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The James Webb Space Telescope is finding too many early galaxies
- mabbo 4y agoEthan Siegel isn't so certain: https://bigthink.com/starts-with-a-bang/most-distant-galaxies/ https://bigthink.com/starts-with-a-bang/most-distant-galaxie... The tl;dr is that we're finding quite a few red galaxies and red can mean distant (and therefore old) but you need to follow-up and do further direct measurements of each galaxy to be really certain that it's old and not red looking for some other reason. Some of these unexpectedly red galaxies have been followed up on, and some are indeed old, but it's not enough data points yet to be certain of anything. The fun part of science is that either way it's pretty exciting!
- namaria 4y agoYes! Beautiful pictures and scientists scratching their heads? This telescope is awesome!
- rossdavidh 4y agoThey do talk about that a bit in the article: "These candidates await spectroscopic confirmation: Their redshifts are only estimates for now. But so far, spectroscopic confirmations of other galaxies have confirmed the vast majority of preliminary distances. Even if only half of Yan’s selection turn out to be nearby galaxies masquerading as distant ones, the latter number would still be unexpectedly large."
- cwkoss 4y agoIs it possible that the 'edge' of universe reflects light? Have scientists been able to conclusively rule that out somehow? Does the universe even have an edge? What is our current understanding of what the boundaries of the universe might be like?
- eganist 4y ago> Is it possible that the 'edge' of universe reflects light? Have scientists been able to conclusively rule that out somehow? It's not an edge the way you think. It's the edge of what we can see based on the known age of the universe and how much light has reached us. I.e no real boundaries as best as we can tell. The best way you can look at this is that early galaxies are being found earlier than expected based on our model of how the universe formed. The further you look, functionally the further back in time you look (not just further away) This is an oversimplification and an astrophysics expert can give you something better.
- pwatsonwailes 4y agoWithout 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.
- oblio 4y agoI was thinking about something weird right now. We don't (can't?) even know if there weren't multiple Big Bangs, right? I.e we're just in a specific "universe" we can observe, but maybe several of these are just side by side, not necessarily parallel as in parallel realities.
- micromacrofoot 4y agoassuming light from a big bang travels in all directions, then another big bang's light could be heading in our direction and potentially observable — the reason we can't observe the entirety of our universe is that spacetime is expanding in a way where light at the beginning isn't traveling fast enough to outpace expansion
- chrisweekly 4y agowait, no, a big bang doesn't happen IN spacetime, it IS spacetime per se. that's part of what makes it so confusing.
- cevn 4y agoCan someone explain to me what would be behind the galaxies if we could see it, to the point of 0 seconds after the big bang? Black, white, is it even possible?
- ajross 4y agoThe very early universe can't be observed with visible light. It was filled with ionized hydrogen and thus opaque over long distances. The oldest light is from the era of "recombination", when things had cooled enough (c. 370k years after the big bang by consensus models) to permit light to travel. This is just the thermal glow of the universe, redshifted (way, way) down into the radio spectrum. And we can see it just fine; it's the cosmic background radiation and has been very well studied. It's the region between recombination and the currently-visible-to-telescopes galaxies that Webb is particularly well-suited to study.
- rjrodger 4y agoVisible light was scattering off densely packed electrons up to about 300k years after the Big Bang - so I guess - white.
- ben_w 4y agoWhite, redshifted so hard it's the blackest black we ever experience. (I want to add a H2G2 joke here, but I can't figure the right way to reference making God disappear in a puff of logic related to the Babelfish…)
- shadedtriangle 4y agoWe can see it and it’s called the Cosmic Microwave Background https://en.m.wikipedia.org/wiki/Cosmic_microwave_background https://en.m.wikipedia.org/wiki/Cosmic_microwave_background. It’s not t=0.0000001 though as the time before the cosmic microwave background the universe was opaque to photons, you wouldn’t be able to see anything.
- klodolph 4y agoCorrect me if I'm wrong. Cosmic microwave background is behind the galaxies, and we can see it. The universe is mostly transparent these days, so light can travel across the universe from a distant galaxy to our eyes or telescopes. Long ago, the universe was full of ions-free electrons and protons-and these are very effective at scattering light, so the universe was effectively opaque at that point. The universe became more transparent as the universe shifted towards hydrogen atoms instead of free electrons and protons. Whatever the universe happened to look like during that transition period, from opaque to transparent, is still what we see. It's the cosmic microwave background. Anything from before that time got absorbed.
