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 36 points 6 days ago* (last edited 6 days 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 21 points 6 days 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.

[–] RedditWanderer@lemmy.world 5 points 6 days 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.

[–] mumblerfish@lemmy.world 3 points 5 days 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.

[–] anindefinitearticle@sh.itjust.works 1 points 4 days ago

From the formation of the CMB we know that the whole universe was a hot and dense plasma that cooled and became transparent.

Are you proposing that these galaxies existed before and external to the CMB plasma ball "big bang" that we came from?

As in, a bunch of matter appears inside of a pre-existing universe as a local big bang, whose galaxies spread out amongst preexisting galaxies from older big bang events?

Then you propose that matter which has been hoarded by black holes may be the source of the matter in subsequent big bangs, to achieve a steady state.

I like the idea you are proposing.

My biggest question is: why didn't our "bang" blow all of the older generation of galaxies away from it such that we would never see them? My understanding is that spacetime itself is what expands / inflates in λcdm. It does so faster than the speed of light such that there is material in our universe from which light will never reach us. It's very hard to see things outside of a universe that expands faster than the light we use to observe it. It's spacetime itself that's expanding, not just the objects moving apart.

But, MOND is MOdified Newtonian Dynamics, and currently doesn't work with Einstein/GR... at all! So, if MOND is right maybe we should expect a different mechanism than Einstein expansion.

Most likely we just don't understand what stars and nebula looked like or how they formed back before metals existed and so we don't know how bright these galaxies should be to begin with because we don't know how stars work without metal. The assumption in the paper is irresponsibly invalid, we can't just assume that stars back then followed the same patterns as stars do now. Stars form from nebulae because metals condense out and coalesem creating nucleation sites for mass accretion. Earlier generations of stars would need to rely on different formation mechanisms, and likely had a different size and brightness distribution. We won't understand these early stars and galaxies until we've been looking at them for at least a decade.

[–] cynar@lemmy.world 1 points 4 days ago

The big bang wasn't an explosion in space, but OF spacetime. Anything that might have existed before would have been fundamentally different, and completely destroyed in the event.