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> All objects within our universe rotate, including planets, stars, solar systems, galaxies, and galaxy clusters. Moreover, black holes, spherically symmetric o
by est31 1y ago
> 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. (2021). Furthermore, a plausible syllogism is that the universe has near-maximal rotation, motivated by cosmologies where the universe is the interior of a black hole (Pathria 1972).
- BigParm 1y agoIf spacetime rotates, does that imply there being a centre of the universe?
- layer8 1y agoIf the universe is the interior of a black hole, one would assume so.
- irrational 1y agoAnd an axis.
- layer8 1y agoOr an axis.
- signalToNose 1y agoAnd my ax
- gitaarik 1y agohttps://en.m.wikipedia.org/wiki/Axis_of_evil_(cosmology) https://en.m.wikipedia.org/wiki/Axis_of_evil_(cosmology)
- pmontra 1y agoWouldn't the center be the Big Bang and the 3D Universe at the current time (if Relativity lets me write about a current time) be the 3D surface of the 4D sphere (or spheroid) that the Big Bang is creating by keeping to expand?
- eggn00dles 1y agothe big bang happened everywhere
- defrost 1y agoWith the caveat that by some awkward metric 'everywhere' was much smaller when it happened.
- gitaarik 1y agoWell, that depends whether the universe is infinite. In any case, everything was closer together and hotter.
- defrost 1y agoInfinities come with a spectrum, some are smaller than others . . .
- s1artibartfast 1y agoand some universes are finite.
- nitwit005 1y agoIt's more correct to just say location had no meaning until something existed in the universe. There's really no way to know if there was something in existence before the big bang however. We just lack evidence of such a thing.
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- olddustytrail 1y agoDepends 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?
- sandworm101 1y agoThere is. The center of the observable universe is earth. Every alien civilization will see themselves at the center of thier observable universe. And each will observe the same rotation in faraway objects. Relativity makes things strange.
- altcognito 1y agoIf everything started from a singularity that had a axiomatically uniform rotation, you might not be able to assess the center "axis" based from inside spacetime itself
- tatjam 1y agoThis seems to be a variation of Mach's principle, which is one of the closest things to philosophy in physics! To say that the universe rotates usually implies that it rotates with respect to something external. If we limit ourselves to the visible universe, this would mean that mass outside our light cones can actually influence us, by means of building the frame of reference that allows us to say that the universe rotates!
- jfengel 1y agoYou don't need any external reference points to know that you're rotating. You could detect it by the apparent centrifugal force: objects in your own frame of reference don't move in straight lines. It would imply that there exist privileged reference points within the universe, and that would be a major change to physics. I can't predict all of the consequences of that, and they might include some kind of external frame of reference. But that doesn't necessarily follow.
- jfengel 1y agoYes, it would. Or at least a central axis. Which would undercut practically all of modern physics. Really fundamental conservation laws like momentum and energy rely on the universe being equal in all directions. If it has a central axis, that does not hold. So if that holds, it's potentially a major pointer to the very origins of the universe itself. But it's also one of those extraordinary claims that require extraordinary proof. I strongly doubt that this will stand up to scrutiny -- though I'll certainly be pleased if it turns out be true, because that will be a major advance in our understanding.
- cryptonector 1y ago> a plausible syllogism is that the universe has near-maximal rotation And also from the abstract: > Curiously, this is close to the maximal rotation, avoiding closed time-like loops with a tangential velocity less than the speed of light at the horizon. That's weird considering that in lambda CDM the universe's accelerating expansion implies that stuff falls out of our observable universe, which implies that there is more stuff beyond the edge of the observable universe, and anyways there is no center of the universe and we are only at the center of our observable universe, which also further implies that there is stuff beyond the observable universe. Are they saying that our observable universe has a rate of rotation such that the tangential velocity at the edge is about the speed of light? What about the stuff beyond the edge? And as u/BigParm wonders, doesn't having the whole universe rotate imply a center? Surely we can't be at that center. But maybe there can be an illusion that we are at the center of rotation.
- ano-ther 1y agoIf the universe is a black hole, would we be able to see anything falling into it after it crosses the event horizon?
- consp 1y agoYou must be able to observe the edge to see that. And afaik the scientific community agrees no edge is observable in our cone of light.
- mcswell 1y agoAs I got right up against the wall, I noticed the little white square sign. It said, "Obviously you are not convinced that this is the end of the universe. if you will place a quarter in the slot below, the peep-hole will open, and you can see for yourself." And the captain was right. I paid my quarter and looked through the peep-hole. But it was nothing. --From "Ado about Nothing, by Robert K. Ottum
- ashoeafoot 1y agoSo everything that ever fell into the blackhole arrives into the big bang at the start?