- throwawaymaths 4y agoWorth noting: For a very long time MOND has been predicting earlier galaxies than LCDM.
- JetSetWilly 4y agoThis is not unusual. There's many predictions made by MOND ahead of the fact that are borne out by reality. But don't worry - dark matter will be "retrofitted" so that it fits the facts and everybody will suffer collective memory loss again. Edit: see for example table 1 on page 12 here: https://arxiv.org/pdf/2110.06936.pdf https://arxiv.org/pdf/2110.06936.pdf from a review of prior expectations by both MOND and dark matter vs how they turned out against reality for a large variety of astrophysical scenarios.
- varjag 4y agoBut MOND itself is a "retrofit" to make it agree with the data, isn't it? It's in the name.
- rcme 4y agoEvery theory is a retrofit. A useful theory is also predictive.
- rqtwteye 4y agoMOND 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.
- throwawaymaths 4y agoThat's a false equivalence. MOND has made several predictions before they were observed (external field effect, linear Tully fisher relationship, early galaxies). I think LCDM's made fewer if any predictions.
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- dave333 4y ago[flagged]
- BillSaysThis 4y agoI'm not the least bit qualified to judge this but if true, mind blown.
- lalalandland 4y agoI watched a few videos about variable speed of light. I know nothing about this but it is fun to ponder different explanations for Dark Matter, Dark Energy etc.
- HideousKojima 4y agoYou may like my silly theory (made with zero evidence) to bring back the Big Crunch Theory. Imagine that spacetime is a sphere, and the Big Bang happened at the "north pole" so to speak. All matter will eventually meet back together and recombine at the "south pole" after which a new Big Bang will happen. Absolutely zero evidence for my idea and it's probably impossible to prove anyway but it's fun to theorize.
- Tuna-Fish 4y agoThis doesn't work. The universe was opaque for the first few hundred thousand years, even if there is a cycle, we cannot possibly see it.
- dave333 4y agoWe are not looking back into the past cycle, but we see mature galaxies that date from the previous cycle.
- kolinko 4y agoWhat you're saying doesn't make sense - not even according to the bizzaro theory you mentioned. Even if there was a previous cycle, there would be no galaxies left from it to witness.
- cwoolfe 4y agoObligatory xkcd: https://xkcd.com/2622/ https://xkcd.com/2622/
- rubymancer 4y agoThat comic just made my mind bend.
- ash 4y agoThis discovery of the early galaxies seems to make “huge-looking iPhones far away” xkcd obsolete.
- starik36 4y agoDoes this mean that big bang either didn't happen or happened in a different way that we think of it? Or happened far earlier than we think it did? Complete layman here.
- rossdavidh 4y agoI think it's safe to say that it is still uncertain, but few (not zero) astronomers believe that it means the Big Bang didn't happen.
- downrightmike 4y agoWe have lots of theories, but we'll never be certain as we will never see back to the BB. Everything was hot plasma for 370k years after the BB. We can get maybe that close, but no further. We are still exploding anyways.
- pndy 4y agoI'm not an expert but from what I understand, scientists observed the very distant galaxies which shouldn't be visible according to most popular model of the universe evolution. And if these observations will be confirmed then we might get more accurate model which totally differs of the most popular one the scientists agrees upon. Far distant young galaxies should be seen as "red", but these aren't and that's the issue here - JWST captured these very bright. It's possible that the universe evolves in a different way and Hubble's law doesn't applies https://en.wikipedia.org/wiki/Hubble%27s_law https://en.wikipedia.org/wiki/Hubble%27s_law
- russdill 4y agoIncomplete/unconfirmed data is showing some discrepancies for what our tentative models of the early universe predict. The data could be wrong or misinterpreted, the models could be wrong, incomplete or misinterpreted, or the could be fundamental problems with the very foundations of cosmology. The models we have of early galaxy formation are very incomplete and based on very little data. It's exciting to get data that will discover new things about the early universe and help refine those models.
- jayzalowitz 4y agoI may be stupid, but considering that the models of galaxy stability are based on a universe where we are made from star stuff and not energy stuff, is it not possible that they formed way quicker with less complication because it was basically only hydrogen and empty space?
- jchanimal 4y agoThanks that blew my mind, had to go tell the folks in the next room. Cool perspective. Where can I learn more?
