- #1
nilsgeiger
- 6
- 0
Hello.
In oral exams my professor likes to ask if Alice and Bob can communicate, if Alice ist just above the event horizon of a schwarzschild black hole and Bob ist just below.
He wants to hear:
Communication is possible, because the event horizon is observer dependent. Only an observer resting at infinity distance couldn't see something cross the event horizon.
Is this correct? I can't understand it.
Doesn't you draw diagrams like this https://faculty.etsu.edu/gardnerr/planetarium/relat/eventho2.gif exactly to see, that this is not possible?
I read about apparent horizons, but the lecture is the introduction to general relativity. We talk about an ideal schwarzschild black hole, not a perturbed black hole.
Would you please help me to understand?
In oral exams my professor likes to ask if Alice and Bob can communicate, if Alice ist just above the event horizon of a schwarzschild black hole and Bob ist just below.
He wants to hear:
Communication is possible, because the event horizon is observer dependent. Only an observer resting at infinity distance couldn't see something cross the event horizon.
Is this correct? I can't understand it.
Doesn't you draw diagrams like this https://faculty.etsu.edu/gardnerr/planetarium/relat/eventho2.gif exactly to see, that this is not possible?
I read about apparent horizons, but the lecture is the introduction to general relativity. We talk about an ideal schwarzschild black hole, not a perturbed black hole.
Would you please help me to understand?