Radiation that comes from pair production quantum effects in close vicinity to an event horizon, leading to the potential for eventual evaporation of black holes. Two mirror particles are created with one falling behind the horizon, becoming casually lost to the rest of the universe, including its ...

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How would one attach black hole to starship in the Black hole Starship model? [on hold]

A black hole starship is a theoretical idea for enabling interstellar travel by propelling a starship by creating an artificial black hole and using a parabolic reflector to reflect its Hawking ...
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1answer
42 views

Why does imaginary periodic time of the Rindler space of black hole give Hawking temperature?

The metric of a Schwarzschild black hole in Rindler coordinates is $$ds^2= -\frac{\rho^2}{(4MG)^2} dt^2 +d\rho^2 + d\mathbf x_\perp$$ where $\rho$ gives us the distance to the horizon. If we switch ...
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40 views

Could dark energy and Hawking radiation be the same thing? [on hold]

Specifically, could black holes effectively emit some kind of negative mass or other form of dark energy, so that the mass of the black hole itself would actually increase rather than decrease ...
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2answers
93 views

A doubt regarding Black Hole Complementarity

A friend was explaining Black Hole Complementarity to me, and at one point he said that to get a (horrendously) mixed quantum state, i.e. a thermal density matrix without a heat bath, one takes a ...
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0answers
54 views

Why would a black hole evaporate? [duplicate]

Hawking radiation doesn't make sense to me, with respect to black holes getting smaller. It would seem that any particle (or anti-particle) leaving the Schwartzchild radius would have a similar ...
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+200

An explanation of Hawking Radiation

Could someone please provide an explanation for the origin of Hawking Radiation? (Ideally someone who I have been speaking with on the h-bar) Any advanced maths beyond basic calculus will most ...
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2answers
123 views

Is this analogy of Hawking Radiation correct?

Through reading of textbooks and other research papers, I have settled on the analogy of hawking radiation below (Written completely by myself) Within the ergosphere of the black hole, virtual ...
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1answer
76 views

If an object has a temperature, does it have to radiate?

I'm reading through a powerpoint presentation about Hawking Radiation (HR). They are explaining all of the reasons that built up to the postulate of HR, and one of the reasons is that if there is a ...
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18 views

Hawking radiation and energy-negative energy pair production [duplicate]

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 ...
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Existence of anything below event horizon of a black hole

I have recently listened to L. Susskind's lecture on youtube and could not quite get some it's points. As far as I understand the argument is as follows. Suppose we have region A inside event horizon ...
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55 views

Information from inside a black hole

Now I'm hardly a physicist, but I am pretty interested in it. I was thinking about black holes and the movie Interstellar, and if you've seen it, then one of the central points about it is that they ...
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2answers
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Why does an evaporating black hole always stay a black hole?

Stars can only collaps and form black holes if their masses are above the Chandrasekhar limit, $M>M_{\rm Pl}^3/M_{\rm hydrogen}^2$. When the universe eventually cools down enough, the black holes ...
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49 views

Spaghettification on an atomic scale?

Spaghettification occurs when an object approaches a singularity. As one comes close enough to the singularity, the gravity at the feet (if this is a human) is greater than that at the head, ...
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1answer
57 views

How much energy is released by an evaporating black hole in the last second of its life?

From what I understand, due to Hawking radiation, black holes lose mass in the form of energy (electromagnetic radiation), with these characteristics: The larger the black hole, the less energy it ...
1
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1answer
48 views

Event horizon, and Hawking radiation [duplicate]

When the escape velocity from EH is c, then how can Hawking radiation escapes it? Does it travel faster than c? Or, it escape from outside the EH? If so, how a BH can evaporate beyond EH?
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28 views

Does inflation violate the second law of thermodynamics?

Does inflation violate the second law of thermodynamics? It seems like it would, since quantum fluctuations were scaled up and created the varying density field that lead to Galaxy formation. ...
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32 views

Can a micro black hole hover above a regular black hole?

