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John Helly's latest activity
J
John Helly
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phinds's post
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Where did the early photons go?
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@John Helly you might find this helpful: https://www.physicsforums.com/insights/balloon-analogy-good-bad-ugly/
Today, 2:08 AM
J
John Helly
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Cerenkov's post
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Where did the early photons go?
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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...
Today, 2:08 AM
J
John Helly
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PeterDonis's post
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Where did the early photons go?
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You can't make this statement without specifying a coordinate chart. There is no such thing as "moving" or "not moving" in any absolute...
Today, 2:08 AM
J
John Helly
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PeterDonis's post
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Where did the early photons go?
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Not really no. The viewpoint that "nothing is moving through space, but space itself is expanding", and the viewpoint that "objects are...
Today, 2:08 AM
J
John Helly
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PeterDonis's post
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Where did the early photons go?
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Yes, when @jbriggs444 said "nothing is moving", he was (implicitly) using a comoving coordinate system. That's the most common...
Today, 2:08 AM
J
John Helly
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DaveC426913's post
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Where did the early photons go?
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How about 'Light takes longer to travel between them'?
Today, 2:08 AM
J
John Helly
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PeterDonis's post
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Where did the early photons go?
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That's an invariant which is due to the invariant expansion scalar, yes.
Today, 2:08 AM
J
John Helly
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PeroK's post
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Where did the early photons go?
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The simplest mathematical example that illustrates an infinite universe is the number line. With 0 in the middle (although...
Today, 2:07 AM
J
John Helly
replied to the thread
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Where did the early photons go?
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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...
Today, 2:05 AM
J
John Helly
replied to the thread
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Where did the early photons go?
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I interpret this as analogous to 'zooming' a view in an image. The coordinates are not changing but user's viewport is.
Today, 1:48 AM
J
John Helly
replied to the thread
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Where did the early photons go?
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Mahalo. I will have to ponder this for a while.
Today, 1:38 AM
J
John Helly
replied to the thread
I
Where did the early photons go?
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Ah.
Yesterday, 2:16 PM
J
John Helly
replied to the thread
I
Where did the early photons go?
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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...
Yesterday, 2:14 PM
J
John Helly
replied to the thread
I
Where did the early photons go?
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Mahalo. I will read the link.
Yesterday, 2:12 PM
J
John Helly
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Where did the early photons go?
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What scale factor? What is being scaled if the domain is infinite?
Yesterday, 2:07 PM
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