Is it at all possible that instead of being pushed away, we are instead getting pulled toward something huuuuuge via gravity? As if we are falling into something way greater than ourselves? I thought this was a wild idea but after I Googled it I found out that there is such a thing as a “Great Attractor”. Something 150 million light-years away is literally pulling all nearby galaxies towards it but no one knows exactly what it is.

So how do we know there aren’t any other Great Attractors, Greater Attractors, ad infinitum?

    • BradleyUffner@lemmy.world
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      1 year ago

      No. Local attractive forces, like gravity, especially those at the atomic level, overpower the expansion for tightly coupled systems. So the earth isn’t expanding, and neither are the people on it. I don’t recall exactly what scale it kicks in at, but there is a good chance it’s not even affecting the distance between planets in a system. Most likely it only plays a role in inter-planetary-systems and larger. Ie, stars get further apart from each other.

      Edit. This explains it better https://www.astronomy.com/science/does-the-space-inside-an-atom-expand-with-the-universe/

      That says that the expansion really only applies to the space between galaxies. In anything smaller than that, gravity still overpowers the expensive forces. Making it far weaker than I initially thought.

      • qjkxbmwvz@lemmy.sdf.org
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        1 year ago

        It’s at a much, much larger scale** than that — our local group is collapsing in on itself, and it’s ~10M lightyears in diameter.

        ** talking about length scales only makes sense in reference to the specifics — two bananas separated by 10M lightyears, with no other matter nearby, would (I’m guessing) be expanded away, but a cluster of galaxies will not.

      • Zippy@lemmy.world
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        1 year ago

        Wouldn’t it cause some sort of force locally at the atomic level all the same even for tightly coupled systems? They shouldn’t feel the expansion as it is not a force from my understanding but just growth of space itself. But for example wouldn’t the orbit around an atom be off just so slightly that it would need to expend some level of energy to correct for lack of better word.

        Or do we think this does happen but the amount is so small that we can not measure it experimentally in any way.

    • spauldo@lemmy.ml
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      1 year ago

      The forces that hold your body together are many, many orders of magnitude stronger than the acceleration due to the expansion of space.