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Can rotation solve the Hubble Puzzle?

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Re: Can rotation solve the Hubble Puzzle?

#91

Post by Certhas »

nitwit005 wrote: post #77
eggn00dles wrote: post #68

Earlier quoted context omitted.

the big bang happened everywhere

It'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.

I think "the big bang happened everywhere" is more correct than your take. The big bang dlrefers to the early period of a spacetime with an initial moment. At that initial moment the distance between all points is zero. But there still are a full 3d set of locations. Starting at this initial moment, distances between points grow quickly. Thats the bang.

It is true that in GR you can't speak of "before" the big bang, but the big bang itself is a feature within time. It happens at the first moments of time and everywhere in space. And if you replace the initial singularity with a dense quantum foam and thus are able to extend time into the past in some quantum sense, the big bang doesn't go away.

Re: Can rotation solve the Hubble Puzzle?

#92

Post by ForOldHack »

roarkeful wrote: post #42
bostonwalker wrote: post #6

I seem to recall there was an article posted here recently which noted that galaxies have a preferred direction of rotation. Seems like the universe itself rotating could be a reason why?

The universe being a giant toilet in the process of flushing is delightfully Doug Adams inspired.

It's that constant sucking sound ...

Re: Can rotation solve the Hubble Puzzle?

#93

Post by ForOldHack »

jl6 wrote: post #12
AnimalMuppet wrote: post #11

Earlier quoted context omitted.

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.

That’s one speculative possibility, but we don’t know. It could be infinite, or finite with a boundary just out of sight (beyond the edge of the observable universe), or some other more exotic geometry. There’s no solid evidence either way. My money’s on non-infinite, just because I’m not sure infinity is a well-defined concept outside of mathematics. We’ve certainly never observed any other infinite phenomena.

My money is on Joe Haldmans sawtooth cosmogony. Build an accelerator to simulate the big bang... Instead it recreates it.

Re: Can rotation solve the Hubble Puzzle?

#94

Post by ForOldHack »

jl6 wrote: post #12
AnimalMuppet wrote: post #11

Earlier quoted context omitted.

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.

That’s one speculative possibility, but we don’t know. It could be infinite, or finite with a boundary just out of sight (beyond the edge of the observable universe), or some other more exotic geometry. There’s no solid evidence either way. My money’s on non-infinite, just because I’m not sure infinity is a well-defined concept outside of mathematics. We’ve certainly never observed any other infinite phenomena.

I want to address this specific comment: "or some other exotic geometry..." And ask conceiveavle or inconceivable? Of conceiveable by future beings? Far future beings? Current sci-fi authors? My uncle Ian? Only Joe Haldman?

Re: Can rotation solve the Hubble Puzzle?

#96

Post by s1artibartfast »

defrost wrote: post #85
gitaarik wrote: post #82

Earlier quoted context omitted.

Well, that depends whether the universe is infinite. In any case, everything was closer together and hotter.

Infinities come with a spectrum, some are smaller than others . . .

and some universes are finite.

Re: Can rotation solve the Hubble Puzzle?

#97

Post by Nevermark »

tsimionescu wrote: post #78
Nevermark wrote: post #30

Earlier quoted context omitted.

Imagine that at some small distance, space itself is quantum, so quantized. I.e. at the bottom, space is a discrete graph with incredibly small edges. Possibly very tangled and not even layed out in obvious dimensions over short distances. We don’t know if that is the case. That is only one possibility. But it seems very clear that whatever happens at the Planck distance or lower isn’t simple smooth space as we model…

Unfortunately for this idea, special relativity tells us that Planck length is an observer-dependent phenomenon. That is two objects that are at a distance that is more than the Planck length apart for one observer will be closer than the Planck length for another observer and vice versa. So Planck length can't be a fundamental property of space-time, unless special relativity breaks down at some point even for non-a…

I would suspect since general relativity would break down that special relativity certainly would.

The “relativity” aspect will almost certainly still apply in some way, and still form an emergent basis for the special relativity effects you point out.

All of general relativity has to be emergent from the to-be-discovered laws of the underlying small scale structure of space.

(I.e. general relativity isn’t wrong, it is just not complete. Similar relationship as with Newton’s Law of Gravity, which was also correct, but breaks down beyond the conditions it covers well, because it was not complete.)

The smallest scale is also where we expect more “light” shed on the initial conditions of the universe and potentially the insides of black holes. Two other conditions where general relativity already breaks down.

Re: Can rotation solve the Hubble Puzzle?

#98

Post by consp »

ano-ther wrote: post #87
est31 wrote: post #4

> 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 the universe is a black hole, would we be able to see anything falling into it after it crosses the event horizon?

You 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.

Re: Can rotation solve the Hubble Puzzle?

#99

Post by quickthrower4b6 »

analog31 wrote: post #73
natch wrote: post #70

Rotation relative to what?

I consider this to be a good question, but with a reasonably familiar answer: Rotation is absolute. Unlike linear motion, you can tell if you're sitting in a rotating frame of reference or not. Experiments such as the Coriolis force, and Foucault's pendulum, are demonstrations of this principle. In fact, a historical oddity is that when this idea was nailed down by both theory and experiment, the Catholic Church drop…

[dead]

Re: Can rotation solve the Hubble Puzzle?

#100

Post by carra »

olddustytrail wrote: post #58
jinwoo68 wrote: post #47

Universe 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.

But even then you can only tell that you are rotating relative to space itself. If I understand correctly here we are speaking about the space itself rotating, so that would not be possible unless something else contains our universe's space, right?
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