So let's say you have a black hole $A$, that is small enough for its gravity to be very small, but has strong hawking radiation, and larger black hole, $B$, with very small hawking radiation, but ...
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2answers
74 views

Derivation for the temperature of Reissner-Nordström (charged) black hole

A lot of the text for this is from "How does one correctly interpret the behavior of the heat capacity of a charged black hole?" but this concerns a different question. The Reissner-Nordström black ...
3
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3answers
93 views

Can light escape a black hole? [duplicate]

I heard that a black hole is not black because it's escape velocity is greater than or equals to the speed of light. But instead it is black because the light that gets emitted from a black hole gets ...
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1answer
39 views

Black hole expiration dates [closed]

According to this answer: http://physics.stackexchange.com/a/150020/36709 Very "light" black holes have a life expectancy in the range of $10^{18}$ years while very "heavy" black holes have a life ...
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0answers
101 views

Can black holes with the same mass evaporate with different speeds?

I am curious about the following observations: (1) For a normal Schwarzschild black hole, it evaporates according to $dm/dt=-1/m^2$; (2) We have eternal black holes which do not evaporate (though ...
3
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64 views

Merger of old black holes

On the eve of a possible announcement on the production of gravitational waves via a black hole merger, I think this question is quite aptly timed. I have a few questions regarding the evolution of ...
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Black hole starship: Would micro black-hole Hawking radiation emit anti-matter?

My understanding of Hawking radiation is that virtual particle pairs of matter and anti-matter are created from vacuum energy and one of those virtual particles may escape while the other enters the ...
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54 views

In kerr's black hole solution can the Bekenstein-Hawking entropy be descrete?

In kerr's solution we have: $S_{BH}=\frac{k_{\beta}c^{3}A}{4G\hbar}$ where A is the area of the horizon and equal to $A=8\pi G^2 m(m+\sqrt{m^2 - a^2})$ where $a=\frac{J}{mc}$ and J is the angular ...
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50 views

Hawking radiation for an observer at infinity

As an external observer at infinity, I observe a star collapsing. But because the surface of the star will be infinitely redshifted, I will never see the formation of the black hole. For me, there ...
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Hawking radiation: why do only negative mass particles fall into black holes? [closed]

So I have read other questions asked about this topic, but they focus more on positive or negative energies of the virtual particles, and I want to ask specifically about the negative mass issue. ...
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26 views

Considering Hawking radiation, can an object ever actually cross event horizon of a black hole? [duplicate]

The Schwarzschild solution of Einstein's field equations clearly shows that a far away observer sees time slow down for an in-falling object. Relative to him, it takes an infinite amount of time for ...
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1answer
74 views

Hawking radiation and black hole evaporation [duplicate]

As I understand it, Hawking radiation predicts black hole evaporation because of quantum effects. After the creation of a particle/anti-particle near the horizon of the black hole, if the one gets ...
0
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0answers
48 views

Hawking paradox [duplicate]

Over the centuries, physicists "gave up" on conservation of elements, conservation of mass and then conservation of energy, which now we know to be related to symmetries. How can we be sure that ...
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1answer
131 views

Black Hole Matter to Subatomic Exchange

When matter enters a black hole with a singularity the particles smaller than photons released come from within the black hole or do subatomic particles shed from matter just before matter passes the ...
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0answers
25 views

Clarification on hawking radiation [duplicate]

I read that a pair of entangled quantum particles can spontaneously pop into existence for a brief moment and especially near to the event horizon whereby one of the entangled quantum particle passes ...
2
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1answer
53 views

Does the universe emit Hawking radiation?

Would there be any experimental validation from cosmological observation?
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Does any ordinary object emit radiation due to Unruh effect and equivalence principle? [duplicate]

I am just wondering is there Hawking radiation for any object (that has mass) due to its gravity. Base on the Unruh effect and equivalence principle, any object should emit Black-body radiation or ...
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Event horizon temperature

If the acceleration of a particle at the event horizon is "infinite", then its Unruh radiation must be infinite. Yet the Hawking radiation of a black hole is finite.. how comes the difference?
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Can virtual particles be 'boosted' into becoming real particles by fields other than gravity?

