What is Black hole evaporation: Definition and 20 Discussions

Hawking radiation is black-body radiation that is predicted to be released by black holes because of quantum effects near the black hole event horizon. It is named after the physicist Stephen Hawking, who developed a theoretical argument for its existence in 1974.The requirement that black holes lose energy into the wider universe, and therefore can "evaporate" and the radiated spectrum are both a result of analysing black hole thermal equilibrium combined with extreme redshifting effects very close to the event horizon, with some consideration of quantum entanglement effects. A pair of virtual waves/particles arises just outside the event horizon due to ordinary quantum effects. Very close to the event horizon, these always manifest as a pair of photons. It may happen that one of these photons passes beyond the event horizon, while the other escapes into the wider universe ("to infinity"). A close analysis shows that the exponential red-shifting effect of extreme gravity very close to the event horizon almost tears the escaping photon apart, and, in addition, very slightly amplifies it. The amplification gives rise to a "partner wave", which carries negative energy and passes through the event horizon, where it remains trapped, reducing the total energy of the black hole. The escaping photon adds an equal amount of positive energy to the wider universe outside the black hole. In this way, no matter or energy ever actually leaves the black hole itself. A conservation law exists for the partner wave, which in theory shows that the emissions comprise an exact black body spectrum, bearing no information about the interior conditions.Hawking radiation reduces the mass and rotational energy of black holes and is therefore also theorized to cause black hole evaporation. Because of this, black holes that do not gain mass through other means are expected to shrink and ultimately vanish. For all except the smallest black holes, this would happen extremely slowly. The radiation temperature is inversely proportional to the black hole's mass, so micro black holes are predicted to be larger emitters of radiation than larger black holes and should dissipate faster.

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  1. S

    I Supressing black hole evaporation?

    A very massive charged black hole could reach a near-extremal state in the right conditions supressing the rate of emission of Hawking radiation (https://physics.stackexchange.com/questions/490524/evaporation-of-large-charged-black-holes) Meanwhile, the radiation emitted by a black hole can be...
  2. S

    A Why do we need a quantum correction for black hole entropy?

    Hey to all,... It is now generally believed that information is preserved in black-hole evaporation. This means that the predictions of quantum mechanics are correct whereas Hawking's original argument that relied on general relativity must be corrected. However, views differ as to how...
  3. nomadreid

    I Entangled particles in black hole decay?

    First, I was not sure whether this should go into the Relativity or the Quantum Physics rubric, but since the central question is about entanglement, I opted for the Quantum. I do not have the necessary sophistication to follow string theory arguments, and even most explanations in...
  4. Kostik

    B Paradox about black hole evaporation

    Paradoxical scenario. Suppose Jack and Jill are sitting safely a kilometer above the event horizon (EH) of a large black hole. Now suppose: Jack decides to head toward the center of the black hole, traveling at an easy pace (say 10 km per hour). Jill sees Jack (with her ultrasensitive infrared...
  5. S

    B Black Hole Explosions: Hawking's 1974 Letter to Nature

    In Hawking's "Black hole explosions?" 1974 letter to Nature, he states: My question is: wouldn't it be a terrible idea to generate a black hole of any size in a particle accelerator? http://www.nature.com/nature/journal/v248/n5443/abs/248030a0.html
  6. nomadreid

    I Observing Hawking Radiation from Inside a Black Hole

    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...
  7. R

    I Hawking radiation and energy-negative energy pair production

    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...
  8. Narasoma

    Black Hole Evaporation: Confusing Red Particle & Time Dilation

    This picture confuses me. It showed here that the red particle at top right get suck into the black hole. But to a distant observer, everything near the black hole get time dilation and finally freeze at the horizon, right? So, "when" the black hole evaporates? Moreover, why the black hole likes...
  9. atyy

    Effective field theory, black hole evaporation, firewalls

    Arkani-Hamed, Dubovsky, Nicolis, Trincherini, and Villadoro argue in section 2.2 of A Measure of de Sitter Entropy and Eternal Inflation that the effective field theory description of black hole evaporation fails after a time tev, even though the curvatures are small. Almheiri, Marolf...
  10. G

    Black hole evaporation, where does it all go?

    I hear that black holes evaporate, but does it all get converted into Hawkins radiation? And what role do white holes play in evaporation?
  11. T

    Exploring Black Hole Evaporation: Mass and Entropy in Thermal Radiation

    During black hole thermal radiation can mass be radiated while entropy stays? Is it possible that entropy stays in the singularity?
  12. A

    Question about proton decay and black hole evaporation

    Just to start, let me reassure you that I am not an LHC alarmist. I understand and agree with the cosmic ray explanation, i.e. earth, the sun, jupiter, and everything else would be a BH if they didn't evaporate. Anyway, I was reading around a little on wikipedia and came to this page...
  13. C

    Understanding Black Hole Evaporation with Hawking Radiation

    With the theory of Hawking Radiation, people generally say to imagine that the black hole has a temperature, so it must radiate heat. But, this really is not how it is said to work. The means by which the black hole evaporates is not that particles are actually coming out of it, or that it is...
  14. R

    Black Hole Evaporation: Exploring Mass Loss

    black holes evaporate, i know that it sounds like it defies all rational elucidation but i think that black holes evaporate. see black holes emmit black body radiation they also emmit hawking radiation and hawking radiation as far as I am informed shrinks black holes it causes them to lose mass...
  15. Z

    Black Hole Evaporation: Charged Particle Energy Effects

    in classical electromagnetic a charge can make energy. Now consider Howking radiation effect: if an anti-particle fall into the BH the volume of BH will reduce. But if that particle be a charged particle, this charge can make positive energy and increase the volume. Is that right?
  16. D

    Exploring Black Hole Evaporation and Its Explosive Effects

    If it is indeed true that black holes (eventually) evaporate, then once they lose enough mass do they then return to become a normal body of matter? I would assume that once this happens there would be an enormous explosion due to constraints of relativity disappearing.
  17. belliott4488

    How does black hole evaporation end?

    Someone asked me what happens when micro-black holes evaporate, and I have no idea, not really knowing anything about the theory of black holes, other than what you learn in a first course in GR. What he was asking was whether the black hole just keeps emitting energy (in the form of Hawking...
  18. A

    Hawking Radiation and Black Hole Evaporation

    I've been trying to discover a qualitative description of Hawking Radiation and Black Hole evaporation and haven't been able to find one yet. I figured this board might offer some insight. Can someone explain to me how a 'virtual' pair differs from a 'real' pair? It seems to me that no...
  19. A

    Does Black Hole Evaporation Result in Visible Emission and Directional Output?

    According to the Black Hole evaporation theory, Hawking Radiation is emitted from the black hole. My first question is: Does it emit in one single direction or at polar opposites, and my second is: What happens when enough matter is emmited, does the black hole suddenly become visible again...
  20. marcus

    Bojowald and Ashtekar: Black hole evaporation paradigm

    http://arxiv.org/abs/gr-qc/0504029 Black hole evaporation: A paradigm Abhay Ashtekar, Martin Bojowald 18 pages, 4 figures IGPG04/8-4, AEI-2004-072 "A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results...