- college_physics 4y agoI 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" in a more economical way. I don't know if this generation of telescopes will get us there but it feels that this is a plausible outcome over the next 1-2 decades. Which would be very exciting :-)
- barbazoo 4y ago> 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?
- Enginerrrd 4y agoI'd say not a chance. GPT3 can regurgitate, and, in my opinion, even use knowledge, but I don't think it can synthesize knowledge.
- mikepurvis 4y agoI think it's a bit more subtle than whether it can synthesize, because clearly it can produce seemingly new work. But what it definitely cannot do is seek new abstractions. It can't be curious about an inconsistency and probe its own knowledge for possible resolutions, or design an experiment that might shed further light in an unknown area. It can't even play a board game after ingesting the rules to it, much less identify contradictions or problems in such a ruleset. And a board game is a tiny microcosm compared with the laws of physics. It's conceivable that one or more scientists could work in conjunction with an AI to help augment their own abilities, co-pilot style, but I don't think we have a picture yet of what exactly that kind of thing would look like.
- jononomo 4y agoI've always wondered where the universe is.
- djfobbz 4y agoThanks to Adobe, the universe and all of its galaxies have now been found!
- jscipione 4y agoRIP Big Bang Theory
- timmg 4y agoI have no idea if it is the end of the Big Bang Theory, but I think it would be super fun if it is: * It doesn't have a negative effect on anything if it turns out to be wrong (other than some theses). * It would be pretty cool to get a sense for how fallible we are So I'm rooting against Big Bang Theory just for the experience of it :)
- sebzim4500 4y agoDepends what you mean by the big bang theory. The theory that the universe expanded almost from a point will probably survive forever, but ΛCDM might not survive the decade.
- DesiLurker 4y agoCue Laugh Track
- bcaulfield 4y agoGreat news. Finding stuff that doesn't fit into the current model and we need smart people to get to work understanding may be the surest sign that the JWST is invaluable.
- Waterluvian 4y agoThis reminds me of how when you’re right, you don’t learn much. When you get it wrong, you learn a ton.
- gitfan86 4y agoWe have known that the current model of physics is wrong for a long time. But the main focus has been on math. "If only we could figure out this formula, then we would understand everything" It seems much more likely that we are not missing a formula but a basic understanding of reality. Much like the early astronomers trying to find a formula for the movement of the sun and planets that put Earth at the center of the universe
- andrei_says_ 4y agoI really like this comparison. But isn’t the case with modern physics that we are getting something like 8 of 10 things right? So that’s a lot of correct triangulation - and throwing the current understanding out would throw all of that away - and potentially rearrange things.
- gitfan86 4y agoThe Ptolemaic System was also mostly correct at predicting the movement of celestial bodies. https://en.wikipedia.org/wiki/Geocentric_model#Ptolemaic_system https://en.wikipedia.org/wiki/Geocentric_model#Ptolemaic_sys...
- pleb_nz 4y agoYou learn more from mistakes and being wrong no doubt about it. I remember some billionaire saying 15% of the decisions you make each day should be mistakes otherwise your not trying and you're not learning.
- atemerev 4y agoSomething is wrong with the cosmic distance ladder. Space is anisotropic, or gravity interacts with itself somehow. The distances are not what they seem to be. I think this will eventually be the solution to the galaxy rotation / dark matter problem.
- zmgsabst 4y agoOur who claim that things are isotopic seems in conflict with what we see: https://www.quantamagazine.org/asymmetry-detected-in-the-distribution-of-galaxies-20221205/ https://www.quantamagazine.org/asymmetry-detected-in-the-dis... https://www.newscientist.com/article/2280743-enormous-strands-of-galaxies-in-the-cosmic-web-appear-to-be-spinning/ https://www.newscientist.com/article/2280743-enormous-strand... Personally, I think this is strong evidence that primordial anyons were inflated — and we’ve failed to account for the energy these stored from inflation. https://en.wikipedia.org/wiki/Anyon https://en.wikipedia.org/wiki/Anyon
- 1970-01-01 4y agoI've often wondered if matter from another galaxy is behaving the same way it does here on the macroscopic level, but varies at the atomic level.
