isn’t counterclockwise same as clockwise whe viewed from the other side?
James Webb Space Telescope reveals that most galaxies rotate clockwise
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Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#222Earlier quoted context omitted.
We're in the centre of the observable universe. The observable universe is the only true sphere. The observable universe is expanding into the unobservable universe. What would be interesting is to run a diff on the cosmic microwave background and the pictures from the James Webb space telescope to figure out where the true centre of the universe is, and derive the poles from there.
> The observable universe is expanding into the unobservable universe. Is that so? My understanding is that it doesn't expend into something. And that it expend so fast that the edge of it becomes unobservable.
Thats just a distinction between the Observable Universe and the Universe. The observable universe should be labeled "Our" Observable Universe as what is observable depends on where you are. Imagine a sphere growing outward at the speed of light, this is what is observable this region is aka the Hubble Volume. Right beyond the edge there just hasn't been enough time for the light to reach our location. No woowoo required.
There are ongoing debates whether the actual Entire Universe is infinite or not.
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#223Potentially a very dumb question, but seeing the difference between cyclones and hurricane on earth (clock-wise, anti-clock-wise)... Does it mean that we are, potentially, on one of two poles(?) of the observable universe, if we're observing most galaxies around us rotating a certain way?
Dumber question: would a galaxy that appears to spin clockwise appear to spin counter-clockwise when viewed from the other side? Does this imply that the real question is why galaxies' relative orientations seem to favor more spinning in one direction than the other?
This is exactly the dumb question I came here to ask. So now I wait with you for a less dumb person to reply.
My clock certainly seems to tick in the opposite direction when I look at it from behind.
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#224But rotation direction depends on the observer. If i see galaxy spinning clockwise, this means someone observing galaxy from behind it sees it rotating counter clockwise. So are we just located so in the universe that we see 2/3 spinning clockwise and another counter?
It just occured to me that "rotation direction" is a pretty coarse measurement. Actually, you could look at the angle of a galaxy relative to ours, where (let's say) 0° is viewed exactly from "above" (rotating clockwise), 180° is viewed exactly from "below" (rotating counterclockwise), 90°/270° is viewed side-on etc. How about some stats based on this parameter?
What does "above" or "below" even mean in the context of something without a top or bottom? Or are you defining "above" to mean "the vantage point from which the galaxy appears to be rotating in the direction of earth clocks" for the purpose of this question?
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#225Potentially a very dumb question, but seeing the difference between cyclones and hurricane on earth (clock-wise, anti-clock-wise)... Does it mean that we are, potentially, on one of two poles(?) of the observable universe, if we're observing most galaxies around us rotating a certain way?
Dumber question: would a galaxy that appears to spin clockwise appear to spin counter-clockwise when viewed from the other side? Does this imply that the real question is why galaxies' relative orientations seem to favor more spinning in one direction than the other?
Yes, that's it exactly. There's a net asymmetry in the distribution of galaxy axes. "Clockwise" by itself is a relative term. This seems to be the paper in question: https://academic.oup.com/mnras/article/538/1/76/8019798
That said: I'd wait a bit here. This is a single-author paper by a non-astronomer (he's a CS professor). The sample size seems small (N=263), and the measurement coarse (he's just bucketing galaxies into "rotating in the same/different direction as the Milky Way"). And the technique may be too novel for its own good. The gold standard here would be to look at differential redshift, but all he's doing is applying a ML filter to detect the "twirl" direction in the image of the spiral galaxy. Which... might be amazingly effective or might fall on its face because of bugs in the filter.
But the signal seems strong, though (158 vs. 105 galaxies in each direction).
Basically, I'd wait a bit for someone to try to replicate with more data and more conventional measurements.
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#226I wonder if it’s already April’s Fools Day in some parts of the world. The hands of a clock move clockwise if seen from the front, but counterclockwise if seen from the back.
The article states that the problem is that they looked at random galaxies, 1/3 were moving one way and 2/3 the other.
If the distribution was truly random, and the universe is isotropic, we should see roughly 50/50.
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#227Earlier quoted context omitted.
There doesn’t need to be a reason, just random chance from gasses shifting around is sufficient.
