101–110 of 120 posts
Is this a reasonable conclusion?
Earlier 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.
Do you mean "common" rather than "rare"?
I meant the rebuttal usually doesn't get published with the same high profile as the original story.
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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.
It's only been a finite time since the universe was very small, so unless it's expanding infinitely fast, I don't see how it could be infinite
> 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?
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!
based on napkin math, the rotation they land on: 4.34 x 10^-20 rad/s is one order of magnitude (not a lot on a cosmological scale) slower than necessary for a causal disconnect at the boundary of the observable universe due to tangential velocity (at ~C) - obviously my maths could be off-by-one. Is this a reasonable conclusion?
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Nitpick: atoms really have no subdivisible parts with the same properties as the whole . They are aptly named.
Atoms having no subdivisible parts implies that there are parts at all. But it turns out all matter is just somewhat stable oscillations within an energy field and no real boundaries between one part and another, and certainly nothing resembling such at the scale of something as large as an atom. So again.. too early..
> 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.…
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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…
> 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?
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.
Earlier quoted context omitted.
If spacetime rotates, does that imply there being a centre of the universe?
This 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…
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.