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The James Webb Space Telescope is finding too many early galaxies

skyandtelescope.org

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

#231

Post by alisonatwork »

zelphirkalt wrote: post #205
dalbasal wrote: post #147

Earlier quoted context omitted.

So galaxies are falling off the edge of the universe never to be seen again?

I know it is considered increasingly unlikely, but: What a parallel to flat Earth ideas people had (...) hundreds of years ago, until they realized we are on a sphere. Maybe in a few hundred years people will laugh about our limited ideas of the universe as well.

This is wrong by an order of magnitude. It was already known thousands of years ago that the Earth is more-or-less spherical. The idea that people in recent history believed in a flat Earth is a myth.[0]

[0] https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth

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

#232

Post by yreg »

freedude wrote: post #129
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…

Fields of science should always be willing to change based upon empirical evidence. I think there are several other scientific areas where we know less than we ought. 1. The sub-atomic level 2. The cellular level 3. Ocean biology 4. Geology, particularly effects of earthquakes and volcanic activity 5. Weather patterns over time

What are the indicators we have marine biology wrong to the level of the other mentions?

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

#233

Post by delecti »

make3 wrote: post #34
pwatsonwailes wrote: post #18

Earlier quoted context omitted.

Without getting into lots of detail, this is basically correct. It's why we talk about the observable universe. There's lots of stuff we can't see because the light from it won't reach us.

how can that work if nothing is faster than light in the referential of the objects being compared? is it that space expands faster than light moves?

> is it that space expands faster than light moves?

Yes. Picture an ant walking on the surface of a balloon. You could conceivably blow up the balloon faster than the ant could walk across it. If you were blowing up an infinitely stretchy balloon with an ant at the far end, you could conceivably blow it up fast enough that the ant could never reach you.

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

#234

Post by rqtwteye »

throwawaymaths wrote: post #5

Worth noting: For a very long time MOND has been predicting earlier galaxies than LCDM.

As far as I know , MOND is not compatible with some observations. So dark matter and MOND have to be tweaked to agree with what we see.

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

#235

Post by yreg »

peatmoss wrote: post #220
suetoniusp91 wrote: post #192

Earlier quoted context omitted.

The simulation gets less cohesive the farther from earth you look.

I was just thinking about video games where vegetation, animals, and hills spring into existence when you get close enough. Far away, and they don't bother to render the little things. Depending what generation tech we're running on in the parent reality, JWST may be causing a noticeable jump in system load.

Whatever JWST can see should be trivial to convincingly mock compared to the complexity of simulation of the scenes here on Earth.

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

#236

Post by rqtwteye »

rcme wrote: post #32
varjag wrote: post #31

Earlier quoted context omitted.

But MOND itself is a "retrofit" to make it agree with the data, isn't it? It's in the name.

Every theory is a retrofit. A useful theory is also predictive.

MOND is not compatible with some observations. It and dark will probably be tweaked until both agree with observations. At that point they will be the same.

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

#237

Post by yreg »

purpleblue wrote: post #87
barbazoo wrote: post #78

Earlier quoted context omitted.

> 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" in a more economical way. Could we train a GPT3 like model with the entire corpus of astronomical research and try to answer some questions that way?

If you give GPT3 code with a bug in it, and ask it to find the bug, it can't really do that. I'm pretty sure giving it all the data and asking it why things aren't working the way it should, it wouldn't have actual knowledge. There's a depth to explaining things that GPT still can't do. It's still astonishing, and has completely changed my idea on what AI can do, like write plays with very incredible context (better…

It can definitely find and fix bugs. Of course it's not great at it and cannot be relied upon.

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

#238

Post by dpkirchner »

seszett wrote: post #81
seanw444 wrote: post #38

Earlier quoted context omitted.

Correct, as I understand it. No matter can travel at the speed of light, and no light can travel faster than the speed of light. But the rule doesn't extend to the rate of expansion of the "field" on which those things exist.

When I read this, it seems to me like this is more or less the same as saying that the speed of light is decreasing, but I am probably wrong?

Like if you calculated the speed not in meters per second but fraction-of-the-universe per second?

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

#239

Post by willbudd »

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?

Not a physicist at all either; but on a per particle basis, I know gravity is by far the weakest of the fundamental forces. However, unlike the others, it doesn't have spin/charge/polarity that results in their vectors repelling each other. As such, black holes form when the large scale weak gravitational forces combine into a greater force than the strong short scale repelling forces exerted by the others (and especially so when nuclear fusion is involved). In a hot primordial plasma, the particles are by definition extremely energetic; pushing each other in all directions with far more vigor than the extent to which gravity attracts them. Hence being a big bang rather than a big crunch, I suppose.

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

#240

Post by [deleted] »

tomp wrote: post #190
dougmwne wrote: post #174

Earlier quoted context omitted.

Here’s the important point I think you are missing. You are looking in TIME, not in space. When you look very far away, you are looking back to the beginning of time, back to a singularity where all matter and energy existed at a single point. In every “direction” you end up looking back to the same time and the same place, the beginning of everything. There’s nothing “beyond” that, it is the beginning. If you ask, w…

But if we're looking in the direction of a galaxy far far away (i.e. 14bn ly away) (which we don't know it's there, but let's assume it is, because likely some galaxies must be there), how come we see the CMB, which is 13.7bn years old, and not the galaxy itself, which is (by definition) less than 13.7bn years old?

[deleted]
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