I think you are misunderstanding the point being made: The _only_ random chance that is part of current models is "quantum uncertainty at big bang time" and we can give upper bounds for the variations that can be explained from that. So what's really being said here is "We found a significantly larger discrepancy between Milkyway-corotating galaxies and Milkyway-counterrotating galaxies than can be explained by ~init…
That doesn’t make sense, they can’t be assumed to have behaved like ideal gasses, thus turbulence alone can cause significant uncertainties.
Let alone all other possibilities combined.
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#228Earlier quoted context omitted.
Dumber question: would a galaxy that appears to spin clockwise appear to spin counter-clockwise when viewed from the other side? Does this imply that the real question is why galaxies' relative orientations seem to favor more spinning in one direction than the other?
This is exactly the dumb question I came here to ask. So now I wait with you for a less dumb person to reply. My clock certainly seems to tick in the opposite direction when I look at it from behind.
Answering to your and original question above: there are no poles (or axes of rotation) in the Universe. On large scales (think distances to include thousands and millions of galaxies each with billions of stars with even more planets) the Universe is uniform - isotropic and homogeneous [1]. It is expanding with acceleration in all direction in each and every point of its space, so there is no preferred direction thus in average we should have 50% of clockwise and 50% of counter-clockwise galaxies since orientation of those should also be absolutely random in average, unless something when the Universe was being created or evolving affected that balance.
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#229> The same solo author (a computer scientist) has made many similar claims based on a variety of datasets. Often coming to completely contradictory conclusions. Some of these claims have been followed up by astronomers, who found errors in his analysis and poor statistical tests. His claims have been discussed in this sub before. Independent studied have found no significant evidence of anisotropy.
https://academic.oup.com/mnras/article/534/2/1553/7762193
https://ui.adsabs.harvard.edu/abs/2021ApJ...907..123I/abstra...
https://ui.adsabs.harvard.edu/abs/2017MNRAS.466.3928H/abstra...
>Take his claims about JWST as an example. In 2024 he wrote a paper about some early data, claiming to find more galaxies rotating with the Milky Way. He claimed based on a sample of just 34 galaxies that the signal was significant. Now he has looked at a wider dataset of the same area, which should allow him to verify his analysis. But it shows exactly the opposite, more anti. So he writes a paper saying this new result is definitely significant but doesn't reflect on the fact he has written two papers which contradict each other. He has failed to reproduce his own result. The take away is that his results are not as significant as he claims. He's also looking at a tiny area, and nearby galaxies can have correlated spins. He doesn't take this into account either. There are multiple JWST fields in different directions he could examine in different directions to test his claims, there are two JADES fields, but he only publishes one.
>I do wish the MNRAS editors would take measures to stop publishing low quality claims like this without more robust review. If you look at the text, it’s largely repeating results from his old papers. There’s very little discussion of the new results.
source: https://www.reddit.com/r/cosmology/comments/1ja9i53/the_dist...
Re: James Webb Space Telescope reveals that most galaxies rotate clockwise
#230Earlier quoted context omitted.
Space and time are related, and expanding rapidly since the Big Bang (though there was a time in the early universe when the expansion rate was faster). https://cds.cern.ch/images/CERN-HOMEWEB-PHO-2022-023-1 Observing the edge is effectively looking back in time, to see the conditions of the universe closer to the time of the Big Bang. New telescopes keep expanding that edge, and new particle colliders (such as those…
Wait, I get space expanding and accelerating. I never considered time expanding (and accelerating?). Is that even possible? What does that imply?
Finding a way to reverse the expansion of the universe would imply time travel being possible. It hasn't happened yet, but perhaps that's just a technological limitation. And if you ask my Mac, then Time Machine is very much possible - that's just the name of the backup system.
The question starts to become very philosophical if there is a backup system for this universe. Everything being saved, for eternity, in infinite time. It would require very advanced computational power and storage, but it would probably work in binary (but that's just the kind of thing a computer engineer would say).
Maybe, though, the observable universe is rotating clockwise around a centre that is in the unobservable universe, and time is just a measure of how many rotations have been made since the Big Bang.