On the wikipedia page for Hawking Radiation it states: Physical insight into the process may be gained by imagining that particle-antiparticle radiation is emitted from just beyond the event ...
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3answers
331 views

Why is it that black holes emit Hawking radiation? [duplicate]

Black holes are basically neutron stars with such a gravitational force that even light cannot escape from it. But what causes it to emit Hawking radiation?
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1answer
419 views

If Hawking radiation is proved to be true won't black holes lose entropy which is against laws of thermodynamics?

Hawking radiation states that black holes continuously emit radiation. But if its the case won't entropy of black holes decrease which violates the laws of heat, entropy and thermodynamics?
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If nothing can escape a black hole, where does Hawking radiation come from? [duplicate]

Hawking radiation is a form of electromagnetic wave travelling at the speed of light. Hawking radiation is radiated from a black hole. If nothing can escape the gravitational pull of a black hole, how ...
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2answers
153 views

Why can black hole evaporate if objects need infinity time to reach event horizon (as seen by a distant observer)?

I am new to black hole, but have a question about it: Object needs infinity time to reach event horizons (as seen by a distant observer). Particle-antiparticles separates, one of them drops into ...
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0answers
60 views

The integrals in the paper (Hawking radiation as tunneling)

In the paper PRL 85(2000), 5042, "Hawking radiation as tunneling", by Parikh and Wilczek, there are some integrals, such as Eqs.(6) and (8). They are like this: $$I=-Im ...
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Is Hawking radiation valid for a microscopic black hole?

A black hole evaporates by Hawking radiation. The computation of the evaporation time uses some approximations. Question: Is the evaporation time valid for a microscopic black hole? In particular, ...
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49 views

Assumptions needed to derive Hawking radiation

To derive many singularity theorems in GR you need only assume that GR is correct and the weak energy condition or something similar. My question is what are the assumptions needed to derive Hawking ...
3
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0answers
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If it takes infinitely long for someone to fall in a black hole, wouldn't it evaporate first? [duplicate]

Let's say I decide to jump into a large black hole. A distant observer never sees me enter the black hole, but he does see the black hole evaporate. According to this reasoning, I would then keep ...
2
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3answers
122 views

What is the binding energy of a black hole?

As the particles which constitute a black hole collapse they become tightly bound. I assume this means a lot of energy would be required to liberate a particle from that bound state. Is it a finite ...
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4answers
3k views

Why do physicists trust black hole physics?

Based on popular accounts of modern physics and black holes (articles, video lectures), I have come to understand the following: Black holes are predicted by General Relativity, a classical theory ...
6
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2answers
238 views

Are black holes eternal?

The question might sound very easy - Hawking radiation, however I was pondering that as you get closer and closer to a black hole, time dilates exponentially where the surface of the black hole is ...
2
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2answers
143 views

Possible paradox with black holes and time dilation [duplicate]

I am by no means an expert in the realm of physics. I do from time to time, try to understand the concepts of modern physics and their applications. I came across this video that I am currently ...
23
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1answer
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How does one correctly interpret the behavior of the heat capacity of a charged black hole?

Note: Although I have a provided an "answer" to the question, I did not resolve all the questions in this post satisfactorily. I invite anyone willing and able to provide a better answer, which I ...
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Connection between Black Hole Firewalls and Hawking Radiation

In a previous post, I asked what constitutes a black hole firewall--namely, what is a possible mathematical description of the firewall. Now I have a new question, which is based around this guest ...
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What constitutes a blackhole firewall?

I understand that, to break the entanglement of two particles of Hawking radiation and therefore preserve monogamy of entanglement, there should be a firewall around the event horizon. This firewall ...