John Helly's latest activity

@John Helly you might find this helpful: https://www.physicsforums.com/insights/balloon-analogy-good-bad-ugly/

jbriggs444 What you describe is difficult to envisage for the layman who can't to do the math to understand it that way. But through...

You can't make this statement without specifying a coordinate chart. There is no such thing as "moving" or "not moving" in any absolute...

Not really no. The viewpoint that "nothing is moving through space, but space itself is expanding", and the viewpoint that "objects are...

Yes, when @jbriggs444 said "nothing is moving", he was (implicitly) using a comoving coordinate system. That's the most common...

How about 'Light takes longer to travel between them'?

That's an invariant which is due to the invariant expansion scalar, yes.

The simplest mathematical example that illustrates an infinite universe is the number line. With 0 in the middle (although...

Ok. The 1D example is helpful. Is there a place in the literature I can start to find the math that underlies this? I would like to...

I interpret this as analogous to 'zooming' a view in an image. The coordinates are not changing but user's viewport is.

Mahalo. I will have to ponder this for a while.

Ah.

Ok. But what was expanding, then, and still is? Must be some kind of domain? Excuse me, I'm an earth scientist trying to wrap my head...

Mahalo. I will read the link.

What scale factor? What is being scaled if the domain is infinite?