However, McGaugh and his colleagues argue that these predictions do not match JWST observations. Instead, the newly observed galaxies appear bright, large, and fully formed, even as scientists peer deeper into the universe’s past. This unexpected brightness directly challenges the conventional understanding of galaxy formation driven by dark matter.

Are you sure these aren't old galaxies? Like, how do we know that we aren't in a relatively small little bubble and there's an infinite universe out there where there isn't a single big bang, but instead small bangs that happen every now and then. Maybe if a black hole gets massive enough then its gravity "overflows" and causes it to vomit everything up; and all those bright, fully-formed galaxies are actually unrelated and proceeded the big bang.

[–] dustyData@lemmy.world 34 points 13 hours ago* (last edited 13 hours ago) (1 children)

We aren't looking at those old galaxies today. Due to the speed of light and the vast distance involved we are looking at the light from those galaxies when they were very young and early in the life of the universe (that's why we are looking there in the first place). That light is just now reaching us. We have theorized about white holes but never seen one. By looking at closer objects we already know what an old galaxy looks like. And nothing can by definition exist before the big bang. Because before the big bang there wasn't any space for things to exist in. Nothing precedes it.

[–] flueterflam@lemmy.world 19 points 12 hours ago (2 children)

The last three sentences are not quite accurate. It's not necessarily that nothing existed before the the big bang. It's a singularity event where mathematically we can simply not know what existed at/beforehand that moment. It is somewhat comparable with the event horizon of a black hole.

There is something happening/existing, otherwise a black hole would not be able to occupy space or affect light. We simply do not have the ability currently to understand what that is.

By definition, that is not nothing. It is a that we cannot know/understand it, at that moment. Notably, a lack of evidence is not evidence of nothing.

[–] mumblerfish@lemmy.world 2 points 7 hours ago

Not the event horizon of a black hole, but the singularity at the center. The event horizon is only a singularity in certain coordinate systems, but you can select coordinates that are smooth there. The black hole singularity is more comparable to big bang, in the sense that it is an indication of missing physics.

[–] RedditWanderer@lemmy.world 4 points 11 hours ago

He means the matter we know as galaxies today.

Our current theory implies that our space we know and love (bound by our time, spacetime) expanded at that moment. We know we shouldn't be seeing older galaxies that look younger than others we know to be young. That's what's implied by these findings at least - they could still be explained by other things we have yet to discover, because we haven't finished processing this data.

The title is just for the clicks.