Is crossing a black hole's event horizon possible?

In summary, crossing a black hole's event horizon is theoretically possible according to general relativity, but it leads to a point of no return. Once crossed, nothing, including light, can escape due to the extreme gravitational pull. While the physics suggests it can happen, any matter or information that crosses the event horizon becomes irretrievable, making it unlikely for anyone to survive or observe the experience.
  • #36
Tomas Vencl said:
If I were to observe any effect of crossing the horizon on Earth, I would retrocausally gain information about the future behavior of the shell
The word "retrocausal" might be confusing some people. A better way to put this would be that the fact that you can't know in advance the entire future behavior of the shell (and the spacetime in general) is why you can't observe any local effect when you cross the event horizon. Or, to put it another way, the event horizon is not locally defined, it's globally defined; to know where it is, you have to know the entire spacetime, including the entire future.
 
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  • #37
The velocity time-dilation curve as v approaching C resembles the gravitational time dilation curve for r approaching Rsch. If SR predicts time reversal for V>C ("FTL"), does GR predict anything similar for inside the EH (r < Rsch)?
 
  • #38
Eclipse Chaser said:
If SR predicts time reversal for V>C
It doesn’t.
 
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  • #39
Eclipse Chaser said:
If SR predicts time reversal for V>C
It doesn't.
 
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  • #40
Beat me by a nose!
 
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  • #41
Vanadium 50 said:
Beat me by a nose!
Those posts may have had spacelike separation! 😂
 
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  • #42
srb7677 said:
in a process picturesquely dubbed "spaghettification".
@srb7677 just as a minor aside in this thread, that statement is not generally true. It IS true for small and modest sized black holes but it is definitely not true for massive and supermassive black holes, so you need to be more specific, rather than making a general categorical statement.
 
  • #43
phinds said:
@srb7677 just as a minor aside
He has been gone for months. The thread got restarted when someone else had a different misconception.
 
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  • #44
Vanadium 50 said:
He has been gone for months. The thread got restarted when someone else had a different misconception.
What fun, eh?
 
  • #45
RE: Inside the EH: Well that was convincingly quick! Returning to SR, if the velocity time dilation equation T = T0 x Sqrt ( 1 – V2 / C2), goes imaginary, (but not necessarily negative), can you direct me to the mathematical or other reasoning that predicts time reversal for V>C (FTL)?
 
  • #46
Eclipse Chaser said:
can you direct me to the mathematical or other reasoning that predicts time reversal for V>C (FTL)?
No, because it is your claim, and it is wrong.
 
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  • #47
This thread is closed.
 

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