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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

#441

Post by saberdancer »

pseudobry wrote: post #382
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…

> the uniform ultimate backdrop we have when looking in any direction Is the CMB exactly uniform in every direction? Or is this early light slightly more redshifted when we look up versus when we look down or left or right? Does the oldest light we see in any given direction vary slightly in color? I'm imagining the universe expanding as a sphere from a central point, but we're located off-center. Wouldn't the early…

Better to think of expansion as being a 2D dot on a balloon.

As balloon expands, in all directions there is same rate of expansion. You are not inside the balloon close to one side to observe the difference.

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

#442

Post by azalemeth »

brotchie wrote: post #353
azalemeth wrote: post #228

Earlier quoted context omitted.

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?

Both!

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

#443

Post by kzrdude »

pseudobry wrote: post #382
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…

> the uniform ultimate backdrop we have when looking in any direction Is the CMB exactly uniform in every direction? Or is this early light slightly more redshifted when we look up versus when we look down or left or right? Does the oldest light we see in any given direction vary slightly in color? I'm imagining the universe expanding as a sphere from a central point, but we're located off-center. Wouldn't the early…

The CMB is famously not exactly uniform https://www.esa.int/ESA_Multimedia/Images/2013/03/Planck_CMB

I have not read that any particular directions are evident in the sense you suggest though.

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

#444

Post by eru »

whatshisface wrote: post #407
eru wrote: post #386

Earlier quoted context omitted.

To be more precise, viruses are just made up of proteins and DNA / RNA. Your normal digestion that can handle proteins and DNA/RNA from animals, plants etc doesn't have any more problem breaking down virus proteins into amino acids and absorbing them.

I think the OP was talking about the bacteria that derive non-negligible sustenance from viruses. > Moreover, our foraging trials demonstrated robust growth in the Halteria population with only chloroviruses as food (rint = 0.66 ± 0.26 [SD], black lines, Fig. 1A), with minimal to no growth in the controls (with chloroviruses filtered out; rint = 0.22 ± 0.12 [SD], blue lines, Fig. 1C). The abundance of the larger Para…

Yes, I know. That's why I wrote

>> 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.

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

#445

Post by ankit219 »

kettleballroll wrote: post #424
ankit219 wrote: post #414

Earlier quoted context omitted.

I have kind of done that for last few months. Chat GPT helped immensely with that. I recently even asked if it's worth it to go back to academia. Still exploring that. A few things that I recently understood or read about. - Fermi Paradox - with help of chatgpt https://imgur.com/a/LuVV6iK - How the age of universe was calculated. - Redshift - How age of solar system was calculated. I previously thought just like the…

Interesting approach. Aren't you worried that chatgpt is feeding you bullshit without you noticing? I'd imagine chatgpt read as much science fiction content as science one, so there's no way to know if it tells the truth or hallucinations. How do you deal with that?

It's a good starting point. It may get some things wrong, but that's where my ability to research and truth seeking lies. I usually google more anyway because i want to go deeper than what chatgpt offers. I will eventually get to the truth. But the basic questions are well answered. I once asked it to explain the whole "Field has momentum" theory in a way a Feynman lecture would. It did it surprisingly well. I had some background so I kept asking more questions, and it was alright. Augments the curiosity, and make the topic seem simpler. Tools I use are: Google, science publications, and archive to see if there is text around it.

One small thing, the idea that chatgpt will feed bullshit is possible, so you have to be a bit skeptic and check the info, but it gets things right most of the times. Fun fact: I confused chatgpt about static electricity ie "Why does my hair get a static charge by rubbing a balloon?" It kept saying positive charge or negative charge, with transfer of electrons. Truth is, it's still poorly understood. [1] this paper highlights the conundrum.

For a beginner in college level physics, chatgpt is an excellent resource for understanding concepts.

[1]: https://www.researchgate.net/publication/360674587_Derivatio...

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

#446

Post by ankit219 »

smcnally wrote: post #438
ankit219 wrote: post #414

Earlier quoted context omitted.

I have kind of done that for last few months. Chat GPT helped immensely with that. I recently even asked if it's worth it to go back to academia. Still exploring that. A few things that I recently understood or read about. - Fermi Paradox - with help of chatgpt https://imgur.com/a/LuVV6iK - How the age of universe was calculated. - Redshift - How age of solar system was calculated. I previously thought just like the…

Anton Petrov regularly covers topics like these and encourages sharing with people interested in space and sciences. https://youtube.com/@whatdamath

Love it. Bookmarked. Thanks for sharing.

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

#447

Post by lnkl »

ankit219 wrote: post #414
xyzal wrote: post #410

Articles like these make me want to stop doing everything and isolate in the basement for several months to study physics. Then I realize I have a family to feed and elderly parents to take care for. Sigh, so many beautiful mysteries in the world, and only one life. edit: A friend told me germans have the word "Sehnsucht" to describe such a feeling. So I guess it might be somewhat universal.

I have kind of done that for last few months. Chat GPT helped immensely with that. I recently even asked if it's worth it to go back to academia. Still exploring that. A few things that I recently understood or read about. - Fermi Paradox - with help of chatgpt https://imgur.com/a/LuVV6iK - How the age of universe was calculated. - Redshift - How age of solar system was calculated. I previously thought just like the…

Seems like https://www.edx.org/xseries/astrophysics?index=product&query... would be of interest to you.

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

#448

Post by messe »

fartsucker69 wrote: post #429
jquery wrote: post #377

Earlier quoted context omitted.

It seems to me, as a layperson, if MOND was hypothesized first, it would be the dominant theory. It’s so elegant and simple with so much explanatory power. However, because it was hypothesized much later, the fact it matches past predictions is given no weight, despite its simplicity. I think this is a bit of a mistake. I believe that simplicity itself is evidence. Dark matter theory is starting to feel like the epic…

MOND mispredicts many, many past discoveries. This would have people scrambling for alternative explanations immediately. Dark matter is simply a better fit for what we see. Second, I don't know why MOND seems simpler and more elegant to you than literally something that doesn't modify the laws of physics at all but just increases the mass you use in computations.

I’m not a MOND proponent, but Cold Dark Matter also literally requires modifying the laws of physics, by positing new particles.

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

#449

Post by jstummbillig »

yipbub wrote: post #413
xyzal wrote: post #410

Articles like these make me want to stop doing everything and isolate in the basement for several months to study physics. Then I realize I have a family to feed and elderly parents to take care for. Sigh, so many beautiful mysteries in the world, and only one life. edit: A friend told me germans have the word "Sehnsucht" to describe such a feeling. So I guess it might be somewhat universal.

Same, but I imagine doing it in a country house with a table looking out into a lovely garden, and a mountain path nearby for long walks thinking about things.

It was beautiful and unexpected that this was not a "but"-one-up or "but"-and-here-is-why-you-are-wrong.

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

#450

Post by WithinReason »

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…

The relevant XKCDs:

https://xkcd.com/1867/

https://xkcd.com/2682/

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