• Chetzemoka@kbin.social
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    1 year ago

    So, maybe this picture will help a little? It has the gravity flow lines on it.

    The blue is the Laniakea Supercluster. It’s a bunch of separate galaxies that are gravitationally connected to one another (moving through the universe in a similar way). Everything in that cluster is flowing toward a point in the center called “The Great Attractor.”

    Interestingly, we don’t actually know what The Great Attractor is yet, because it’s on the other side of the center of the Milky Way from us, so all the stuff in the way is really hard to see through. (We call this the Milky Way’s “zone of avoidance”)

    It’s possible that The Great Attractor point is actually an illusion caused by the gravitational effect of the Shapley Supercluster pulling us in its general direction, but we’re not entirely sure yet.

    The two yellow patches are areas that we’re flowing away from in a way that makes it appear that something there is pushing us away. Personally I side with the idea that this is also just an illusion and there’s not really anything there pushing, just that our being pulled away from that area by The Great Attractor and the Shapley Supercluster makes it look that way.

    • yarn@sopuli.xyz
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      1 year ago

      Your first sentence sounds like you meant to link a picture, but it looks like the link might be missing.

      But thanks for the clarification. One thing is I linked to this guy elsewhere in the comments, who explained that the force of gravity is too weak at the supercluster scale for clusters of galaxies to be attracted to each other. But you mentioned that the clusters within the Laniakea Supercluster are attracted to The Great Attractor, and then you further said that the entire Shapley Supercluster is pulling on the entire Laniakea Supercluster. So I’m just wondering, was that guy I linked wrong? It was a random google search on a topic I know nothing about, so I wouldn’t be suprised if it’s wrong, but maybe I’m misunderstanding what he was trying to say too.

      • Chetzemoka@kbin.social
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        1 year ago

        Oh that’s weird! I can see the picture. I wonder what instance you’re on? I’m on kbin.social. We should let the admins know that linked pictures aren’t coming through.

        And the answer to your question is: Not all gravitational influence is orbiting! “Attracted by” doesn’t necessarily imply orbiting, and yes your link is absolutely correct that these superclusters are not and never will be orbiting one another. But they are affected gravitationally.

        It gets a little weird to think of at this point, but think about that object that passed us a while back called Oumuamua. It’s believe to be from a completely different solar system, and yet managed to leave the orbit of that solar system and fly past us. So our sun definitely affected it gravitationally, but not strongly enough to pull it into orbit and it’s flying away from our solar system now.

        To understand these things, you have to change the way you think about what gravity is. You can think of gravity less as a “force” and more as the effect that massive objects have on space itself, warping and bending the shape of space. This creates sort of 3-D “hills” and “valleys” where gravity is weaker or stronger. And objects traveling through space *including photons of light" flow along those ripples, bending in the general direction of an area of a high concentration of mass and away from areas of low concentration of mass.

        On the greatest cosmic scales like these superclusters, we see a general flow of massive objects along a similar trajectory, both caused by and causing these mind-bending super structures. Everything is influencing everything else because it’s bending space itself.

        Here’s the source of the picture I posted, they describe these structures as gravitational water slides, which I think is adorable lol: https://skyandtelescope.org/astronomy-news/cosmic-void-pushes-milky-way-3001201723/

        https://en.m.wikipedia.org/wiki/Great_Attractor

        https://youtu.be/XRr1kaXKBsU

        https://youtu.be/0w4OTD4L0GQ

        • yarn@sopuli.xyz
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          1 year ago

          I’m on a lemmy instance called sopuli.xyz. This is what your comment looks like there:

          https://sopuli.xyz/comment/929467

          If I go directly to kbin.social, then I can see your image:

          https://kbin.social/m/astronomy@mander.xyz/t/160781/Map-of-about-0-001-percent-of-the-observable-universe#entry-comment-630589

          I don’t know a thing about kbin, I’m still new to lemmy myself, but it looks like that picture is an attachment or something on kbin, as opposed to being directly embedded in the comment. When I expand and collapse the text of your comment on kbin, the image always remains at the bottom, as if it’s not part of the text. Maybe that’s some kbin attachment functionality that’s incompatible with lemmy? I’m not sure. Or maybe it’s some kbin trickery to always display embedded images even if the text is too long and triggers a text collapse.

          Thanks again for the info about superclusters, though! This is all very fascinating.