Ring of galaxies challenges thinking on cosmos
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Re: Ring of galaxies challenges thinking on cosmos
#2For those interested in learning more about the Cosmological Principle
PSB Spacetime- Where Is The Center of The Universe?
https://www.youtube.com/watch?v=BOLHtIWLkHg
Giant Arc 3.3 Billion Light Years Long That Shouldn't Really Exist:
https://www.youtube.com/watch?v=Wj1ULGmPe6s
The Case Against the Cosmological Principle (and/or FLRW) - Jenny Wagner:
https://www.youtube.com/watch?v=nASUsWQyemc
SciShow- What If the Universe Isn't Uniform?
Re: Ring of galaxies challenges thinking on cosmos
#3And Is the Observable Universe Consistent with the Cosmological Principle?
- Classical and Quantum Gravity 40(9) (April 2023)
Re: Ring of galaxies challenges thinking on cosmos
#4I don't understand. Since the entire universe might be huge compared to the observable universe, is this structure really that unlikely?
Re: Ring of galaxies challenges thinking on cosmos
#5The bbc has a better article in their science section at https://www.bbc.co.uk/future/article/20230302-the-giant-arcs... dated March 2023. Today’s article is triggered by a presentation of results but contains less information.
Re: Ring of galaxies challenges thinking on cosmos
#6I don't understand. Since the entire universe might be huge compared to the observable universe, is this structure really that unlikely?
In another article at https://www.bbc.co.uk/future/article/20230302-the-giant-arcs...
“According to Lopez's article, it is extremely unlikely (a probability of just 0.0003 per cent) that such a large structurei could have arisen by chance.”
The particles to make up the structure had to come from somewhere, and the best models of gravitational movement would say that such a structure would have taken too long to form. The arc is 1/15th the radius of the known universe.
Such a structure isn’t ruled out by the cosmological constant. It’s highly unlikely.
The distinction here is “unlikely to form anywhere” versus “unlikely for us to be situated in a position we could see such an unusual formation”.
Re: Ring of galaxies challenges thinking on cosmos
#7How do we measure the distance to those galaxies to be sure that it’s really a ring, rather than something that looks like a ring from our perspective? I know that supernovas provide one technique for distance measurement, but it feels unlikely that we’ve done that for every galaxy in this structure?
Re: Ring of galaxies challenges thinking on cosmos
#8How do we measure the distance to those galaxies to be sure that it’s really a ring, rather than something that looks like a ring from our perspective? I know that supernovas provide one technique for distance measurement, but it feels unlikely that we’ve done that for every galaxy in this structure?
All the illustrations we see about galaxies are post-processed interpretations, they are not exactly photos per se. In this case, I think astronomers may be using the data sent by the Voyagers[1] as a ground truth for trying to interpolate the scanned one from distant galaxies.
It is not my field, but perhaps another probe should have been launched on a different axis as you indirectly suggest, although it should have been done at the same time. I'd bet someone at NASA thought on it and the budget stopped it.
[1] https://www.newscientist.com/article/dn21233-voyager-space-p...
Re: Ring of galaxies challenges thinking on cosmos
#9The Xeelee have begun construction of the Ring.
Re: Ring of galaxies challenges thinking on cosmos
#10How do we measure the distance to those galaxies to be sure that it’s really a ring, rather than something that looks like a ring from our perspective? I know that supernovas provide one technique for distance measurement, but it feels unlikely that we’ve done that for every galaxy in this structure?
All the illustrations we see about galaxies are post-processed interpretations, they are not exactly photos per se. In this case, I think astronomers may be using the data sent by the Voyagers[1] as a ground truth for trying to interpolate the scanned one from distant galaxies. It is not my field, but perhaps another probe should have been launched on a different axis as you indirectly suggest, although it should hav…
Other galaxies are too far away for us to have any way to view them from a significantly different angle -- the solar system is tiny compared to the size of galaxies and the distance between them.
How does the voyager article relate to this study? It looks like voyager just got far enough away from the sun to detect something in our galaxy that was hard to see from earth due to being drowned out by the sun, and the rest is hidden by a paywall.