Energy.
X LoneRubberDragon (talk) 06:21, 16 July 2009 (UTC)
thread_title:  A counter theory paper for references balance. 

message: And as such, the planet will evaporate after all as a black hole does?--MathFacts (talk) 17:21, 10 February 2010 (UTC)
replies: text: I would have thought so, but a number of experts assert the contrary. --Michael C. Price talk 11:11, 8 October 2010 (UTC)
thread_title:  Does the Unruh effect mean any observer on the surface of an atmosphere-less planet would detect radiation? 

message: I propose that the Unruh temperature article should be merged into this article, as it is too short and it would be better on this article. Armbrust Talk Contribs 08:50, 10 September 2010 (UTC)
thread_title:  Merge discussion 

message: Is it possible that the radiation is created by whatever force is maintaining the acceleration of the detector rather than emerging spontaneously from the vacuum? JRSpriggs (talk) 10:41, 8 October 2010 (UTC)
replies: text: I think it amounts to the same thing - i.e. it is a matter of interpretation. --Michael C. Price talk 11:14, 8 October 2010 (UTC)
thread_title:  Is the source of the force and the radiation the same? 

message: I think something should be said on this: http://www.physorg.com/news/2011-07-gyroscope-unexplained-due-inertia.html in the article  — Preceding unsigned comment added by 83.100.194.186 (talk) 08:43, 27 July 2011 (UTC)
thread_title:  Tajmar effect 

message: In the formula for Unruh temperature, derived by William Unruh in 1976, if we insert the minimum temperature of the unverse, i.e. the temperature of cosmic-microwave-radiation 3 degree Kelvin, then the value of acceleration we get from the formula is of the order ten raised to twenty meters per seconds squared. Now, my question is, when the maximum-speed of any object is limited to the speed-of-light, i.e. three-times ten-raised-to-eight meters-pre-second, then how any object can get accelerated to the speed of ten-raised-to-twenty meters-per-second in one second? Some authors have attempted to propose thermodynamic-explanation for gravity, in which they use this Unruh-temperature-explanation to get acceleration of particles, and then compare it with Newton's formula; so if the formula used, to get the value of acceleration, is not correct, then the thermodynamic-explanatin for gravity would loose its base. Therefore, i request the experts to clarify this question. The same question applies to the similar formula for Hawking-Temperature also. Hasmukh K. Tank 123.201.19.157 (talk) 15:17, 23 January 2013 (UTC)
thread_title:  Can the value-of-acceleration be More than the Speed-of-Light? 

message: Some authors have tried to use Unruh effect to derive force from temperature to explain origin of gravity. According to the formula of Unruh-effect, even one degree Kelvin temperature can cause acceleration of the order of ten-raised-to-twenty meters-per-seconds-square. This value is ten-raised-to-twelve-times more than the speed-of-light. How the rate of acceleration can be more than the speed-of-light? So the validity of the formula is questionable. I had put this question in this talk-page which some-one has deleted; which implies that this question is adversely affecting  to some researchers. They should be bold enough human beings to face the questions. Hasmukh K. Tank 123.201.19.157 (talk) 12:44, 24 January 2013 (UTC)
thread_title:  How the Rate Of Acceleration can be More than the Speed Of Light 

message: Just wanted to say thanks after reading this for such a clearly written article.  The understanding it has of the sticking points for lay readers and the simple clarifications it makes eg of a vacuum are greatly appreciated LookingGlass (talk) 17:27, 8 January 2014 (UTC)
thread_title:  Thanks :) 

