Uniform redshift in inflationary model?

[toliynyk]

This question might be a result of perceptual ignorance but still:
In explaining an inflationary cosmological model that postulates a prime singularity (i.e. starting with a Big Bang) some tend to associate it with "dots on an inflating balloon". Doesn't this imply that the "dots" that are somewhat farther away from the origin should be separating faster than closer ones? And if so, wouldn't that lead to a non-uniform redshift effect in opposite directions perpendicular to the origin? And then there's the subject of initial velocity of objects of different mass - shouldn't this effect the propagation of matter in such a model, leading to a "lagging behind" of larger matter clusters due to higher inertia?

 

[marcus]

The words people use are often confusing. The standard comology model (since way back----1950 or earlier) has involved EXPANSION.

What you are asking about is not "inflation" (in cosmo that word is technical, reserved for an unproven very special very brief episode of extremely rapid expansion before ordinary objects and ordinary matter existed). The balloon with dots is not used to illustrate the "inflation" episode, as far as I know.

What you are asking about seems to be just ordinary expansion cosmology, that is what the balloon with dots is often used to illustrate.

The kind of questions you are asking about expansion cosmology are similar to ones often discussed in the Cosmology Forum. Hopefully this thread will be moved there, and we can see about answering them.

 

[marcus]

... associate it with "dots on an inflating balloon". Doesn't this imply that the "dots" that are somewhat farther away from the origin should be separating ...

No it does not imply that. The balloon analogy is only a 2D picture of what really happens in 3D, but it is still quite useful so let's think about it!

In the balloon toy model no one dot is the "origin". So it is not possible for some dots to be "farther away" from the origin than other dots.

If you want to understand the balloon analogy better you might try googling "wright balloon model". A professor at UCLA has a cosmology tutorial website and it has a short computer animation you can watch, plus a lot of other goodies.
There is also a balloon model sticky thread here at cosmo forum that you might find helpful.