Earlier quoted context omitted.
If spacetime rotates, does that imply there being a centre of the universe?
And an axis.
Or an axis.
Can rotation solve the Hubble Puzzle?
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Re: Can rotation solve the Hubble Puzzle?
#52Universe is called universe because it is the only one. Everything that exists should be part of the universe. When we say the universe rotates, what does it mean? Rotate relative to what? Does it mean that there's a larger "universe" that contains ours?
“Universe” is often used in the sense of “observable universe”.
Re: Can rotation solve the Hubble Puzzle?
#53“We show that a Gödel inspired slowly rotating dark-fluid variant of the concordance model resolves this tension…” Gödel wait what? I thought of him as “only” the logician who killed Hiblert’s dreams and caused people to question the very foundations of mathematics. Dude then took up physics as a hobby and trolled Einstein by discovering closed time-like curves?
At the level of what he did, physics is “just” math (finding solutions for Einstein’s general-relativity equations).
Also, from Wikipedia: “At age 18 [so around 1924], Gödel joined his brother at the University of Vienna. He had already mastered university-level mathematics. Although initially intending to study theoretical physics [we can assume that’d include an interest in relativity at that time], he also attended courses on mathematics and philosophy.”
Re: Can rotation solve the Hubble Puzzle?
#54Earlier quoted context omitted.
I looked around (Smithsonian, space.com, astronomy.com, etc.), but nowhere has any mention of people disputing the findings, do you have a link? Who is "people" in this case? (I was/am skeptical just because it's a single-author study with pretty spectacular results, and have been keeping an eye out for any followups, but must have missed them)
This comment has a good summary of the debunking: https://news.ycombinator.com/item?id=43540635 It's unfortunately rare for this kind of straightforward falsification to make it into publications aimed at the general reader. "A lie is halfway round the world before the truth has got its boots on," as they say.
Do you mean "common" rather than "rare"?
Re: Can rotation solve the Hubble Puzzle?
#55Earlier quoted context omitted.
Rotation implies a great many observables and properties of the universe. There would be a cosmic axis, which implies a cosmic center and a cosmic north. Both concepts that are problematic in an infinite universe. If the universe is in fact inside of a black hole of a different universe - some of these problems go away as the Hubble volume would be the finite boundary of the universe.
Are we in an infinite universe? I thought the current thinking was that it was finite but unbounded; that is, that it curved back on itself.
The observable universe measures as flat, as far as we are able to tell. The universe may be curved overall, but the patch we can see doesn’t let us deduce that, so far.
Re: Can rotation solve the Hubble Puzzle?
#56Earlier quoted context omitted.
Rotation implies a great many observables and properties of the universe. There would be a cosmic axis, which implies a cosmic center and a cosmic north. Both concepts that are problematic in an infinite universe. If the universe is in fact inside of a black hole of a different universe - some of these problems go away as the Hubble volume would be the finite boundary of the universe.
and we would be at the center?
The center of a black hole lies in the future. It’s called a singularity, and the equations of general relativity break down at it. So no, we are not at the center.
Re: Can rotation solve the Hubble Puzzle?
#57> All objects within our universe rotate, including planets, stars, solar systems, galaxies, and galaxy clusters. Moreover, black holes, spherically symmetric objects with horizons, display near maximal rotation as presented by Daly (2019). The idea that everything revolves [...] naturally extends to the whole universe, as hinted by recent claims of anisotropic Hubble expansion in X-ray observations by Migkas et al.…
If spacetime rotates, does that imply there being a centre of the universe?
Depends what you mean by centre, I guess.
If you have two stars orbiting each other, they orbit a centre of gravity and they will probably both be rotating in the same direction as their orbits.
Is that a meaningful centre for anything else though?
Re: Can rotation solve the Hubble Puzzle?
#58Universe is called universe because it is the only one. Everything that exists should be part of the universe. When we say the universe rotates, what does it mean? Rotate relative to what? Does it mean that there's a larger "universe" that contains ours?
Rotation isn't relative. You can tell how quickly you're rotating without reference to any other objects.
Re: Can rotation solve the Hubble Puzzle?
#59If your paper has a question title, it should be sent back to you with the note "change the title to summarize the paper".
And Betteridge's Law applies, so based on this alone: the Universe does not rotate.
Re: Can rotation solve the Hubble Puzzle?
#60Earlier quoted context omitted.
This comment has a good summary of the debunking: https://news.ycombinator.com/item?id=43540635 It's unfortunately rare for this kind of straightforward falsification to make it into publications aimed at the general reader. "A lie is halfway round the world before the truth has got its boots on," as they say.
Thanks. I was hoping for something a bit more authoritative than a reddit comment being copy/pasted to HN (e.g. an actual retraction, or a paper directly disputing the findings), but I'm guessing most of the community just ignored the paper due to the history of the author.
That comment has exactly what you're asking for: Links to papers that show there is no evidence for rotation asymmetry. The very first article linked in that Reddit comment is a scientific publication from the Royal Society with the title "No evidence for anisotropy in galaxy spin directions".