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] > <mailto:[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 > >