- jfengel 4y agoIt's pretty clear that it's the same at the atomic level as well. The spectra look exactly like they look here. They're red-shifted, but the gaps between the peaks are exactly the same. That comes from the atomic level, the way the electrons are arranged within the atom. If something were different at the atomic level, it would surely change the characteristics of the light they give off. The only way to see what we see would be if there were two things different, that somehow counteracted each other in the things we can see but were nonetheless different in some other factor we can't observe. That's not impossible, but it would be a bizarre coincidence.
- 1970-01-01 4y agoDoesn't spectra come from the Rydberg constant, which is set by several other universal constants? https://en.wikipedia.org/wiki/Rydberg_constant#Alternative_expressions https://en.wikipedia.org/wiki/Rydberg_constant#Alternative_e...
- jfengel 4y agoYes. If any of the constants were different, or the formula were different, we'd see it.
- xwdv 4y agoOk, so if the Big Bang Theory is bunk, what’s the next leading alternative creation theory?
- sebzim4500 4y agoSomething which sounds exactly like the Big Bang Theory to a layman but whose expansion satisfies a different equation.
- robg 4y agoInstead of one big bang, imagine an infinite number of big bangs, all colliding on a cosmic scale in time and space. That’s not necessarily a multiverse, but it is a megaverse with universe as the old paradigm.
- freedude 4y agook, but what caused the big bangs? ... Genesis 1:1
- bruce343434 4y agook, but what caused Genesis 1:1? ... big bang
- SketchySeaBeast 4y agoYou've just moved the "what caused the..." question up another level and then pleaded that your new level is somehow more special than the previous level without any actual justification. It's turtles all the way down and gods all the way up.
- drdeca 4y agoSo what you do is you form a ordinal-indexed hierarchy of “why”s, And then you go up a universe level so that the class of ordinals in the lower universe level becomes an actual set and not just a class, and then you somehow (exactly how... remains to be seen) appeal to Zorn’s lemma , and construct a why-of-all-whys that explains everything in the lower universe level. And you call that thing [ERROR: NOT REPRESENTABLE].
- russdill 4y agohttps://en.wikipedia.org/wiki/Eternal_inflation https://en.wikipedia.org/wiki/Eternal_inflation
- robg 4y agoYes, just why assume a multiverse and not a megaverse? Of course, the superhero movies (which I enjoy) give an unrealistic view of what a multiverse would be.
- luxuryballs 4y agoI always wonder if light traveled billions of years to get here wouldn’t it be possible that it got distorted along the way? What if all these galaxies are just a sort of a typical pattern of what light looks like after an unfathomably long journey through space/gravity/time/etc? It could be likely that what we’re seeing is no indication of what was ever actually out there.
- jesse_faden 4y agoIt does. One effect of light passing through gravitational wells is gravitational lensing. https://en.m.wikipedia.org/wiki/Gravitational_lens https://en.m.wikipedia.org/wiki/Gravitational_lens There is also Redshift. https://en.m.wikipedia.org/wiki/Gravitational_redshift https://en.m.wikipedia.org/wiki/Gravitational_redshift
- not2b 4y agoThis is good. If we merely confirm what we expect to see, then we don't learn anything new.
- echelon 4y agoNot so sure. If we're not early ourselves, the likelihood that the universe is swimming in intelligence -- if not already part of an enormous computational fabric -- is higher. That naively seems like it would place an upper limit on Earth-originated intelligences.
- Jweb_Guru 4y agoWould that be such a bad thing?
- TheOtherHobbes 4y agoI'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 https://en.wikipedia.org/wiki/Steady-state_model
- airstrike 4y agoSpeaking of unpopular pet theories from the 1940s, I'm a fan of the https://en.wikipedia.org/wiki/One-electron_universe https://en.wikipedia.org/wiki/One-electron_universe EDIT: There's also this super fun PBS Space Time episode on the theory: https://www.youtube.com/watch?v=9dqtW9MslFk https://www.youtube.com/watch?v=9dqtW9MslFk
- Cthulhu_ 4y agoI love this theory because it's both mindblowing and yet, when you think about it, weirdly makes sense. Assuming time travel etc, of course.
- marricks 4y agoThere’s also more spiral galaxies than expected! If steady state gained favor that would be super fun, but this quote from the article seems to throw a little cold water on that. > At the same time, she notes that yesterday’s disks are different than modern ones. “They’re not today's Milky Way,” she notes. “They're turbulent, they're messy, and we need to study them more.”
