The Unruh Effect
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it as an accessible reference for the Unruh effect, its temperature scaling, and its relation to Hawking radiation and gravitational fields.
Recommended by 0 people across 0 different months, 2018 to 2022.
What it is
A PBS Space Time episode hosted by Matt O'Dowd explaining the Unruh effect: an accelerating observer gets a causal horizon behind them and perceives the vacuum as a warm bath of thermal radiation. It links the idea to Hawking radiation and the equivalence principle, and mentions the extreme accelerations needed to reach even 1 kelvin.
What people said
Cites Yukterez · 2018-10 · Physics Stack Exchange · on “Why is there a flux of radiation in the Hawking effect but not in the Unruh effect? (and other questions)”
But wouldn't that violate the equivalence priciple? Being at rest in a gravitational field should have the same effect as being accelerated in flat spacetime, see Matt O'Dowd's video on the subject: [this video]
Cites Yukterez · 2020-02 · Physics Stack Exchange · on “Does the Unruh Effect violate observer independence in General Relativity?”
@A.V.S. Your downvote is not an argument but only an allegation. I quote [LINK] with *"In the theory of relativity, a constant gravitational field is equivalent to a uniform acceleration"* and Matt O'Dowd at [this video] *"remaining stationary in a gravitational field is equivalent to acceleration in free space; that means you, right now, are bathed in a very tiny amount of Unruh radiation"*, so downvote all you want, it doesn't change that fact - unless of course you can bring some arguments to the table.
Cites Star Alpha · 2021-01 · Physics Stack Exchange · on “What is the formula for relativistic acceleration?”
$BACKGROUND:$ I was recently watching a youtube video about Unruh radiation: [this video] In this video, the host said that we need to accelerate at $10^{20}m/s^2$ to raise the temperature by $1 kelvin$ . This got me thinking about relativistic acceleration because if you accelerate at $10^{20}m/s^2$ , you will pass the speed barrier in less than a second if we apply the math of Newtonian mechanics in which if you are travelling at v and you start accelerating at a then after time t your velocity will be $v+at$ which cannot be true so I want to know the relativistic formula for acceleration. (If you are thinking that how on earth can someone talk about Unruh radiation but don't know the formula f
Cites Rohit Pandey · 2021-09 · Physics Stack Exchange · on “When pressed together enough, matter annihilates with matter?”
Once the blackhole completely evaporates, all the matter that ever fell into it is gone. What happened to that matter? It converted to radiation. Hawking radiation at the horizon is a valid interpretation of this process. However, it isn't the only possible one. Just like the Unrh effect, which is closely related to Hawking radiation has multiple interpretations: [this video] All you did was say "X is not Y" without describing what is wrong with X. We're on the same page with respect to Y.
Critical John Eastmond · 2022-06 · Physics Stack Exchange · on “Does an electric field cause the vacuum to emit photons?”
As I understand it electron-positron pairs pop in and out of the vacuum on a time scale $T$ inversely proportional to the electron mass. Imagine we put a static electric field across the vacuum. Within the time scale $T$ the electron and positron would be pulled apart a little by the electric field before they had a chance to annihilate back into the vacuum. Would the difference between the initial size of the particle pair and the final size lead to a difference in momenta which would then be radiated as a real black body photon? The Fulling–Davies–Unruh effect [LINK] says that a body with acceleration $a$ experiences a vacuum temperature: $$T\sim\frac{\hbar\ a}{c k_B}$$ If we have an elect