I think a lot of the reasoning about photons, above, is wrong. The red shift has nothing to do with gravity, only the relative velocity of the photon source relative to the observer. If an event just outside the event horizon of a black hole emits a photon, an observer at rest relative to the black hole will observe no red shift regardless the strength of the black hole's gravitational field. If the observer then accelerates away from the black hole, similar photons emitted from the same source will appear to be red shifted. It's entirely an observational effect. There is no loss of energy from the photon and no need to store anything anywhere.
Jeff On Thu, Dec 27, 2012 at 9:21 PM, Abd ul-Rahman Lomax <a...@lomaxdesign.com>wrote: > At 10:16 PM 12/27/2012, David Roberson wrote: > > >>That energy leaving the massive star becomes trapped within the >> >>space surrounding it to a significant degree; how is this possible >> >>unless space itself has expanded to accommodate it? >> >> >No, the energy is not trapped. Light continues to travel at the speed of >> light. >> >> Actually Abd, a photon has a finite amount of energy that is directly >> proportional to its frequency. >> > > Yes. > > > If it becomes red shifted by definition it has less energy. Since the >> photon looses energy as it travels through the region from the edge of the >> black hole toward our observation point, that energy must be stored within >> this space. >> > > The energy is stored in the gravitational system. It is potential energy. > When a body falls toward the earth, its potential energy is converted to > kinetic energy. When the body is shot from the earth, and it is > deaccelerated by gravity, its kinetic energy is converted to potential > energy. > > We don't normally think of light this way. However that seems to me to be > what happens. If the light were reflected back to the black hole, returning > along the same path, it would regain the energy it lost. Potential energy > is converted back to kinetic energy. > > > We could collect each photon with a detector after it leaved the vicinity >> of the black hole and we would find that it is less energetic. So no, it >> does not continue forever at the same energy. >> > > That's correct. But it continues forever, unless it is obstructed. And it > continues at the same velocity. It does not slow down (in a vacuum, anyway). > > > > > >Then the photon will continue to infinity. I thought that your idea >> >was supposed to be a way to communicate information from within the >> >event horizon to outside, by positing a ship that is outside of our >> >horizon, but sees an event horizon closer, and the second ship is >> >within our horizon -- we can't communicate with it -- but outside of >> >the first ship's horizon. >> >> One thing at a time Abd. The main plan is to communicate if possible, >> but this explains part of the problem and why it happens. Every once in a >> while it makes sense to look at the overall system. >> >> >It's like any photon. It travels until it reaches the end of time. >> >I.e., forever, and a day. Its energy remains intact, but because of >> >the red-shift, the energy is spread out more. >> >> No. If the photon becomes red shifted, energy is lost from that photon. >> If the red shift is total down to zero, no energy remains. >> > > If the photon is beyond the event horizon, heading outward, it is never > red shifted to "zero." (I was incorrect about energy, though. Energy is > lost in climbing the gravitational well, stored as potential energy from > gravity.) > > > > >What do we have in terms of observation of black holes? >> >> Sorry if it sounded like I had observations of them. I was just asking >> if others might as I do not. >> > > I didn't think that. > > > > >It has to be. However, I don't know that any such object has been >> >observed. All the spectral lines would be shifted. We might conclude >> >that the object is a a great distance, and the only way we'd know >> >that it wasn't would be if we could detect graviational effects other >> >than red shift. >> >> This is a good question for the astronomers. Perhaps they are seeing >> these things and are not aware of it. It is hard to imagine that there are >> not a large number of these out there unless they tend to explode before >> reaching this size range. >> >> It might not be a bad idea for the astronomers to take a second look at >> what is referred to as failed stars or other unusual thermal objects. >> > > I doubt they would miss this. But maybe. > >
