Space expansion in our perspective?

Ich

Not correct. As I said, the concept of velocity is not well defined on large scales. Additionally, the very definition of "recession velocity" is (neglecting gravitation) that of a rapidity, not a velocity.
In arbitrary coordinate systems, velocities are arbitrary, too. That has nothing to do with the usual meaning of "FTL travel", which is defined in standard SR coordinates.

benk99nenm312

As I said, fabric is merely a descriptive word, an adjective to describe a slice of our 4 Dimensional Spacetime. Call it what you want, but hey, nearly every theory in existence attributes properties to this cross section of Spacetime. Relativity says that spacetime is affected by mass and energy, QFT gives empty spacetime (the vaccuum) energy and energy density. The way we describe the 'fabric' of spacetime certainly affects reality, and no more will I argue this point.

Utterly, as of what we know, false.

Finally we reach the correct conclusion. Thank you Ich.

powerplayer

ok, so did the term "space expansion" come from the fact that mathematically describing the motion of galaxies worked better in an expanding coordinate system?

Is there physical evidence that space is expanding or is it just a result of the math?

Why is this? Relitivity?

Ich

I think so. In these coordinates, if you calculate the expression for "change in proper distance", you get a very simple and suggestive formula. Like "recession = motion of space + motion through space". This took a life on its own, it seems.
There is ample evidence for redshift being more or less proportional to distance. Which means that the universe may be described well as objects more or less at rest in an expanding coordinate system. I don't know how that pertains to evidence for "expanding space".
Yes.
For example, in special relativity you may have heard that it's tricky to add velocities that different observervers heve measured. In cosmological coordinates, you add them without correction nonetheless. That's easy and appropriate, but the result definitely has nothing to do with "velocity" in the SR sense. Especially, v<c does not apply. That's just the effect of an unusual coordinate system.
Then, in GR, matter determines geometry. You don't even have that static background on which to base your misunderstandings. Is distance changing, or is the light we took to measure distance delayed by some matter that intervened? There's not way to decide such questions.

powerplayer

Thank you Ich.

My curiosity is temporarily satisfied. :)

Chronos

Expansion is a pathetically weak 'force' compared to the other forces of nature - gravity, nuclear and electroweak. It is overwhelmed by these forces until until things become so vastly distant their effects become negligible.

benk99nenm312

Nobody knows the correct answer to this question....