Hawking Definition and 329 Threads

Hello, I am a bit confused on the relation between the Hawking effect(radiation) and the Unruh effect. What I understood with my little knowledge is that the Hawking temperature is the temperature that is emitted at the event horizon of a black hole as measured by an observer at infinite spatial...

I have come across the following multi-explanations of how Hawking radiation/evaporation of a black hole happens: Particle/anti-particle story: particle/antiparticle pair creation from vacuum near the event get torn apart - one going into black hole, the other away; in some of these...

In Hawking-Ellis Book(1973) "The large scale structure of space-time" p69-p70, they derive the energy-momentum tensor for perfect fluid by lagrangian formulation. They imply if ##D## is a sufficiently small compact region, one can represent a congruence by a diffeomorphism ##\gamma: [a,b]\times...

Recently I was actually stuck on a thought about hawing radiation. If quantum fluctuations cause virtual particles to occur from space. So, to maintain the balance of mass in the universe, the particle with -ve energy should be having -ve mass, right? If so, by Newton's equation of gravitation...

I was thinking about the title but after searching Arxiv, PF and the internet in general, my confusion has only increased. I have a few questions: 1. Often I see units where ##G=c=\hbar=1##, but what is the charge of an electron in these units? Everyone says M=Q as if it was somehow obvious how...

When reading about this subject on the internet, I found two ways how it works and I don't know which one is correct. 1: A particle pair is created near the black hole horizon. So there is an antiparticle and a particle. The antiparticle gets sucked into the black hole but because the...

Homework Statement For school I'm doing a project on hawking radiaton but I have very big difficulties trying to understand it. I'm trying to understand the matter about: Unruh effect, particle pair (antimatter - matter) and the theory of relativity regarding vaccuum. Homework Equations none...

I am an undergraduate student of a university, I have taken the research topic as Study of Rotating black holes and Hawking radiation which I am really interested. Research description as follows. The geometric invariant are computed in various black hole geometries in several different...

Hello everyone! Im a newcomer, a teenager who has countless doubts with respect to relativity, quantum theory etc. But these two questions bother me the most: 1) Hawking radiation states that when the separation of a particle (eg. a photon) into charged particles happens in the event horizon...

The following are a few questions to help me understand the variability of views about Hawking radiation held by various knowledgeable PF QM physicists. 1. Do you personally believe that Hawking radiation is a real phenomenon rather than a only a theoretical possibility? 2. What percentage of...

Hello, I am rather new to Physics and for a class project on exponential growth and decay in nature and I chose the effects Hawking Radiation on black holes. If anyone could help explain how the mass and temperature change over time and how to calculate them(this one especially) that would be...

can string theory reproduce hawking radiation in non-extremel black holes in 4D? i.e physically realistic black holes. do they exactly match hawking's calculations? what is the interpretation of hawking radiation in string theory?

TheAdmin submitted a new PF Insights post Think You Know Stephen Hawking Continue reading the Original PF Insights Post.

One way that people introduce the Hawking temperature of an event horizon, is by taking the near-horizon limit of the BH metric and then do a Wick rotation of the time coordinate. Then, the regularity of the metric requires that the Euclidean time to be periodic. But how can this give us the...

Could this possibly be what the inside of a black hole looks like? aka our Universe resides in a black hole and this area is the event horizon slowly becoming more desolate as Hawking radiation occurs on the opposite side.

I thought Hawking radiation was a virtual particle pair emerging from nothing, one particle falling into the event horizon and the other particle tunneling out of the event horizon. Then I read this - https://www.physicsforums.com/insights/vacuum-fluctuation-myth/ and now I think a virtual...

I'm reading this article... "Hawking proposed that the Universe is filled with 'virtual particles' that, according to what we know about how quantum mechanics works, blink in and out of existence and annihilate each other as soon as they come in contact - except if they happen to appear on...

First, what are these 'particles' that appear with their negative mass counterpart and suddenly disappear very quickly and why do they do that? Now, I know the positive mass ones are allowed to escape the event horizon while the negative mass doesn't, thus fall into the black hole, but how does...

So hawking radiation is a phenomenon thwt happens when a pair of particle-anti particle are generated from vacuum according to Heisenberg uncertainty principle at the horizon of e event is that right? And the negative particle "falls" into the black hole while the positive one escapes as hawking...

Usually Hawking radiation is treated from the point of view of an observer outside the black hole (by which I mean the event horizon, not the supposed singularity), in which case it is possible (although maybe not convenient) to treat the black hole as not having an interior. However, let us...

Does anybody know where I can find a walkthrough of the derivation of Black hole entropy the way hawking did it? (I'm not worried about deriving from string theory or lqg) I'm looking to follow along to understand the assumptions in the derivation.

Where can I find a free digital copy of The Large Scale Structure of Space-time by Hawking and Ellis?

In my Part I post https://www.physicsforums.com/threads/qs-re-hawking-radiation-part-i.873163/reply?quote=5482437 I asked if there were any errors in my summary description of the Hawking radiation phenomenon. So far none have been posted. In this thread I want to learn some additional facts...

I am starting this thread to continue asking questions regarding the Hawking Radiation phenomenon which were discussed in the Comments thread about the Insights article “Misconceptions about Virtual Particles”. This discussion has been mostly a dialogue between A. Neumaier and myself starting...

A black hole evaporates through hawking radiation, what I don't get is the requirement for an energy-negative energy pair production. Since it's the black hole's gravitational energy that's responsible for the pair production, even if one of them escapes, the black hole would lose energy anyway...

I was playing around with numbers and found that the equivalent temperature for Hawking radiation from a Planck mass black hole is ~5×1030 K. Later, I saw that the Hagedorn temperature for strings (where the partition function is expected to diverge) is reported to be around ~1030 K. I thought...

