Astronomy

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.

Thanks, that clued me in to the existence of superclusters, a term I've never heard before, and then I somehow wound up here in search of my answer of if the superclusters are orbiting each other. That's a good read, for anybody interested, but here's the summary:

One object orbiting another is an illusion. Instead, all objects orbit their common center of mass, called the barycenter. It looks like we orbit the sun because our common center of gravity is beneath the sun’s surface.

When it comes to galaxies, we can say that each one in a cluster, such as our local group, is gravitationally bound and orbiting a common barycenter. That means the Milky Way is orbiting a point in space roughly midway between here and the Andromeda galaxy.

At the scale of superclusters, however, the mass is too spread out and homogenous for centers of gravity to form. With no common center of gravity, clusters of galaxies have nothing to orbit and so don’t.

Instead, they are steadily pushed apart by the expansion of space.

I believe Andromeda is part of Laniakea? Would make sense but I could be wrong

Empty bits, basically. They're regions where there's significantly less stuff than average. Because there's less stuff there, surrounding stuff gets pulled away from that region in every other direction by gravity, so it looks like the empty region is pushing stuff away from it. It's actually just failing to pull things towards it as hard as everywhere else is, but that's why they're called "repellers"

It seems like the issue has been confused a lot by a couple of things. First is a theory that if antimatter and matter gravitationally repulse each other it could explain dark energy, so voids like this might be full of antimatter pushing everything else away. Consensus has, however, generally settled on gravity attracting matter and antimatter to each other just as it would matter to matter. CERN is able to produce antimatter and experiments seem to have confirmed the consensus.

Second, the scientist that led the project that identified the dipole repeller seems to be very insistent on referring to it as actually pushing things, rather than an apparent pushing that arises from pulling less than everything else. Now, to be clear, I'm no expert. I'm a qualified mechanical engineer so I have a decent grasp of physics, but I'm still a complete amateur and outsider in the world of astrophysics. I also don't know anything about the scientist in question. I say this so that you can take it in to account when I say that it really, really looks to me like the guy is doing it deliberately to grab headlines because "big patch of space emptier than expected" isn't easily understood to be as much of a discovery as it actually is

But basically, yellow bits on the map = big patches with less stuff in them than usual