Is the speed of light constant between galaxies?

Based on what evidence?

Where are the experiments and observations that show this?From everything I have read, dark matter is supposed to have no charge.

To add another point,As i see all matter and energies as being "higher dimensional" and the space we are expanding into as lower dimensional,So matter is always trying to fall in to its centre, collapsing in on its self, trying to get back to the higher d space, The energies that have been formed since the expansion electro magnetic forces-electrons are trying to expand everything, this creates opposeing forces, and a balance is found, this gives matter form.But it is only when there is enough mass of matter "The Omega" that it can tip the balance and collapse "fold" back into the higher dimension once again.

It is the expansion of dark matter that gives the charge.
Hydrogen H Discovery of H2 in Space Explains Dark Matter and RedshiftEdited by sunshaker, : No reason given.

Ah, it's Paul Marmet again.The reference you cite speculates that Dark Matter is simply molecular hydrogen, i.e. ordinary hydrogen gas. I don't see any support whatsoever for what you say at this link.Further, you are proposing that the expansion of space would cause hydrogen molecules or hydrogen atoms to become ionized. Do you have any understanding how little expansion of space would be present within the distance of an electron in a hydrogen atom. An electron could never be freed from an atom by the expansion of space. At least not before the 'Big Rip'.Find a new proposal. Please.

I can find some articles and references that discuss the possibility that dark matter is charged. Is dark matter a wimp or a champReopening the window on charged dark matter

This fails on several fronts. First, hydrogen interacts with light. Dark matter does not. Second, your cite is arguing for a tired-light hypothesis which has already been falsified:http://www.astro.ucla.edu/~wright/tiredlit.htmI mentioned Compton scattering before, and it applies to other non-doppler redshifts. These mechanisms scatter light. This will result in either an opaque universe or a universe where distant galaxies are very blurry. We don't observe either. Therefore, dark matter can not be ions, and the observed redshift can not be due to photons interacting with hydrogen or ions.

You can see the Moon being made of green cheese, but that doesn't turn the Moon into green cheese. You need to supply evidence for your claims instead of just stating "I believe".

As you may see i edited the link in on "hydrogen h" by paul marmet,
as somewhat of an after thought, as i found this part interesting, " In the case of molecular hydrogen, there is no dipole moment, so that no radiation can be absorbed or emitted".But also what i am saying "dark matter" is higher dimensional space, can you comprehend distance within this space, the distance of an electron in a hydrogen atom within this space would no longer apply,This dark energy is our universe, the space between is the "lower dimensional space" that fills our expanding universe, all matter and energies we see has its source from within this dark matter,All matter and energies are the result of the continuing expansion, the stretching of this "dark matter" by lower d space, Many continuous "Big Rips", These energies are then deposited by lower d space in pockets creating gravity wells, where stars/galaxies form.I see more of protons and neutrons closely packed together, being split between higher and lower space.I was watching about the tsunami in japan and could not help but think, how the water that washed through the citys, picking up cars and buildings and depositing all this rubble, reminded me of how lower d space worked,
Rushing into our universe washing through and around dark matter, expanding space, stretching dark matter, creating energies,depositing these energies, in pockets of lower d space. Edited by sunshaker, : Tsunami

Just a thought on your link http://www.astro.ucla.edu/~wright/tiredlit.htm Where it states,"There is no known interaction that can degrade a photon's energy without also changing its momentum, which leads to a blurring of distant objects which is not observed".If like i mentioned earlier that we cannot really tell where anything is as light is always bending around dark matter, and other galaxies, could this refocus the blurring of said given objects.if you turn and look at your pc monitor in a mirror you will see a sharper more colourful screen.only a thought.

For all other objects this is correct.But, Einstein's great insight was that this is in fact not the case for light.Every frame of reference will measure the same speed of light in a vaccuum and there is only the one value that can be measured for that speed all regardless of any frame. Edited by AZPaul3, : clarity - I hope

I think we can get to tied done in explainning the properties of dark matter, these properties are forever changing the more our universe expands, and will continnue changing,
dark matter expands with the expanding universe, when the expansion first began all matter and energies where compressed , from "our perspective" a tiny finite size,
The first stage of rapid expansion created most of what we now see as matter and energies,
as we continnue to expand the properties of dark matter change, whether we call these expanded particles, nucleons, ions, or hydrogen h,
Different parts of the expansion will have different properties,But one thing most agree on is that there is something that most call "dark matter" that effects any direct observation, and can only be detected through the effects of gravitational lensing,So like i asked before is it possible that nothing we see is where we believe it to be, if light as to travel around all these gravity fields, before reaching us?

No. There is no putting Humpty Dumpty back together again. Once light is scattered you can not realign it. Sandblast the mirror to a dull finish and then look at the reflection. That is a scattered image.

You can say that the moon is made of cheese, but that doesn't make it true. What we need to see is actual evidence for your claims.

Dark matter certainly can't be ions as we have already discussed.Also, it appears that dark matter can not be hydrogen either. Scientists found two galaxy clusters in the midst of a collision. What they found is that the luminous matter interacted and slowed during the collision. However, there was matter that did not absorb or emit light, and it sailed right past without interacting like normal matter would. APOD: 2006 August 24 - The Matter of the Bullet Cluster The only type of interaction that dark matter has with normal matter is through gravity. That is inconsistent with hydrogen which would interact with other molecules or atoms of hydrogen, and would emit light at those temperatures.