I’m not a physics expert by no means, so bear with me.
From my understanding, galaxies seem to gravitate toward one another, more than our laws of physics can account for, or mysteriously to certain areas. Scientists have surmised these areas are filled with intangible matter, or at least intangible to our universe, or dimension. A question arises - Why does this undetectable matter affect detectable matter gravitationally, but not in other ways, a question for which there might be no explanation.
Could there be an alternative, physical explanation? Perhaps the universe is filled with gravity zones. Areas of space and time that attract visible matter toward them.
We expect the laws of physics to everywhere be the same, but large bodies (galaxies) might possess a disproportionately powerful attraction, or, is it small bodies (stars, planets) that possess a disproportionately weak attraction. Maybe gravity begins to multiply, rather than add, when a body reaches a certain mass.
Or, scientists may have underestimated galaxy mass. They might be far more dense than we believed. “black holes” (I don’t like that name, it’s missleading) might be to blame for this. hmmm, yet another explanation. Black holes might be responsible. The universe could be teeming with black holes everywhere. Some could have the mass of dozens or even hundreds of galaxies. Black holes that have taken eons to form. Slowly they have consumed dozens or hundreds of galaxies overtime. So why haven’t we been consumed by them? Why hasn’t the earth been consumed by the sun? Perhaps the big bang will occur, if it does occur, when all the black holes in our universe have fused together. They will send all matter back outward. Then, the process will begin all over. Before this happens, because black holes are so few and so massive, from gradually consuming their neighbours, the universe could be concentrated in just a few areas.
If dark matter does exist, one explanation for why we can’t see it, is it might be too small. It only has a collective, gravitational power, it has no power to affect us individually. There may be smaller universes within bigger universe, like Russian Dolls.
Since we cannot currently directly detect whatever’s causing this excess of gravity, we can only infer and assume what it is. My explanations could be just as valid and plausible as the scientists.
On a side not, i think we should rename black holes. I don’t think they are holes, tears in fabric of space time. They’re super massive objects.