Is the speed of light constant between galaxies?

I'm trying to form an opinion of whether such a thing is possible. But I don't think reading speculation built on more speculation all stated as fact is going to help decide.If you want to convince me, at least, you're probably going to need some math based predictions that flow from your speculation. A good place to start would be showing me how distorted images can be undistorted by gravitational lensing. Your assertion that computer look better than real in a mirror was not the least bit helpful.

But I think something is missing there.I was questioning the meaning of "constant speed".As I see it, the constancy of the speed of light is used as a sort of standardizing principle, so as to find ways of translating measuring scales between different inertial frames. It is unlikely that the OP was asking about standardizing principles. So I wanted to know what he thought he was asking about.

I don't think that is the case here (unless I am misunderstanding you).Photons are not like bullets. People in different inertial frames would measure a different speed for a bullet. Not so with light. The speed of light is measured as being the same in all inertial frames. It isn't standardized to be the same. It IS the same.

Oh. I can see that. I are just so good at comoo ... commo ... at reading.You are right, however. "c" is about as constant as you can get. Because c is constant in a vaccuum, everywhere, at all times, from every frame, it does let us build the needed transformations between units is differing systems. Whether we measure in kilometers per second or pinars per mosax we will achieve the same value when the units are properly transformed.What the OP seems to be missing is that light follows the spacetime curvature created by the presence of matter whether normal or dark. Everything follows that same path, even neutrinos, just not as fast as photons.I think he is trying to take the concept behind gravitational lensing to an unevidenced extreme.Edited by AZPaul3, : I will now stop second gussing my proofreading leave this as it is warts and all.

No, not true. And that is why there is an element of the actual physics/mathematics (accidental or not) in his musings. Photons do not follow the same path through space-time as massive objects - the former follow null-paths and the latter, time-like paths. These can be quite different, especially where curvature is high (good example is the null orbit around a Schwarschild black hole at r=3M.)

I yield to the details.

As i see it, light behaves in certain ways, as the Double Slit experiement shows,
So when light comes into contact with dark matter, it becomes both a wave and a particle, the wave is bent around the dark matter, which we see as gravitational lensing,
but the particle will go through the dark matter, but will also leave our frame of reference,
follow the particle and its speed would not change, only the space it travels through,
it would eventually pass through dark matter, we would see this first as a red or blue shift as it slowly emerges(from our perspective), and continues on it way,
Never knowing it had passed through any medium,
where as the wave had passed around the dark matter thousands, millions, or billions of years before, depending upon the mass of the dark matter.Edited by sunshaker, : No reason given.

Thats the wonder of higher d space(dark matter), its as it own time and space.Edited by sunshaker, : No reason given.

I'm not sure how relevant this is to what you’re asking, but I heard there was work being done on making a map of the universe with the relative time worked out to show a picture of what the universe looks like at one specific moment in time.Not sure about much of those details, but pictures of galaxies or looking into the sky we see old light, and the old position of the emitter.

Sorry NoNukes, i am afraid the math, will have to be left to those who have a "math mind",
i understand some math, but not enough, i am an ideas man, i read all i can find on many subjects, and from many great scientists and mathematicians who have spent there lives working on certain pieces of the bigger picture,
We can now take all these pieces and put them together,
We all have our part to play,
All i put forward is how i have put these pieces together, this is just a small part of the picture which i am interested in at the moment,
You could spend your whole life looking at the mechanics of a "piston" and never see the "engine" or the "vechicle" that engine belongs to, or what the purpose of the vechicle is.As for looking at your computer screen in a mirror, i was just trying to say that sometimes looking at something by direct sight does not always give you the best image.I cannot find anything that does not fit into how i see our local universe and beyond.

Just thought i would add a little more on what will occur again in our distant future, on the life of our local universe,
As i have said "all matter and energies" both common and dark dropped through into this lower dimensional space, and rapidly expanded, still expanding, but also falling,
This expanding of "dark matter" produces all the building blocks of the matter and energies we can now see or detect,
At the moment we are in a universe bubble made of "dark matter", now full of pockets of this lower d space,
As we continue to fall and expand dark matter will eventually be no more it will be transformed into common matter, the universe bubble will be no more, but all matter and energies will continnue to fall, in this lower d space,All this matter(planets stars, most long dead) eventually "settle", where other "gravitational forces" take hold, and start clumpping this matter together again, forming what i call the "Omega" consisting of all that as ever been,
Once again, this "Omega",
Others may call it "The God Particle" or some "The Higgs Boson", Will become too massive for this dimension and fall through yet again into lower d space, and rapidly expand, And it all begins again.
As i read somewhere exsistance from non exsistance.Edited by sunshaker, : No reason given.Edited by sunshaker, : No reason given.

And you know this how?

Why should I accept that model over, say, this one: Any reason?

Because i know what the "vechicle" is and the purpose of said "vechicle", but that is to far beyond this, that is why for now i am looking at the workings of the "piston".
And try to stick to what can be proved,Perhaps i might not have the math, but i know how it all fits together.
I just want to tidy up a few lose ends.
All you see is not what you believe it to be.If i was to say "how" i would not be believed, and this would be the wrong kind of thread.
I am only saying what i see, and know to be true.Feel free to disprove me.

I thought the path followed by both matter and energy simply followed the curved shape of space - light doesn't?--Percy