Is crossing a black hole's event horizon possible?

[PeterDonis]

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.

 

[Eclipse Chaser]

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)?

 

[Orodruin]

If SR predicts time reversal for V>C

It doesn’t.

 

[Vanadium 50]

If SR predicts time reversal for V>C

It doesn't.

 

[Vanadium 50]

Beat me by a nose!

 

[Orodruin]

Beat me by a nose!

Those posts may have had spacelike separation!

 

[phinds]

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.

 

[Vanadium 50]

@srb7677 just as a minor aside

He has been gone for months. The thread got restarted when someone else had a different misconception.

 

[phinds]

He has been gone for months. The thread got restarted when someone else had a different misconception.

What fun, eh?

 

[Eclipse Chaser]

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)?

 

[Vanadium 50]

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.

 

[PeterDonis]

This thread is closed.