Hawking Definition and 326 Threads

I know that entropy is a measure of disorder. But Entropy is also a function of the state of a system, and has a value determined by the state variables of the system. Does that mean Entropy describes the equilibrium state of a system. Please explain in layman terms in this context what is...

Black holes are claimed to radiate at a temperature corresponding to the hawking radiation. But who is measuring the temperature? If the radiation is measured from far away the red shift will indicate a lower temperature won't it? Is the temperature given by the formula as measured from a...

I see that the formula for hawking radiation is related the the formula for unruh radiation. The accelleration experienced by a body yields an unruh temperature equivalent to a black holes hawking temperature with an equivalent value of g. The unruh effect happens at all accelerations, therefore...

Something I don't understand is how the energy is subtracted from the black hole. So let's say one pair of virtual particles pop up on the event horizon, the particle goes in, the antiparticle goes out. Then let's say that a second pair does the opposite. My first question is why is the...

I am at odds over how Hawking Radiation can cause a problem with entanglement - or even how the pair particle to a Hawking particle can enter a black hole. The notion behind Hawking Radiation, as I understand it, is that a particle divides above the event horizon creating two entangled...

I just saw The Theory of Everything, which is a Hollywood biopic about Stephen Hawking. Of course the physics content had to be watered down and made to serve dramatic and thematic purposes, but a couple of historical points seemed interesting and made me wonder whether they were real: 1...

Simple questions. There is a formula for the POWER of Hawking radiation, but what's about it's spectrum? What is the shape of the power/wavelength curve?

If you only knew the temperature of the black hole, like, if for example, the temperature of a 4 solar mass black hole being around 1.5e-8 kelvin, how could you possibly be able to calculate what wavelengths of radiation the black hole would give off? Would a black hole like this really only...

Ok, I admit i am comparing apples to oranges - cosmologist to engineer. But if you were to choose one based on intelligence, who would it be? If you regard neither of these two men as the most intelligent man who has ever lived, who do you regard as such?

I was reading "Black Holes and Time Warps" by Kip Thorne, and right around p.442-443 it talks about how the quantum vacuum fluctuations that give rise to Hawking radiation from an infalling frame of reference give rise to an "atmosphere" of real, non-virtual particles in an accelerated frame...

Wow! Thanks to all for this great resource. Would it be possible to cast light harmlessly by spontaneously creating microscopic black holes of small enough mass? Or would you necessarily get high-frequency X and gamma radiation along with visible light?

I'm trying to understand the ideas in this paper at a nontechnical level: Laura Mersini-Houghton, "Backreaction of Hawking Radiation on a Gravitationally Collapsing Star I: Black Holes?," http://arxiv.org/abs/1406.1525 She says: This work investigates the backreaction of Hawking radiation on...

The way I understand Hawking radiation is that black holes decay by sucking in anti particles from the virtual particle pairs that are created right at its event horizon. I also understand that these anti particles reduce the mass of the black hole instantly when crossing the event horizon? And...

I previously posted on the idea that the Hawking equations looked wrong: https://www.physicsforums.com/showthread.php?t=666962 I returned to this topic recently, and noticed something. If you multiply power by time, you should get energy. Multiplying the Hawking power by the evaporation...

Video: http://pirsa.org/14070019 Asymmetric Hawking Radiation: Baryogenesis from Hawking Radiation Anson Hook Abstract: We show that in the presence of a chemical potential, black hole evaporation generates baryon number. If the inflaton or Ricci scalar is derivatively coupled to the B-L...

[SIZE="4"]Definition/Summary Hawking radiation is black body thermal radiation predicted to be emitted by black holes due to quantum effects- 'The vacuum in quantum field theory is not really empty; it's filled with "virtual pairs" of particles and antiparticles that pop in and out of...

So we are at a distance from the black hole R>2GM/c^2 where quantum fluctuations happen all the time. How is it possible that every time the anti-particle ends up in the black hole(the one that will decrease her mass) and eaven if it's so,how can the other particle escape?if they are at a really...

Hello guys. From my understanding of the Hawking radiation, it is a consequence of QFT in curved space time. The fact that a uniformly accelerated observer sees the Unruh radiation means that by the equivalence principle, a stationary observer at a distance from a black hole will see Hawking...

So as I understand it, Hawking theorized that due to the behaviour of virtual particles on the event horizon of a black hole, eventually the black hole would "evaporate" through what was coined the Hawking Radiation. But what I'm curious about is Hawking's interpretation of the event in that...

THAT'S AN EXTREMELY HILARIOUS INTERVIEW WITH STEPHEN HAWKING. What are your thoughts on it? https://www.youtube.com/watch?v=OPV3D7f3bHY

What is stability of Hawking Mass and how to calculate it? Any references will be appreciated. Thanks

Hello all, I will freely admit I suffer from Obsessive Compulsive Disorder, and now that it is well managed I tend to attach my obsessions over interest. One thing I tend to obsess about is the possibility of aliens. I think about the fact that us humans are the only technological creatures on...

Here is my understanding, please correct me if I made any mistake Quantum physics theory suggests that information (the wave function, state, etc.) cannot be destroyed. All matters fall into a black hole will not be able to escape, which means all information of these particles stay inside...

Hawking Radiation and the "Decay" of Black Holes I have been doing a lot of reading and thinking about certain quantum mechanics so that I can try and wrap my head around how it all works. However I have come upon something that I cannot find a good explanation for. I was reading about...