- dark-star 4y agoMy 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
- delecti 4y agoThat first theory would be interesting, but wouldn't it be basically impossible to prove unless the finite repeating universe were also pretty small? We see distant objects as they were in the past, and I'm not sure we'd recognize our own galaxy a billion years ago and a billion light years away. It's actually an interesting thought experiment. If that theory were true, and assuming we could see ourselves face-on (rather than edge-on), then I wonder how far away and far back could we recognize ourselves.
- jmyeet 4y agoCosmology is one of those fields where I suspect we'll always be finding things that don't match with theory because we can never know nor replicate the initial state of the Universe. There's also a lot of fundamental questions we don't have answers on. For example: - What does space expanding actually mean? Is space stretching or is new space being created? If so, what is the mechanism for that? - Is time a fumdanental property of the Universe or is it an emergent property? - What are the fundamental intereptations of quantum mechanics [1]? And so on. The cosmic microwave background is our earliest yet observation from the Universe. Before this the Universe was really too dense and hot for radiation signatures to survive. Interestingly, we may be able to peak even earlier than that with the cosmic neutrino background [2]. But there are a ton of things about the early Universe's formation and expansion we will probably never know and will only be able to guess at with models that will always break at a certain point. [1]: https://www.southampton.ac.uk/~doug/quantum_physics/interpretation.pdf https://www.southampton.ac.uk/~doug/quantum_physics/interpre... [2]: https://en.wikipedia.org/wiki/Cosmic_neutrino_background https://en.wikipedia.org/wiki/Cosmic_neutrino_background
- myaccount0011 4y ago[flagged]
- albertgt 4y agodf = pd.DataFrame( universe ) Warning: Specify dtype option on import or set low_memory=False.
- UltraViolence 4y agoSo there could've been civilizations that are literally BILLIONS of years ahead of us? Imagine what these people know about the universe! This reminds me of the Star Wars lead-in: "A long long time ago in a galaxy far far away." It really could've happened you know!
- foxyv 4y agoWhat's even crazier is that those civilizations could have built and advanced for a 100 million years and we would never know about it because they are so far away. The light from Canis Major, our closest galactic neighbor, is older than our civilization (25,000 years). The average distance between galaxies is 1 million light years. For all we know, there have been billions of civilizations that have lasted longer than the lifetime of our solar system and we haven't even seen the light from them yet. The universe is huge!
- yreg 4y agoEarth came quite late to the party and it spawned life relatively soon after. That's why it's strange we haven't discovered any Dyson spheres/swarms (in any galaxy). Either life is indeed absurdly rare, or Dysons are impractical for some reason, or there is a way to mask heat.
- tuatoru 4y agoEarth life uses lots of different elements - at least two generations of supernovas required. Not really that late if you allow for that.
- yreg 4y agoDidn't that happen within like the first 2B years? First Sol-like systems were I think at 5B years, which would still make Earth ~3B years late to the party.
- scotty79 4y agoI don't know. Life needed almost 5bn years to get to this point on Earth. Let's say we lucked out and it almost always takes 3 times as long. Then we look like early birds in the Universe. What's more, earlier solar systems had a bit boring chemistry. We need a lot of supernova made stuff to really function so this narrows the time window. You might think that near galactic core there's a lot of really cool stuff made but I think interstellar environment might be less stable because of that and maybe life doesn't even have a 5bn years of quiet time to develop there.
- naikrovek 4y agoI don't know why articles are titled like this. it's annoying, though, I'll tell you that we are finding the exact correct number of galaxies of the exact correct ages; our expectations are wrong, or how we determine what we've found is wrong. generally, our understanding is wrong. not the rest of the entire universe.
- hapticmonkey 4y agoExperiment results that disagree with theory is EXCITING. I hope this contributes to progress and I'm giddy just imagining the model of the universe we have 50 or 100 or 500 years from now.
- Spkeat 4y agoThis can further reinforce the idea that the unobservable universe was always there and that the big bang is only a pattern of movement of the cluster of galaxies and it is only the information that has managed to arrive from our position.I want to see how big bang theory falls into an optical illusion.
- WXLCKNO 4y agoI don't know which idea is harder for me to conceptualize. That something has always existed or that it came to exist out of nowhere-ish.
- SV_BubbleTime 4y agoI suspect this is why simulation theory is popular.
