The James Webb Space Telescope is finding too many early galaxies • Hacker News Board

Re: The James Webb Space Telescope is finding too many early galaxies

#341

Post by [deleted] » Fri, Jan 13, 2023, 3:28 AM UTC

pmayrgundter wrote: post #168

reptation wrote: post #110

Earlier quoted context omitted.

It's worth pointing out that there is a minority of physicists who don't accept the Big Bang as proven beyond doubt. An alternative theory would be a 'steady-state' universe which, as you suggest, would be much older than the ~14 BYO age. If the medium of space itself dispersed light for instance, red shifts might be observed that explain the astronomical data.

Eric Lerner is one of them and he's advocating for the idea that the BB never happened and that we'd see plenty of old galaxies with JWST. He's since updated his thoughts and there was a bunch of controversy: https://news.ycombinator.com/item?id=32938153

[deleted]

Re: The James Webb Space Telescope is finding too many early galaxies

#342

Post by simonebrunozzi » Fri, Jan 13, 2023, 3:33 AM UTC

sebzim4500 wrote: post #98

college_physics wrote: post #59

I don't know if this instance qualifies as one, but I think its fair to say that cosmology is the one domain of "fundamental" physics where "discrepancies" or question marks keep piling up and not really resolving. It the pattern of previous science revolutions repeats, there could come a point where reinterpreting the large existing body of knowledge using a different paradigm would explain an number of "oddities" i…

I think this says less about cosmology and more about the incredibly effectiveness of the standard model in the regime we can test directly on earth. If we compare ΛCDM to most other scientific theories it doesn't look so bad in terms of discrepancies. Certainly there are many unexplained effects in solid state physics, there isn't even an accepted explanation for why rubbing a balloon on your head makes it stick to…

> ΛCDM

Lambda-CDM Model [0], for the ones like me who haven't heard it before.

[0]: https://en.wikipedia.org/wiki/Lambda-CDM_model

Re: The James Webb Space Telescope is finding too many early galaxies

#343

Post by deepsun » Fri, Jan 13, 2023, 3:37 AM UTC

dark-star wrote: post #208

TheOtherHobbes wrote: post #151

I'm going to be very amused if the Steady State Model - an unpopular relic from the 1940s - turns out to be correct. https://en.wikipedia.org/wiki/Steady-state_model

My favorite theory is that the universe is finite, some sort of (hyper)sphere or -torus. If we could just look far enough out there we would see our own galaxy What would be even cooler is if it was warped like a moebius strip in a higher dimension, so that when we look out there, everything is mirrored from "our" reality :-D

That assumes that we can somehow see through time, which leads to a whole bunch of inconsistencies (aka time travel paradoxes). There's no way to look through large distances without looking back in time, unfortunately.

Re: The James Webb Space Telescope is finding too many early galaxies

#344

Post by thereisnospork » Fri, Jan 13, 2023, 3:43 AM UTC

michaelhoney wrote: post #227

abtinf wrote: post #211

Earlier quoted context omitted.

If “it all keeps changing”, which thwarts their attempts to “model an insanely complex system”, then wouldn’t that mean any claim about “global warming” is actually a claim to possessing a priori knowledge?

No. That the planet is warming is incontrovertible. What this might mean for highly interdependent, chaotic systems is harder to predict. Will the Greenland ice sheet melt? Looks like yes. Will that affect the Gulf Stream? Probably. Will that make Spain colder? again, probably, but the error bars are bigger, and so on.

It just sounds like global warming is giving them good test data. A comprehensively accurate model should be able to take e.g. a Greenland ice sheet melting in stride.

Re: The James Webb Space Telescope is finding too many early galaxies

#345

Post by deadbeeves » Fri, Jan 13, 2023, 3:47 AM UTC

lp4vn wrote: post #185

Tuna-Fish wrote: post #22

Earlier quoted context omitted.

We can't see down to 0 seconds, because very soon after the big bang, the universe was filled with dense, extremely hot, opaque plasma. The closest we can get is the "recombination epoch" [0], which is roughly 370 000 years after the big bang, when, because of universal expansion, the plasma got cold enough for neutral hydrogen to start forming, at which point the universe became transparent. As protons gain electron…

What I'm going to ask you is completely dumb, but keep in mind I don't know much of physics. If my understanding is correct, when mass gets dense enough inside, a star you have a black hole, that would be like a hole in the fabric of space time. Ok, we have black holes in the contemporary universe. So how was the primordial universe a ball of dense, extremely hot, opaque plasma without becoming a huge black hole?

Because the primordial universe was in a state of extremely fast expansion, while black holes today exist in space-time that is almost exactly flat. In fact, if the universe really started from a singularity, the expansion was infinitely fast for an instant.

Re: The James Webb Space Telescope is finding too many early galaxies

#346

Post by JacobThreeThree » Fri, Jan 13, 2023, 3:51 AM UTC

moloch-hai wrote: post #294

jackmott42 wrote: post #105

Earlier quoted context omitted.

I don't think it is fair to characterize cosmology as not making progress no. Stuff is far away and occluded and hard to measure and see. Each improvement in observation causes a need to refine previous ideas, as expected. There are of course the two big mysteries that have lingered for a long time: Dark Matter and Dark Energy, but other areas of physics have lingering mysteries as well.

