ELi5 the implications from this discovery by the Jwlt?


** JWST**

“These objects are way more massive​ than anyone expected,” said study coauthor Joel Leja, assistant professor of astronomy and astrophysics at Penn State University, in a statement. “We expected only to find tiny, young, baby galaxies at this point in time, but we’ve discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe.”

In: 2

Galaxy evolution models are incomplete. Scientists will incorporate the new data and come up with more accurate models.

* Since, due to light traveling at a finite speed, looking super far away helps us look backwards in time, we can see what the universe looked like at super early times by looking super far away, which we couldn’t really do well until JWST

* The way we currently think galaxies form has them taking a certain time to reach a certain size. The universe had a point where it was an almost perfectly uniform cloud of gas, but those slight imperfections determined where the first galaxies formed. Those imperfections needed some time though to grow

* We found galaxies that were way more massive than these models said we’re possible when the universe was this young since they shouldn’t have had time to grow yet

* We already knew our galaxy forming models aren’t very good (it’s a huge research area right now) so this wasn’t world changing on its own, but it does mean we need to revisit the few things we thought we knew about how galaxies formed.

* We know dark matter is super important for galaxy formation, but don’t really know much about it (also a huge research area) so that’s probably where the issue is