- tommoor 4y agoMuch like god, that just pushes the question up one level
- whaaswijk 4y agoWhile I agree that simulation theory pushes the question up a level, that is not the case for the God of classical theism.
- bbreier 4y agoOk, 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?
- panza 4y agoThe general idea is that the set of all contingent things can only be explained by something non-contingent (ie necessary). A necessary thing, by definition, is its own explanation. "I am what I am" etc. From there, classical theists attempt to connect that necessary thing to what you'd commonly understand as God.
- scotty79 4y agoCan you do spectroscopy on images of the galaxies to see how much stuff other than heydrogen and helium there was?
- 10g1k 4y agoA 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, therefore I can state as a fact that it does nothing." Except it turned out they were all wrong, for a very long time. The appendix is not the only example of that mentality. The same has occurred when it comes to estimates of the age of the universe. When the most powerful telescope could see N lightyears, people believed the universe was N years old. Tiny gains or new images using that telescope adjusted the estimate to N.fraction years. When the most powerful telescope could see 2N lightyears, people believed the universe was 2N years old. Tiny gains or new images using that telescope adjusted the estimate to 2N.fraction years. When the most powerful telescope could see 3N lightyears, people believed the universe was 3N years old. Tiny gains or new images using that telescope adjusted the estimate to 3N.fraction years. This happens every time. Yet astronomers and cosmologists refuse to learn the lesson, and keep repeating the same mistake.
- deadbeeves 4y agoVestigiality 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.
- deleted 4y ago[deleted]
- eointierney 4y agoOur scientists are engineers and our artists are logicians. The telescopes are always amazing
- idlewords 4y agoThis was predicted by astronomer Stacy McGaugh on his super interesting blog as a natural consequence of modified Newtonian dynamics (https://tritonstation.com/2022/01/03/what-jwst-will-see/ https://tritonstation.com/2022/01/03/what-jwst-will-see/). McGaugh came to support MOND over dark matter reluctantly for just such reasons—MOND routinely predicts things in advance that dark matter struggles to justify ex post facto, usually by adding additional moving parts to the model. Whether or not you find the evidence persuasive, McGaugh's blog is worth a deep dive just to appreciate the subtleties and complexities of this kind of observational astronomy.
- schiffern 4y agoAny publications indicate whether Refracted Gravity (RG) predicts the same thing? RG has always fascinated me, since it neatly explains flat rotation curves[1] without messing up the equations for gravity too much. If some refractory effect (TBD) causes gravity to bend toward mass concentrations, then this effectively "confines" gravity into a plane. Then the propagation law becomes 1/r rather than 1/r^2. In effect it becomes a galactic analog of the SOFAR layer in the ocean.[2] Intuitively the "self feeding" effect on disk formation should accelerate the process, but I'd be interested to see a full treatment. [1] https://www.aanda.org/articles/aa/pdf/2020/05/aa35950-19.pdf https://www.aanda.org/articles/aa/pdf/2020/05/aa35950-19.pdf [2] https://en.wikipedia.org/wiki/SOFAR_channel https://en.wikipedia.org/wiki/SOFAR_channel
- whatshisface 4y ago>without messing up the equations for gravity too much. If some refractory effect (TBD) causes gravity to bend toward mass concentrations, then this effectively "confines" gravity into a plane. Then the propagation law becomes 1/r rather than 1/r^2. There are objects like globular clusters and dwarf galaxies that lie outside the galactic plane, but are not that far away. If our galaxy's gravity was confined to its plane, you would expect nearby external objects to move differently from how they are observed to move. See illustration: https://cdn.britannica.com/23/4423-050-964A0A08/Distribution-star-clusters-Galaxy.jpg https://cdn.britannica.com/23/4423-050-964A0A08/Distribution...
- SaintSeiya 4y agoMaybe, just maybe the Universe is infinite and eternal? and the big bang never happened?
- nuker 4y agoThe Universe AI is trolling us.
- luisapic 4y ago[flagged]
- 8bitsrule 4y agoSome more interesting food for thought: >The classical big bang cosmological models describe gravitation by Einstein’s general theory of relativity. These models are able to treat the matter content of the universe quantum mechanically where appropriate, but they do not take into account the interplay of quantum theory and gravity.... The earliest universe was presumably quantum mechanical through and through, and we can no longer describe its initial conditions in a classical language. We must instead treat the whole early universe as a quantum system and formulate its initial conditions in the language of quantum mechanics.... Quantum gravity theorists have not shied away from the challenge. At present there are some half a dozen contenders...." https://www.einstein-online.info/en/spotlight/quantum_cosmo_path_integrals/ https://www.einstein-online.info/en/spotlight/quantum_cosmo_...
