Hawking Definition and 329 Threads

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...

Seeing as it was so integral to the standard model and since the SM is so remarkably successful, aside from its inability to predict the correct amount of vacuum energy, and seeing as no experiment has proved it wrong, why did Hawking bet against it? It was only a 100 dollars so maybe he was...

The term "negative energy" is used (a) for the energy below the vacuum energy between the two plates in the Casimir effect, (b) the energy carried by the sister particle to the radiated particle in Hawking radiation, that is, the particle from the matter-antimatter pair which goes into the...

Hi all, I was studying Stephen Hawking's new book (very good, by the way). He was explainning Feymann's theory, that says a particle travels by all the ways possible to reach a given point. So single particles CAN have interference by themselves. Then he explain why, in the double slit...

I know their is a theoretical answere to this or else the theory would have no traction... If a black hole emits a particle at a high speed, wouldn't logic say that the black holes immense gravity simply pull it back in? Also, what kind/size particle is theorized to eject?

What's the "color" of Hawking radiation? If I understand correctly, the Hawking radiation hypothesis predicts that if a pair of virtual particles appears very close to the event horizon of a black hole, it may happen that one of them falls into the black hole and the other escapes, becoming a...

on pg 324 of Schutz's "A First Course in General Relativity", i am having a little trouble with the integral (11.100). the book says that to first order in \epsilon , the answer should be 2\sqrt{2M\epsilon} but i keep getting \sqrt{2M\epsilon} . i am missing that factor of 2 somehow. the...

In order for the black hole to evaporate it must have a temperature greater than that of the present-day black-body radiation of the Universe. Cosmic microwave background radiation temperature: T_u = 2.725 \; \text{K} Hawking radiation temperature: T_H = \frac{\hbar c^3}{8 \pi G M k_B}...

I came across this statement from James Hartle on Stephen Hawking's website, http://www.hawking.org.uk/ and wondered where you see this proposal currrently [Hartle sure seems to think it explains an awful lot] : James Hartle: Wikipedia has a brief discussion here...

The Hawking-Unruh temperature is given by the expression: \large T = \frac{\hbar g}{2 \pi c k} where g is the gravitational acceleration at the surface of a black hole. Does this expression imply that any gravitating body will emit Hawking radiation? For example if we take the...

((Wasnt sure where to post this one, but i felt this spot was good)) Okay Dr. Stephen Hawking conducted a time travel experiment in an attempt to prove that time travel will be invented one day. The basic idea was to throw a party for time travellers and announce the time and location of the...

I can't wait for this. I suspect it to be only a short appearance, you know how it is. I wonder if he argues with Sheldon http://www.bbc.co.uk/news/entertainment-arts-17337778 I know some of you may hate TBBT as it stereotypes, I guess. But take it as it is.

Hello everybody, I am currently studying QFT on curved spacetime and I got puzzled about the question: Are Unruh and Hawking effect just the same by invoking the equivalence principle? I found ambiguous statements and this paper contributed to it. http://arxiv.org/pdf/1102.5564v2.pdf...

Hi all, :smile: Stephen Hawking extended the Godel's Theorem to physics and hence expressed that single TOE does not exist. So, :shy: does that mean that single GUT cannot exist as well? I guess not, in a sense that GUT might not necessarily mean TOE. I just want opinions. Sincerely DPA

According to Hawking Radiation, a black hole if left alone will eventually evaporate. As the black hole loses mass the area of the event horizon shrinks until both are gone. The Hologram Theory says that as matter falls past the event horizon all the information pertaining to that matter is...

Do you agree with Stephen Hawking when say "Philosophy is dead" ? *I would have posted it in the philosophy sub-forum , but I thought the material might not meet the guidelines . The content of this thread would fit a general and informal discussion more , I thought. Please move it to any...

After watching Discovery's documentary "Curiosity: Did God Create the Universe?", I can't stop but wondering,... Dr. Hawking claims that there is no time in a black hole. Time stops due to the Gravitational time dilation. The very beginning of the universe is also a black hole. There is no time...

Micro black holes should in principle be observable by emitting Hawking radiation. However, as this takes place extremely close to the event horizon, shouldn't one expect then extreme redshifting (z = 1/(1-Rs/R)^-1/2 -1, Rs = Schwarzschildradius, R = Radius of Emission) and time dilatation? In...

I understand that to obey conservation that the black hole must lose energy and mass and the surrounding space must gain an equal amount of energy and mass. Then why can the antiparticle not be emitted from the black hole, adding negative energy and mass to the surrounding space, and the...

I know that Hawking Radiation is caused by the separation of virtual particles on the event horizon of a black hole, but I do not understand why the antiparticle is always the particle from the pair that falls into the black hole. It seems to me that the gravitational effects of the black hole...

I was wondering if virtual anti particles had a postulated anti gravitational charge if that would be inconsistent with Hawking radiation as virtual anti particles would always be ejected from the vicinity of the Schwarzschild radius whereas virtual particles may or may not be ejected depending...

Not sure if this is the right forum but hey ho.. I have been reading about Hawking radiation in Black Holes, whereby virtual particles are created at the event horizon and of the particle and anti particle pair 1 can escape before it is annihilated. Why are the particles which make up the...

So from what I understand when the particle anti-particle pairs that are constantly being created and annihilated come into existence near a black hole's horizon, the nearer one can get sucked in while the further one can radiate off as though it were heat. And this radiation of energy decreases...

i have read about Hawking's theory of BH radiation based on the idea of spontaneous particle pair creation at the EH wherein, on occasion, one of the particles is absorbed by the BH while the other escapes to become real. since the one which is absorbed is always of negative energy (whatever...

