There are some pretty smart people who disagree with you. They think the speed of light might be determined by the texture of the space-time that the light has to cross.Chronos said:Given the speed of light is invariant, the relative motion of galaxies in the foreground is of no consequence. Only mass need be considered for lensing effects.
Granted that if the first early galaxies were moving very slowly with respect to light, then lensing would not be affected by the motion of the foreground galaxy. But I do not know how fast early galaxies were moving, do you? But if there were moving at some portion of light, say 1/3 that of light, then the backgound photons would feel the force of gravity for a longer period of time and be deflected more. I don't see yet what invariance would have to do with anything. Not only that, but the galaxies would acquire some portion of relativistic mass and the gravitational field associated with that.Chronos said:Given the speed of light is invariant, the relative motion of galaxies in the foreground is of no consequence. Only mass need be considered for lensing effects.
Mike2 said:Granted that if the first early galaxies were moving very slowly with respect to light, then lensing would not be affected by the motion of the foreground galaxy. But I do not know how fast early galaxies were moving, do you? But if there were moving at some portion of light, say 1/3 that of light, then the backgound photons would feel the force of gravity for a longer period of time and be deflected more. I don't see yet what invariance would have to do with anything. Not only that, but the galaxies would acquire some portion of relativistic mass and the gravitational field associated with that.
Galaxies moving slowly with respect to light? Light does not have a preferred reference frame. That is why the speed of light is called 'invariant'. And yes, I do know, given what I have read, how fast galaxies were moving in the past. It is called red shift. Your photon deflection model is not supported. Photons entering a gravitational field are blue shifted. When they exit, they are red shifted. The net effect is... zero.Mike2 said:Granted that if the first early galaxies were moving very slowly with respect to light, then lensing would not be affected by the motion of the foreground galaxy. But I do not know how fast early galaxies were moving, do you? But if there were moving at some portion of light, say 1/3 that of light, then the backgound photons would feel the force of gravity for a longer period of time and be deflected more. I don't see yet what invariance would have to do with anything. Not only that, but the galaxies would acquire some portion of relativistic mass and the gravitational field associated with that.
Really? That is a pretty bold assertion. Which version of aether do you have in mind, Lorentzian?Turbo-1 said:The fact that "empty" space is actually a sea of virtual particles is proof that there is an aether.
It's not bold at all. The vacuum of space is not empty, but is populated by zero-point energy fields. The EM ZPE field consists of a sea of self-annihilating virtual particle pairs, and this field exerts a measurable force, as demonstrated by the Casimir effect.Chronos said:Really? That is a pretty bold assertion. Which version of aether do you have in mind, Lorentzian?
Well, let's see... durring inflation all matter was moving very fast, right? Then the force of gravity slowed matter even while it condensed to galaxies. I still don't know how fast those first galaxies were moving? Or was everything moving very slowly in comoving coordinates even during inflation?selfAdjoint said:Surely the galaxies' own local motions were far less than c, and if you mean motion due to expansion, of course the galaxies were not and are not moving in that sense. Space is expanding, the remote galaxies are no more moving like that than we are.
Agreed. They were moving very slowly in comoving coordinates even during inflation. As selfAdjoint pointed out, there is no evidence to suggest relativistic contributions to the mass of distant galaxies are any greater than for local galaxies [which is insignificant]. Cosmological red shift does not affect relativistic mass. Returning to the question of lensing of the CMBR, which is also relevant, see here.Mike2 said:Well, let's see... durring inflation all matter was moving very fast, right? Then the force of gravity slowed matter even while it condensed to galaxies. I still don't know how fast those first galaxies were moving? Or was everything moving very slowly in comoving coordinates even during inflation?
Agreed. If 'c' is not invariant, a lot of modern theory turns into a mess. On the other hand, there is good evidence that 'c' has not detectably changed for billions of years, if ever [there are some possible anomalies if you go back 12 billion or so years].Wolram said:If DM is cold and dark, how can it be proven, detected, if something most think of as invariable isn't "c" for instance, please forgive my ignorance, but
it seems to me that this is a circular argument.
C may be invariant over time. Time (history) may be irrelevant. C must be variable, however, based on the density of the media through which light propogates (basic optics). If the vacuum of space is not truly a "void", but in fact contains fields defined by the base-level energies predicted by QED (the zero-point energy fields), we must expect that the light propogating through these fields can be effected by the properties of these fields.Chronos said:Agreed. If 'c' is not invariant, a lot of modern theory turns into a mess. On the other hand, there is good evidence that 'c' has not detectably changed for billions of years, if ever [there are some possible anomalies if you go back 12 billion or so years].
This seems to suggest that the CMB is a backdrop farther away than the most distant galaxies? I didn't catch how much farther they assume the CMB to be. Nor did they explain how all this light got that far out? But, then again, they admit that this is only a simulation and that we do not yet possesses the capability to measure the CMB accurately enough to confirm this lensing of the CMB.Chronos said:Returning to the question of lensing of the CMBR, which is also relevant, see here.
http://home.fnal.gov/~scranton/LensedCMB/effect.html
Agreed. The CMB is a backdrop to the most distant galaxies yet observed. The current suspect for most distant observed galaxy is z = 10. The CMB is around z = 1100.Mike2 said:This seems to suggest that the CMB is a backdrop farther away than the most distant galaxies? I didn't catch how much farther they assume the CMB to be. Nor did they explain how all this light got that far out? But, then again, they admit that this is only a simulation and that we do not yet possesses the capability to measure the CMB accurately enough to confirm this lensing of the CMB.
Agreed.Mike2 said:But wait, if the CMB photons were traveling since the beginning without scattering, then the photon that WE receive from the CMB must be the oldest photons of all. The photons from the photon soup that originate at every point and has been redshifted by expansion have photons originating at all points of space, but we only see those that are as old as recombination. CMB photons that were emitted nearer to us at the time of recombination have already past us by and are now headed away from us. We only see the oldest of the CMB. So we are seeing a backdrop. Is this right?
That is just the way it works. You shouldn't believe anything until you can explain it to yourself.Mike2 said:Why does it seem that I have to be the one to explain everything?
Agreed. It's not possible.Mike2 said:What confuses me is if we can see these photons emitted so far away by the CMB, then how can there be any kind of horizon that is closer to us behind which galaxies are disappearing?
Yes.Mike2 said:Or is it that the CMB that we see IS the horizon.
No. It is exactly as cold as it should be given the age of the universe. The CMB photons we now detect had a temperature of about 3000k at the time they were emitted. The only thing that cools them down is red shift. Since they now are about a temperature of 2.75K, we know that recombination occurred at around z = 1100 [which blue shifts them back to the time they had a temperature of about 3000k].Mike2 said:If so, then shouldn't it be even colder, in fact zero?
The CMB will gradually grow cooler and cooler, always approaching but never quite reaching absolute zero. No new galaxies will emerge from behind the CMB barrier.Mike2 said:Or will there come a time when we will no longer see the CMB? Or will the faint, red light of other galaxies take its place as the universe expands?