At 10:23 PM 12/26/2012, David Roberson wrote:
We both agree that nothing will happen to the ship itself unless tidal forces tear it apart. That has not been an issue and I am not sure of why you start with the assumption that I think it will. You must have misunderstood my statement. I suppose I could have made it in a clearer manner.
I never objected to the thought experiment, nor thought that this would be an issue. We can imagine a teeny-tiny spaceship that is super strong. and we can imagine a really big black hole, so that the curvature doesn't bite us.
The ship itself will never think it reaches the ultimate boundary but we will see radiation emitted by it become red shifted until no more detectable energy comes our way from it.
I'm no longer confident of any of the explanations. The holonauts never see the singularity, but if they are travelling toward it, in their own time, they see an event horizon ahead of them, becoming smaller more and more intense, I'd think. However, lots of sources say that events beyond the event horizon are meaningless.
Part of what is frying my brain here is the gravitational field at the event horizon. The event horizon is defined as the boundary where gravity is so intense that light cannot take a path that increases its distance from the center of gravity. That's geometrical. If the holonauts pass the originally observed event horizon, and see a receded event horizon in front of them, how would the light paths have shifted? It doesn't seem that time dilation would do this.
The sense I keep coming up with is that the event horizon is the place beyond which light cannot escape to the *external universe*, which means infinite distance, I found one article that refers to this. Not that it cannot escape to some greater distance.
But that contradicts the "gravity so intense" statements, and the light path statements.
I need to examine doppler shift from gravity more closely. I clearly don't understand the extreme case, where light not only can't escape to infinity (equivalent to escape velocity), but it can't go up *at all*. That means that the shift takes place immediately on emission, not upon rise through a gravitational field.
That is what I refer to as blink out of existence, not actually be destroyed. This process with take an infinite amount of time to complete so I guess theoretically it is always detectable until the noise hides what is left of the low frequency energy.
Where do you get the "infinite amount of time" from? It seems you are claiming that *our time* slows down.
The mass of the ship will appear to become infinite to us as it fades into the noise and the spaceman will appear to freeze in place due to time dilation. From our perspective, the ship becomes frozen at what we believe is the event horizon, although the other closer observers will not agree with our location determination.
I don't think so. The mass of the ship is incorporated into the mass of the black hole, and that's not infinite. The information coming to us from the ship, as I mention, would be doppler-shifted, but the velocity of the ship would be increasing, acceleration due to gravity. How would we know where the ship is? I mentioned how: I assume we know the gravitational field, and the ship is sending us photons. If they are gammas, they'll last longer! From the doppler shift in them we will know where they are in the field. (They will not be travelling at relativistic velocities.) As they approach the event horizon, the signal will be increasingly red-shifted, and it will end when they cross the event horizon. The photons still travel at the speed of light. They are not slowed, they are doppler-shifted.
Once before a long time ago you strongly disagreed with the idea of time dilation for a traveler as he enters a black hole. I suspect that you now realize that this must occur.
Sure. I don't recall disagreeing with it, however. Just to be sure we are on the same page, the traveller does not experience time dilation. We observe it when we observe a traveller clock. Time dilation does *not* mean that the traveller appears to slow down.
Yes, I see that now you understand that the spaceman nearing what we considered the event horizon sees to the other side.
I understand what you *mean* but I'm not relating this to the traveller nearing the event horizon. They don't see beyond *their* event horizon, that's clear. The question I'm getting is how the event horizon is located. Does the curvature of space depend on where we are?
There is something we are not considering here.
He can continue to communicate with the first guy that started ahead of him on the journey and report back to us. That is what I have been trying to prove all along.
This involves a paradox. There is contradictory information out there, as far as I can tell, or we are interpreting it in a way that leads to contradictions.
Who said off topic discussions are not interesting and educational?
Not I!
Dave -----Original Message----- From: Abd ul-Rahman Lomax <[email protected]> To: vortex-l <[email protected]>; vortex-l <[email protected]> Sent: Wed, Dec 26, 2012 9:53 pm Subject: Re: [Vo]:[OT]:Question About Event Horizon At 05:55 PM 12/26/2012, David Roberson wrote: >That makes it a bit more complicated. I was referring to the exact >radius at which light can not escape from a non spinning black hole >as observed from far away. If a space ship reaches that radius from >our perspective, it would totally blink out of existence. No. Actually, nothing happens to the spaceship. Neglecting tidal forces or other effects from the environment near a black hole, it doesn't even experience the event horizon as anything special. Ummm.... it might start to see things that can't be seen from outside. Like what is in the hole and what is on the other side. What happens is that the space ship becomes unobservable to us, except the mass is still there. The mass of the black hole increases by it. If I'm correct, gravity is the only observable that remains.