I've been reading about it various places online, but I can't seem to find a straight answer. Is information lost when black holes disappear, or not? Thanks!

My (very basic) understanding of at least some form of Hawking Radiation is that, upon the formation of a particle/anti-particle pair near the event horizon, the black hole sucks in an anti-particle leaving the non-paired particle to go off into the universe as "radiation." But what about the...

Stephen Hawking on Discovery's "curiosity" I recently watched Stephen Hawking on Discovery's "Curiosity" and found his assertion that a grand designer could not exist based on the logic that there was no time before the big bang troubling.(Due to the fact that the universe before the big bang...

Hi PF I was wondering, if Hawking radiation could have a different source than black-body radiation. I was wondering, if quantum tunneling could be a possible way, for energy to slip out of the grasp of the black holes gravitational attraction and slip through the event horizon. Would this be...

As far as I know, the classic paper applying the Hawking singularity theorem to our universe is this one: Hawking and Ellis, "The Cosmic Black-Body Radiation and the Existence of Singularities in Our Universe," Astrophysical Journal, vol. 152, p. 25, 1968...

Can anybody help me with the original calculations of hawking radiation. I am working out the details of Hawking's original paper on black hole radiation. I am getting stuck at many places. Does anyone know about some place where the detailed calculations can be found.

Has hawking radiation ever been observed?

According to Blackhole thermodynamics a black hole has an entropy that is proportional to its surface area and a temperature called the Hawking temperature. If one multiplies the Hawking temperature by the entropy one gets a thermal energy. Would this energy be equal to the mass/energy of...

What is the equation for the energy/frequency of Hawking radiation emitted from a black hole? Thank you in advance! EDIT: I found this http://library.thinkquest.org/C007571/english/advance/core5.htm but the website doesn't seem to be a legitimate source and it doesn't give the derivation of the...

I was watching Stephen Hawking Into the universe and he was talking about time travel. So I got to thinking if time travel into the future is possible then that would mean time isn't a paradox mankind made up and it is physical. Not sure if the formula is even any where right but this is what...

Novice question. Reading more of today's http://au.news.yahoo.com/world/a/-/world/9454304/heaven-is-a-fairy-tale-says-physicist-hawking/" , an article on Hawking has this line: Addressing the question "Why are we here?" he will argue tiny quantum fluctuations in the very early universe...

Stephen Hawking gives his take on the "afterlife" Stephen Hawking recently gave his view on death and apparently people are shocked by the answer. http://news.yahoo.com/s/yblog_thelookout/20110516/us_yblog_thelookout/stephen-hawking-says-afterlife-is-a-fairy-story Since so many people...

I stumbled upon an article while doing some research that had a statement saying that Hawking radiation can be found in places beyond black hole horizons. This lead me to this paper (which I'm not actually interested in beyond it's reference to the existence of hawking radiation outside of...

Awesome! http://www.youtube.com/watch?v=zn7-fVtT16k&feature=channel_video_title See the rest of the series for more awesome!

how can hawking radiation escape from a black hole? thanks

In his theory, Stephen Hawking suggests that a black hole will give off thermal radiation. Radiation is light, so how can light escape the gravity of a black hole, especially originating from one? The only way I could see this was that if radiation were traveling beyond the speed of light, but...

Is it true to say that Hawking radiation isn't actually the temperature of the black hole but rather, the temperature of the thermal radiation it emits due to quantum effects? Thanks.

i have posted a few questions regarding Hawking radiation in the past, regarding the assumption of "negative energy" of the particle which falls into the BH. i have tried to do as much reading as i can on the topic, since i have had a very hard time absorbing the concept of negative energy...

I have heard a lot of mixed opinions regarding Stephen Hawking and some of his publications. He is widely considered to be a genius and one of the greatest scientists of modern times but most of these opinions come from outside the scientific community. I have also heard that he is rather up...

Article : Hawking contra Philosophy Do you think Stephen Hawking's comments on philosophy ought to be embarrassing to the great physicist?

I was having a conversation with a physicist on Facebook (author of a book I rather enjoyed - "Users guide to the universe"), and he let the conversation end without my question ever being fully answered. Perhaps someone here can help explain this to me. I'll paste the entire conversation...

My understanding of Hawking Radiation is that a particle and anti-particle form at the event horizon, the particle escapes, the anti-particle goes into the black hole, annihilates a particle at the core of the black hole, and energy is released, leading to an evaporating black hole. But how do...

This question came to me during my reading of "A Brief History of Time" and learning of Mr. Hawking's statement of the universe arising spontaneously from chaos as a result of the law of gravity, which would preclude a God's role in creation. ABHT states that "one could still imagine that God...

I read about Hawking Radiation a while ago (Scientific American?), and just thought of something that seems to not agree with it: Unless my memory is wrong, then at the event horizon the virtual particle pairs of the "vacuum" are split, and the anti-particle falls into the black hole, and the...

On "when does Hawking radiation begin?" I have wondered about when, during collapse, Hawing radiation starts (given that an outside observer never sees the horizon reached, classically at least), and asked this here without getting answers (presumably, because there is no well founded answer)...

Hi ! I'm trying to understand the Dark matter problem, because it scares me if clever people tell me they don't know out of what 23% of the universum is consisting. But let's start with a simple question on GR: GR is stating that a body moving at a speed close to c holds an almost...