Nobody says cosmology is not making progress. People dunk on cosmology because cosmologists have consistently, over decades, insisted, in public, that they knew more than they did, and are continually obliged to abandon what they insisted they knew. If they were more forthright about how much they don't know, they would get less criticism. They have much to learn from the biologists, who know they know practically no…

>cosmologists have consistently, over decades, insisted, in public, that they knew more than they did

Exactly, and each time the theories are proven wrong, it's explained as a never-ending series of "oddities", yet the theories are never altered in any meaningful way other than ad-hoc additions to explain each "oddity".

At some point there needs to be a reckoning that, for instance, the current theories of star formation are essentially completely wrong.

Re: The James Webb Space Telescope is finding too many early galaxies

#347

Post by NineStarPoint » Fri, Jan 13, 2023, 3:52 AM UTC

godshatter wrote: post #229

chrisweekly wrote: post #112

Earlier quoted context omitted.

wait, no, a big bang doesn't happen IN spacetime, it IS spacetime per se. that's part of what makes it so confusing.

What is spacetime expanding into?

Unless we figure out a way to take measurements of areas outside of space-time to compare against (which seems quite impossible), it’s probably a question humanity will never answer.

It might be a question with no meaning: The universe interacts with nothing else. It spawned out of nothing, and its expansion is only meaningful if you’re inside the universe to see it happening.

It could be a question with a lot of meaning: perhaps the universe exists on top of some higher dimensional substrate that is conducive to big-bang style expanding universes. Maybe the reason the universe expands is only possible to answer by having access to the information of what it is expanding into.

It could be question impossible to wrap our heads around: Maybe the area outside the universe runs on metaphor, and our universe expands in a sense that would make more sense to a writer than a physicist.

Basically, endless sci-fi can be written about that question. But given we are (probably) restricted to staying within our universe’s laws of physics, it’s quite likely we’ll never really know.

Re: The James Webb Space Telescope is finding too many early galaxies

#348

Post by deepsun » Fri, Jan 13, 2023, 3:52 AM UTC

eigenket wrote: post #217

drdeca wrote: post #201

Earlier quoted context omitted.

What’s wrong with it being (topologically) a 3-sphere ? That seems plenty symmetric to me.

Theres nothing massively wrong with it, it's a perfectly plausible model. The one thing that isn't particularly nice is that spheres have intrinsic curvature, essentially if you draw two parallel lines on a sphere they will eventually touch. We can go and look at astronomical data and see if the universe has any intrinsic curvature that we can see. People did this and it turns out that from all the astronomical data…

To be pedantic, there is curvatures, see lensing effect of large masses. It's not global, though.

Re: The James Webb Space Telescope is finding too many early galaxies

#349

Post by ckw » Fri, Jan 13, 2023, 3:57 AM UTC

brap wrote: post #221

TheOtherHobbes wrote: post #151

I'm going to be very amused if the Steady State Model - an unpopular relic from the 1940s - turns out to be correct. https://en.wikipedia.org/wiki/Steady-state_model

Since everyone is mentioning their favorite whacky theories, mine is the one that says within every particle is a whole universe, made up of particles with their own universes and so on, and what we call our universe is really just a particle in an even bigger universe. And what if all of those universes were actually the same universe, like some infinite recursion? Is there a name for this?

Animal House: https://youtu.be/JUOGxePBs50

Pascal:

  […] But to show him another prodigy equally astonishing, let him examine the most delicate things he knows. Let a mite be given him, with its minute body and parts incomparably more minute, limbs with their joints, veins in the limbs, blood in the veins, humours in the blood, drops in the humours, vapours in the drops. Dividing these last things again, let him exhaust his powers of conception, and let the last object at which he can arrive be now that of our discourse. Perhaps he will think that here is the smallest point in nature. I will let him see therein a new abyss. I will paint for him not only the visible universe, but all that he can conceive of nature's immensity in the womb of this abridged atom. Let him see therein an infinity of universes, each of which has its firmament, its planets, its earth, in the same proportion as in the visible world; in each earth animals, and in the last mites, in which he will find again all that the first had, finding still in these others the same thing without end and without cessation. Let him lose himself in wonders as amazing in their littleness as the others in their vastness. For who will not be astounded at the fact that our body, which a little while ago was imperceptible in the universe, itself imperceptible in the bosom of the whole, is now a colossus, a world, or rather a whole, in respect of the nothingness which we cannot reach? He who regards himself in this light will be afraid of himself, and observing himself sustained in the body given him by nature between those two abysses of the Infinite and Nothing, will tremble at the sight of these marvels; and I think that, as his curiosity changes into admiration, he will be more disposed to contemplate them in silence than to examine them with presumption.

  For in fact what is man in nature? A Nothing in comparison with the Infinite, an All in comparison with the Nothing, a mean between nothing and everything. Since he is infinitely removed from comprehending the extremes, the end of things and their beginning are hopelessly hidden from him in an impenetrable secret, he is equally incapable of seeing the Nothing from which he was made, and the Infinite in which he is swallowed up.

Re: The James Webb Space Telescope is finding too many early galaxies

#350

Post by deepsun » Fri, Jan 13, 2023, 3:58 AM UTC

bbreier wrote: post #314

whaaswijk wrote: post #308

Earlier quoted context omitted.

While I agree that simulation theory pushes the question up a level, that is not the case for the God of classical theism.

Ok, I'm curious. How does the explanation for everything's existence being "God did it" not simply push the question up a level to wondering how to explain God's existence?

I just noticed that if you replace "God" with "Big Bang", it's pretty much the same question.

The answer to Big Bang is that before it, there was no time itself, so there's no notion of "before" (or if you wish, it's an error in the question itself that assumes there was "before").