Dear PF Forum, I'm trying to make sense about Hawking radiation in Black Hole. And that leads me into entropy. I read this equation in https://en.wikipedia.org/wiki/Entropy What does that mean? S is the change of Entropy What does Qrev mean there? Is it in Calorie? then Joule? T, I think is in...

The question is to resolve a logical conflict. GR says as we fall into a black hole, an outside observer will see that event come to a stand still as if the falling object is hovering at the horizon. This stand still extends to infinite time. Unfortunately, I've read and hear the term...

After reading Hawking's Grand Design I'm curious about what appears to be an inconsistency in his reasoning. His basis for the multiverse is that every permutation of M-Theory corresponds to different physical laws and that every possible history is relevant for predicting the state of a...

Is there a limit as to how much a black hole gathers mass and how much it losses mass via hawking radiation so that the black hole becomes in equilibrium, neither gaining mass or loosing mass How long would it take a hypothetical isolated black hole to loose one solar mass due to Hawking radiation.

Why is it that the smaller the black hole is, the more quickly it supposedly evaporates? It seems like a black hole should radiate energy proportional to the surface area of the event horizon. To me it seems like the evaporation should slow down the more the black hole shrinks because the energy...

Since Schwarzschild solution describes exterior not only of black holes, but of any spherically symmetric non-rotating objects, then any such object should emit Hawking radiation, no? Then how exactly is that working? Let's set up a thought experiment. Say, we construct a spherically symmetric...

have read numerous times about Hawking radiation. don't understand how that can lead to black hole evaporation in so much that wouldn't as many matter as anti-matter particles fall in thus balancing out over time to the growth and evaporation of black holes thus leaving the mass of the balck...

[Mentor's note: Moved out from another thread where it was a bit of a digression] "Yeah, well, there are some people who spend an awful lot of time talking about the interpretation of quantum mechanics. My attitude -- I would paraphrase Goering -- is that when I hear of Schrödinger's cat, I...

Bee Hossenfelder was live-blogging from Stockholm Conference on BH info puzzle today Tuesday 25 August. Herewith: http://backreaction.blogspot.com/2015/08/hawking-proposes-new-idea-for-how.html The conference is 24-29 August. Hawking presented his idea Tuesday, based on joint work with Malcolm...

I'm very new to the understanding of Hawking Radiation. I don't know much about this theory, but I do know that Hawking radiation works on a Quantum scale. I know that with black holes this theory proposes th idea that over time black hole lose mass because of "Spontaneous appearing positive and...

According to Hawking [1] it is posited that light photons at the event horizon of a black hole must cease to move, and remain motionless for the entire lifetime of the black hole. It is also observed [http://dls.physics.ucdavis.edu/~scranton/LensedCMB/a2218.gif] (and calculated) that the path...

A book I read says that when virtual particle-antiparticle pairs are created near a black hole then sometimes one of the particle pairs will be captured by the black hole while the other one will be freed to move away as a real particle - then this causes the black hole to lose mass and thus...

Please check my logic. 1. Hawking mechanism should give birth not only to photons, but also to their heavier analogs, Z for example. 2. Contrary to photons, massive Z bosons are not gradually red shifted, low energy Z simply fall back to BH, so the "red" part of the black-body spectrum of Z is...

So I realize that I'm probably wrong about this, but it seems to me that Hawking radiation cannot be emitted only at the event horizon. If we make the (albeit almost certainly wrong) assumption that the quantity of emitted particles is directly proportional to the potential for gravitational...

Hey There, I would like to share something that crossed my mind the other day, a solution to the grandpa paradox. My solution is quite basic, The Man in the future is going to shoot himself in the past through a portal, He will not do so because if he did, he wouldn't exist in the future to...

Has the Hawking radiation ever been observed from bodies like black holes or in laboratory? From what I saw, it hasn't... 1. What are the difficulties? 2. Why are we using Hawking Radiation in some reasonings, since we haven't observed it really happening?

When the apparent horizon differs from the event horizon, as in the case of an observer falling into a black hole, does Hawking radiation take place at the former, the latter, or both?

No one seems to be bothered by this except me: Black holes have a finite lifetime measured in Schwartzchild time due to Hawking radiation. Similarly, the universe probably has a finite lifetime measured in Schwartzchild time. In that case, nothing ever falls through the event horizon of a black...

Hawking radiation talk about particles emitted from black holes. Are the particles emitted are protons and electrons? (emitted at near light speed and gradually slowdown by gravity pull of black hole as the particles move outward to fill the interstellar space of the galaxy) If yes, that means...

Hello When virtuals particles appears near a black hole , the one with a negative charge is attracted by the black hole , and as mass is proportional to energy , the black hole "evaporates" . My question is , why the particle attracted is always the one with the negative charge , is it because...

I've heard famous physicists like Stephen Hawking promote the idea that the conflict between the laws of thermodynamics and the beginning of the universe can be avoided if there is the same amount of anti-matter as there is matter, making the total energy level zero. I understand, that makes...

Here (at ~3:50) they say if the ship reaches 99% of the speed of light, a single day on the ship = year on Earth. But it looks like it's going to be one week on Earth. http://cosmology.com/images/3TimeDilationTable1.jpg Is it just a simplification of some sort in the video?

Maybe this article is more readily available than I'm aware of but thought it would be of interest to some- 'The Quantum Mechanics of Black Holes' by Stephen Hawkings http://planck.phys.uwosh.edu/rioux/thermo/pdf/Black%20Holes%20--%20Hawking.pdf

If the universe was created by the Big Bang, then how did Multiverse come into existence?