All Questions
14
questions
-1
votes
1
answer
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Black Body Radiation similarity to Hawking Radiation
Do black body radiation of a 40-Earth mass osmium planet with radius of Earth which was just formed and has a temperature of 10000 degrees Celcius emit photons not just near it but even at infinity ...
- 1,534
1
vote
0
answers
25
views
Do all small-large AdS black hole phase transitions have swallow tail like behaviour for the Free Energy v/s Temperature plot?
In the literature the swallow tail like behaviour is prominently seen for small-large AdS black hole phase transition for the Free Energy vs Temperature Plot. Recently I was trying to reproduce the ...
- 193
0
votes
0
answers
62
views
Are black holes black body? [duplicate]
I've read online that black holes are almost ideal black bodies. But for a body to be called an ideal black body it should emit all the rays of all the wavelengths but black holes don't, so how can we ...
- 21
3
votes
1
answer
128
views
Can an evaporating black hole emit protons with an energy beyond the GZK limit?
There are protons reaching the earth with energies that exceed what their interaction with the cosmic microwave background should allow, the so-called GZK limit.
Could an evaporating black hole emit ...
user353451
2
votes
2
answers
101
views
Will a black hole disappear?
Reading The brief history of time by Stephen Hawking and the chapter 7 BLACK HOLES AIN’T SO BLACK has below.
Does it mean if his theory is correct, a black hall can disappear on its own?
Because ...
- 169
2
votes
1
answer
346
views
Black body (Black hole) radiation
I have a question regarding Black body (black hole) radiation.
Is it correct to say that the black hole radiation is the hawking radiation? How is the formula for the wavelength of hawking radiation ...
- 1,398
9
votes
2
answers
693
views
How does Hawking radiation emerge from the shadows?
Imagine you have a large black hole, onto which you drop a small object. This object could have any shape you like, but later on it will look like a thin sheet, so we could imagine it starts that way, ...
rob♦
- 91.5k
0
votes
1
answer
38
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Charged Black Hole: Self-Discharge
Palti writes in his introduction to the swampland (page 39) that a charged black hole (BH) could discharge itself, when the Hawking temperature
$$
T_H=\frac{R_+-R_-}{4\pi R_+^2}
$$
($R_+$ and $R_-$ ...
- 938
11
votes
2
answers
836
views
Thermal radiation contains no information?
I have often read that
thermal radiation contains no information.
Could someone elucidate this claim?
The statement looks puzzling to me because in apparent contradiction with the two following ...
- 5,220
-1
votes
1
answer
568
views
Why we expect a black hole to have an emissivity of 1? [duplicate]
Just wondering: why we expect a black hole to have an emissivity of 1?
Can anyone give some ideas?
- 1
0
votes
0
answers
51
views
Black hole absorbing photons?
If a black hole has a radius that is not that much smaller than the wavelength of light emitted by the sun, and is at the same temperature, shouldn't it be able to absorb photons as well as emit them? ...
- 36
1
vote
2
answers
541
views
Does the Earth emit heat?
I'm reading my first book on physics "Seven brief lessons on physics" by Carlo Rovelli, and in his chapter on "Probability, time and heat of black holes", he mentions that Stephen Hawking showed that ...
- 123
2
votes
2
answers
241
views
How much work can we extract from a black hole?
Recently, I've read an article on scientific regarding the possibility of a stairwell into a blackhole (unsurprisingly, it isn't possible).
I've found the following question more interesting:
...
- 459
56
votes
2
answers
3k
views
Is the Hawking radiation of a charged black hole thermal?
Suppose you have a Schwarzschild black hole of mass $M$ and angular parameter $a = 0$ (no rotation).
Question: is it possible to throw a charge $Q$ at a faster rate than it will be re-radiated? Will ...
- 14.5k