Tagged Questions
3
votes
3answers
252 views
Vacuum energy and perpetual motion
The part of the Einstein equations of general relativity referred to vacuum energy, introduce a repulsive term in gravity. This means that as the space become bigger and bigger, vacuum part become ...
3
votes
2answers
225 views
Hawking radiation and black hole entropy
Is black hole entropy, computed by means of quantum field theory on curved spacetime, the entropy of matter degrees of freedom i.e. non-gravitational dofs? What is one actually counting?
-1
votes
1answer
154 views
What if microstates increase proportional to universe volume?
I am probably a delusional crank with a lot of crazy, overly speculative conjectures. If I am not delusional, than at the very least I've been ahead of the curve, the last 40 or so years. I was a ...
6
votes
1answer
376 views
Wick rotation and the arrow of time
It is well known that we can switch from a statistical system to a quantum mechanical system by a Wick rotation. Has this rotation some implication on the way the time flow? namely, this is an ...
5
votes
1answer
174 views
Is a black hole's surface area invariant for distant intertial observers?
Let's imagine I'm very far from any massive objects, so my local space-time is Minkowskian. Off in the distance is a black hole, far enough away that it doesn't noticeably curve space-time near me, ...
9
votes
3answers
480 views
Why does large curvature of spacetime imply high temperature?
I`ve just stumbled about a sentence which says that high curvature of spacetime implies that any matter present is at high temperature.
This somehow confuses me, so my probably dumb question(s) are:
...
9
votes
1answer
399 views
Second Law of Black Hole Thermodynamics
I've been looking for a satisfying proof of this, and can't quite find it. I read the brief proof of the black hole area theorem in Wald, which is similar, but doesn't quite come down to the actual ...
5
votes
1answer
204 views
Why can't Schwarzschild wormholes exist?
So, I've recently been reading up on Schwarzschild wormholes and I've learned that they cannot exist becuase they violate the 2nd Law of Thermodynamics.
What I'm asking is: Why do they violate the ...
2
votes
2answers
68 views
In a gas of particles, how is the displacement vector related to the number density?
Suppose I have a gas of particles that is initially uniformly distributed so that the number density is $n_0$ (number of particles per unit volume), and then I displace the particles by the vector ...
4
votes
1answer
191 views
What kind of systems of black holes satisfy the laws of black hole thermodynamics?
I've come across black holes thermodynamics multiple times recently (both at this site and elsewhere) and some things started bugging me.
For one thing, first law bothers me a little. It is a ...