message: At extremely high energies and close interactions, the components of observer A pass through the components of the observer B. The only observer is the wave function of the universe, thus ANY change has a global impact, which is puny at low energy levels and/or afar interactions especially for some "supposedy" inertial observer. NO INERTIAL OBSERVER actually exists if we are extremely strict (messing a part of the universe messes all other parts, maybe a puny bit, but it messes them).
 WE CANNOT SOLVE THE CONTRIBUTION OF THE UNRUH RADIATION DURING THE BIG BANG IF YOU HIDE ISSUES!
— Preceding unsigned comment added by 2a02:2149:8246:3f00:91c3:5e93:f262:d995 (talk) 03:43, 30 October 2020 (UTC)
thread_title:  You claim: '''The Unruh effect is the prediction that an accelerating observer will observe blackbody radiation where an inertial observer would observe none''' 

message: There are three main hypothesis (nowhere is the fourth)
# everywhere in his/her body
# Imagine the noninertial observer being a point surrounded by a sphere of subluminal expansion around him/her (because we know that the universe expands). According to that view only at his/her causal horizon (where his/her subluminal sphere ends and afar from it the universe expands superluminally in reference  to him/her. Actually for the noninertial observer, we don't have a causal subluminal expansion sphere, but an ovoid (not an ellipsoid). At the front of the causal ovoid (which isn't a sphere because the observer is noninertial) there is more heat than the average void temperature, and at the back less heat than the average void temperature. The overall temperature is the same but biasedly shared according to the distortion of the subluminal causal ovoid. In everyday life, that effect is negligible because most noninertial observers move a lot slower than the speed of light and the universe doesn't explode/expand superluminally in small/near regions. During the Big Bang the Unruh effect isn't negligible, because superluminal expansion happens in very small regions (and not afar galaxies).
# Option two is correct, but option one also but not due to the Unruh effect but because the noninertial body becomes itself slightly distorted in an ovoid-like manner, and that causes two types of heat: 1. negligible internal friction due to the negligible deformation, 2. negligible friction with spacetime itself, because the noninertial observer distorts his mapping of spacetime and thus the energy of the void isn't the same everywhere inside him/her/it but it has a void interpretation bias, and that distortion moves through spacetime (it's not static), and that moving ovoid spatiotemporal distortion causes some negligible friction (which during the Big Bang is ginormous... we have to calculate it...).  — Preceding unsigned comment added by 2A02:2149:8246:3F00:91C3:5E93:F262:D995 (talk) 03:30, 30 October 2020 (UTC)
thread_title:  Controversy over WHERE the accelerating observer detects the radiation 

message: A different virtual sphere of subluminal expansion surrounds each arbitrary observer (a spheres for the inertial observer and an ovoid for the  noninertial).
Problems: Our universe is acceleratingly expanding, thus the size of the "sphere of subluminal expansion" of each observer isn't static in size but its size changes.
If the universe expanded with a constant acceleration, the  sphere of subluminal expansion surrounding each arbitrary observer would have been of fixed size, but that's NOT the case in our universe (Nobel Prize data).
That fact complicates even more the Unruh calculation.— Preceding unsigned comment added by 2a02:2149:8246:3f00:91c3:5e93:f262:d995 (talk) 03:43, 30 October 2020 (UTC)
thread_title:  Secondary problem we didn't mention 

message: Should there not be a 8pi instead of 2pi in the Hawking temperature. If 2pi please show source of derivation, publication for example.
ChrisCalif (talk) 23:34, 21 May 2021 (UTC)
thread_title:  Hawking temperature 

message: This article uses "Last, First" name formats, which  does not do by default. See the documentation for that template, especially the section that reads  – Jonesey95 (talk) 02:29, 3 October 2022 (UTC)
replies: text: Not only that, but articles that don't use cite q shouldn't be converted to use cite q.  Headbomb {t · c · p · b} 02:32, 3 October 2022 (UTC)
replies: text: If the citation's output matches the established citation style in the article, Cite Q should not be a problem. – Jonesey95 (talk) 02:47, 3 October 2022 (UTC)
replies: text: It doesn't, and it makes citation incredibly editor hostile and vulnerable to vandalism.  Headbomb {t · c · p · b} 07:33, 3 October 2022 (UTC)
thread_title:  [[WP:CITEVAR]] and [[Template:Cite Q]]