Does the existence of observer dependent particles as predicted by the Unruh effect and Hawking radiation lead to paradoxes?

say you measured every particle which has entered a black hole say you measured every hawking radiation particle which exits the black hole my understanding is that if like... a proton enters the black hole, then an anti-proton needs to be emitted via hawking radiation. so if you measure...

From what I understand, Hawking radiation results when one virtual particle (of the pair) falls into the black hole while the other escapes... See I understand why the virtual particles don't come back together - because one is created beyond the horizon while the other is not. But how...

Hawking Says, "There are no black holes." More: http://www.nature.com/news/stephen-hawking-there-are-no-black-holes-1.14583

So as I understand it Stephen Hawking and one other person I can't remember the name of worked on an equation to described the "temperature" of a black hole, that you can actually get information out of it. I know that there is one way it could happen with those vacuum particles in vacuum energy...

Hello All, I have been trying to understand the exact contribution of our legendary physicist, Dr.Hawking and found that Hawking radiation is amongst one. Is it that Hawking radiation is the first attempt to unify, general relativity, quantum mechanics and thermodynamics which led to the...

Hi all, to begin this is my understanding of hawking radiation. A particle/anti-particle pair is generated. one particle outside the event horizon of a black hole, the other inside. The gravitational force "boosts" the one particle into being real. this energy is compensated for by endowing...

Hi all, I was wondering if, when a beam of light is pulled towards a black hole , because it can't accelerate, it is blueshifted? Thanks in advance.

The hypothetical Hawking radiation means that a set of baryons can be finally transformed, "evaporate" into a massless radiation - that baryons can be destroyed. It requires that this matter was initially compressed into a black hole. If baryons can be destroyed in such extreme conditions, the...

Homework Statement Metric signature: - + + + Schwarzschild metric: dS^{2}=-(1-\frac{2M}{r})dt^{2}+(1-\frac{2M}{r})^{-1}dr^{2}+r^{2}d\theta^{2}+r^{2}(sin\theta)^{2}d\phi^{2} Second fundamental form: h_{ij}=g_{kl}\Gamma^{k}_{ij}n^{l} where: i=1,2 j=1,2...

Hi, I've tried several times to get my head around this, but every way I look at it Hawking Radiation doesn't seem to fix the thermodynamic issues it was supposed to solve. People who are a lot smarter than me seem to believe it's real, so can someone please point out where I'm going wrong...

I was wondering whether anyone could provide an explanation as to why when two particles are created near the event horizon, only the negative energy particle is captured by the black hole, and the positive particle travels outward and is seen as Hawking Radiation. I have read numerous posts...

The solution of Einstein's field equations for a simple black hole show a slowing of time as you get close to the black hole. Time stops at the event horizon. An observer in flat spacetime far from the hole would see an astronaut fall slower and slower as he approaches the event horizon. It...

http://news.cnet.com/8301-11386_3-57579003-76/stephen-hawking-predicts-end-of-earth-scenario/

Hello all . I can not explain good but hope you will understand my purpose . I read in University Oregon's website that universe came from a pure energy in vacuum If we want to say exactly , we can say universe came from Potential energy in vacuum . We know in physics there are some...

When the 'evaporation' of a black hole supposedly occurs, it is always attributed to 'Hawking radiation.' As I understand it, Hawking radiation occurs when a virtual particle pair is 'split' at the exact edge of an event horizon. When this occurs, one of the particle pair escapes to 'normal'...

Hi, my first thread. The Hawking temperature for a BH can be derived through compactifying the timelike dimension and hence identifying the time coordinate of the euclidean metric such as a periodic coordinate τ with period β. Now, very interestingly in the context of AdS/CFT correspondence...

Hawking's equations for black hole energy, power, and evaporation time are unattractive. http://en.wikipedia.org/wiki/Hawking_radiation The energy equation, with its denominator of 8 pi GM, isn't too bad, but it has already been challenged as being off by a factor of two. See arxiv, "Black...

Hi. If the hawking radiation is emitted from outside the event horizon , because probably that's the last place where the particles are being able to escape, then how come huge black holes ever evaporate as the matter behind event horizon has no chance of escaping in any way as to the immense...

Can Stephen Hawking really claim that there was no time at all before the Big Bang when a black hole can have an outside observer on normal time? And what about other Universes in relation to our Universe? Don't they have a normal time at the time of our Big Bang?

Why is it that the smaller a black hole is, the more Hawking radiation it emits? It seems counterintuitive to me. I would think that a larger black hole with a larger surface area would trap more antiparticles from virtual particle antiparticle pairs, hence emitting more Hawking radiation.

Discussions involving Hawking radiation in the study of black holes usually require their preexistence; however, if we apply the Hawking radiation process to the initial stages of a birthing black hole I'm confused about how the theory claims the event horizon would form in the first place. In...

I just finished watching a few Stephen Hawking specials. I watched "Did God create the universe" and the one about black holes. I am by far not even close to knowing anything about Astrophysics, so please forgive my ignorance. I just found the shows interesting and have a few questions...

As I understand it, as a particle is observed approaching an event horizon, will would never be observed to cross the horizon, and it's red shift would tend towards infinity. I've read conflicting things about this, A, that that red shift WOULD NOT reach infinity in a finite time, and B, that...

I've seen it said somewhere that an observer falling into a black hole doesn't notice anything qualitatively unique at the exact moment they cross the event horizon. Does this include Hawking radiation? That radiation is described as being emitted by the event horizon, so once the observer...

Hi all, I am trying to understand the process of Hawking radiation in the case of an eternal (static/everlasting) black hole. As a bit of background: i understand (semi-quantitatively) how one gets particles produced when one is a frame with constant acceleration. And I sort of understand...