I think that might be the way it could be calculated. I am looking at it from the other side where any photon of light sent out by our probe space ship at that location would exactly run out of energy as it reaches us. I suppose you could say the red shift would be infinite for electromagnetic radiation departing that boundary. And I guess any photon we emit from our vantage point would become infinitely high in frequency as it approached that location. This sounds like a singularity since we know that it is not possible for a photon to obtain an infinite amount of energy in a finite amount of time. The suggestion is that time must be slowed down from our perspective of the ship as it approaches that boundary.
I am hoping to establish that there exists a boundary from which an object becomes invisible to us once it is crossed. Dave -----Original Message----- From: Craig <[email protected]> To: vortex-l <[email protected]> Sent: Wed, Dec 26, 2012 5:56 pm Subject: Re: [Vo]:[OT]:Question About Event Horizon Isn't it a calculated location? Isn't it the radius from the center of the black hole at which a theoretical object at a great distance would reach the speed of light when falling into the black hole from its gravity? Craig On 12/26/2012 04:57 PM, Jeff Berkowitz wrote: I read all the relevant wikipedia pages. My conclusion is that this question is very difficult and that the process of answering it will involve rephrasing it in more precise terms. In particular the term "event horizon" is a catchall for multiple distinct "horizons", each backed by a subtly different mathematical formalism. Jeff On Wed, Dec 26, 2012 at 9:20 AM, David Roberson <[email protected]> wrote: Is the event horizon of a black hole considered an observer relative location? We, who are at a very large distance relative to a black hole see the event horizon as located a finite distance from the center of the star. If another observer happens to be closer to the same hole, does he detect it as somewhat nearer to the center of the hole? I have an interesting thought experiment that depends upon the answer to this question. My suspicion is that the perceived horizon location does depend upon the exact location and most likely motion of the observer. Has anyone had an opportunity to actually calculate this effect? Dave
