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The James Webb Space Telescope is finding too many early galaxies

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

#351

Post by dumpsterdiver »

emptybits wrote: post #272
vl wrote: post #198

Earlier quoted context omitted.

>Certainly there are many unexplained effects in solid state physics Wait for it… Why ice is slippery? Usual explanation is completely incorrect. Actual semi-conclusive research just recently happened.

I had to look that up. Here's research[1][2] from 2019 about "why ice is so slippery", including some of the apparent surprises. I dunno. I'm not a physicist so some of the surprises seem like very minor things to me. Spoiler: According to this research, ice is slippery because of a thin layer of water. (As we expected, no?) But the water layer is 1) thinner than expected, 2) more viscous than expected, and 3) contai…

> Only for an unusual definition of "completely" IMO.

Agreed. While the "usual explanation" may lack the details that actual testing provided, deduction and logic in this case were pretty much harmonious with the findings. The water layer being thinner or more viscous than expected doesn't invalidate the basic assumption, and that's where all science starts, right? Some basic, yet to be disproved* assumption.

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

#352

Post by [deleted] »

Jeff_Brown wrote: post #197
KMag wrote: post #111

Earlier quoted context omitted.

Due to accelerating cosmic inflation, some galaxies are receding from us at faster than the speed of light, so their light will never reach us. The majority of galaxies (everything outside of our local cluster, IIRC) will eventually be receding faster than the speed of light and be beyond our vision forever. Yes, this means most galaxies will appear to actually pass through/into the cosmic background, from our point…

I thought the logic of inflation had no limit, and eventually, everywhere, even atoms themselves would come apart.

[deleted]

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

#353

Post by brotchie »

azalemeth wrote: post #228
sebzim4500 wrote: post #98

Earlier quoted context omitted.

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…

My favourite example of the intractabilities of some theories is that magnetohydronamics apparently can't predict the formation of streamer jets when you put your finger on a kid's plasma ball – i.e. the main point of the toy is beyond the most advanced theory that lies behind NIF, JET, ITER, etc...

Intractable in the analytic sense, or intractable numerically… or both?

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

#354

Post by deadbeeves »

Jeff_Brown wrote: post #197
KMag wrote: post #111

Earlier quoted context omitted.

Due to accelerating cosmic inflation, some galaxies are receding from us at faster than the speed of light, so their light will never reach us. The majority of galaxies (everything outside of our local cluster, IIRC) will eventually be receding faster than the speed of light and be beyond our vision forever. Yes, this means most galaxies will appear to actually pass through/into the cosmic background, from our point…

I thought the logic of inflation had no limit, and eventually, everywhere, even atoms themselves would come apart.

You're describing the Big Rip. It's now thought that the acceleration of expansion is not high enough for that to happen. Gravity is strong enough that the particles inside galaxy groups will stay causally connected indefinitely. Long enough into the future, whole groups will become disconnected from the rest of the universe, though.

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

#355

Post by moloch-hai »

JacobThreeThree wrote: post #346
moloch-hai wrote: post #294

Earlier quoted context omitted.

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 forma…

Galaxy formation, anyway, or maybe galaxy supercluster formation.

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

#356

Post by deepsun »

dougmwne wrote: post #174
seanw444 wrote: post #29

Earlier quoted context omitted.

So if we can see CMB in all directions, why do we really even say "the observable universe" as though there could be more matter and more galaxies beyond what we can see? If the maximum of what we can see is implied to be before all galaxies, then shouldn't it be implied that all galaxies that exist can be seen?

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…

To "what exists today, beyond 13.7 billion light years", I'd rather say that "it doesn't exist yet". Because, otherwise, it assumes there's some "global universe time" like UTC or something. But all there is is our light cone.

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

#357

Post by DiggyJohnson »

eru wrote: post #329
moloch-hai wrote: post #281

Earlier quoted context omitted.

It is easy for children to come up with questions for biologists that none can answer, and that none has even tried to answer. Biologists are almost unique among scientists in being happy to say how little they still know about their subject. Up until last year nobody had thought to see whether anything eats viruses! Turns out some do.

> Biologists are almost unique among scientists in being happy to say how little they still know [...] Citation needed. > Up until last year nobody had thought to see whether anything eats viruses! Turns out some do. Nah, lots of things eat viruses. It's nothing unusual at all. You eat viruses, I eat viruses. They are everywhere, after all. The novel finding was a critter that lives / can live solely on viruses.

> Citation needed

How could you possible find a citation for that? It’s not even pretending to be a scientific or totally objective claim. Asking for a citation for this type of statement is no way to have a discussion. Do you not see why?

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

#358

Post by ordu »

suetoniusp91 wrote: post #192
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…

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

It is a v0.93 of simulation, which was run a long time ago. Software was patched since and now simulation is much smoother.

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

#359

Post by cwalv »

maegul wrote: post #275
Buttons840 wrote: post #264

Earlier quoted context omitted.

At this point in the thread, I'm wondering if we do a disservice to physics students by making it appear we have it all figured out.

So much this! There’s surely a huge argument that all of scientific education is a massive disservice. The point should be to learn and appreciate the method or process of scientific investigation of uncertain and mysterious or hard to understand phenomena. Instead we get dogma as a proxy of measuring intelligence with little regard for what the fundamental tools are of being a scientist. I’ve gone all the way throug…

> There’s surely a huge argument that all of scientific education is a massive disservice.

> If the general public is to benefit from education and pass that benefit into their society (that’s the point right), it needs to be more than soon to be forgotten and often useless fallacies.

I realize this is hyperbole, but still I think it's obvious that there is more than soon to be forgotten and often useless fallacies.

I do generally agree though that current models/paradigms are usually presented more as "the final word" vs "a useful mental model".

Esp. when paradigms are challenged by, or conflict with untestable traditional explanations, ppl tend to get irritated and overstate the confidence of their own understanding

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

#360

Post by deadbeeves »

10g1k wrote: post #316

A lot of academic/scientific belief is based on ignorance. Hear me out. The entire academic/medical establishment believed the appendix was "just a vestigial organ" which served no purpose. It was taught in every university, in every textbook. Every medical professional knew it was a fact. Why? Because they had not identified a purpose. In their ignorance, they adopted the position "I don't know what it does, therefo…

Vestigiality is not about having no function, but about losing the original function. Vestigial organs are also often in an atrophied state when compared to analogs in other species. The appendix is indeed vestigial, and while not entirely without function, it is almost entirely without one, to the point that you can not have it and not even realize it.

>When the most powerful telescope could see N lightyears, people believed the universe was N years old. [...]

What are you talking about? Before the 20th century it was believed that the universe was eternal. After then, advances in determining the age came primarily from theoretical models, not improvements in equipment.

>Yet astronomers and cosmologists refuse to learn the lesson, and keep repeating the same mistake.

You seem to be under the misapprehension that the goal of science is to not make incorrect statements. It's not. It's to incrementally (by necessity) learn about reality. There's nothing with the statement "by our best current measurements, the universe is about 13 billions years old" even if tomorrow new findings point to it being twice as old. To demand otherwise would mean that no conclusions can ever be drawn, because necessarily all scientific conclusions are tentative. It is true at all times that tomorrow's evidence may overturn today's conclusions.

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