- deleted 4y ago[deleted]
- xyzal 4y agoArticles 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.
- yipbub 4y agoSame, 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.
- Cthulhu_ 4y agoI'm sure there's a catchy phrase for that kind of thing, intellectual cottagecore maybe?
- jstummbillig 4y agoIt was beautiful and unexpected that this was not a "but"-one-up or "but"-and-here-is-why-you-are-wrong.
- ankit219 4y agoI 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 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 universe is expanding, so is solar system. Turns out that is not the case. The distances have been more or less fixed. (i thought sun would be losing some mass, weakening gravitation for that to happen, nothing like that). - Exo-planets. - a lot of nuclear physics. - Parallel universe theory according to quantum mechanics. - gravitational waves (how to measure ripples in spacetime https://www.wired.co.uk/article/catching-cosmic-rays-virgo-interferometer https://www.wired.co.uk/article/catching-cosmic-rays-virgo-i...) - Theories around nuclear fusion and how ML, High Temp super conductivity and more precise chips are making advances possible. And so on. Will add one special mention to this: https://www.quantamagazine.org/why-this-universe-new-calculation-suggests-our-cosmos-is-typical-20221117/ https://www.quantamagazine.org/why-this-universe-new-calcula... (this universe exists because it has the highest entropy is a layman summary of the article)
- beefield 4y agoSorry for an likely ignorant question, but can someone ELI5 why we are confident that evereything in universe is less than 13 billion years old or whatnot, and not just redshifted beyond recognition?
- twojacobtwo 4y agoAs I understand it, the most basic calculation came from modeling the Cosmic Microwave Background temperature changes in reverse time. If I recall correctly, that runs into a discrepancy that requires the addition of inflation to account for it.
- Synaesthesia 4y agoOne of the great things about JWST is it can observe galaxies that are so distant, they're red-shifted that theyre in the IR spectrum.
- mr_mitm 4y agoBecause you can literally see the remnants of the big bang. Basically, if you look out far enough, you see a wall of plasma from a time where the universe was so hot and dense that light couldn't travel freely. It's called the cosmic microwave background and is impossible to explain in a static state universe. Before you get to the wall, you first see younger and younger stars (which we can tell by their composition, which influences their spectra), then a region which is void of galaxies (because it is such a young region of the universe that galaxies hadn't yet formed), and then said wall. Not only that, but the CMB's properties, like its frequency spectrum or its tiny anisotropies match what you would expect to an astonishing degree. https://en.wikipedia.org/wiki/Cosmic_microwave_background https://en.wikipedia.org/wiki/Cosmic_microwave_background
- astroH 4y agoI have to say, this article is exceptionally disappointing. As someone who works in this space, there are numerous misleading depictions about the state of the field. Almost any respectable simulation shows that disk galaxies are widely present at very early times. This is simply an argument of angular momentum conservation and these rotational states are simply more transient at early times compared to the local Universe. "Yan found 87 distant galaxies behind the galaxy cluster SMACS 0723" --> this is not true. They found 87 galaxy candidates. To be fair to the article, they do note that these await spectroscopic confirmation but experts only believe those with spectroscopic confirmation. Everything else is tentative and we don't yet have good numbers on confirmation rates. Finally, the Yan et al candidates are wildly inconsistent with almost every other estimate of high-redshift galaxy samples. You can see a comparison in Table 4 here: https://arxiv.org/pdf/2212.06683.pdf https://arxiv.org/pdf/2212.06683.pdf. They claim more than double the number of high-redshift sources compared to everyone else. JWST data is still very new and hard to both reduce and analyze. One particular problem is correlated hot pixels which can appear as very high-redshift sources. I don't know if this impacts the Yan et al paper but just an example of something that is not 100% straightforward to deal with. I highly recommend people take this with a healthy amount of skepticism until everything has a spectrum.
- gala8y 4y agoHonestly, thank you very much for this comment. As a lay person, I very often fall into taking such news as solid, as am kind of hoping for some great breakthroughs in cosmology (broadly speaking). Thanks for providing details. "One particular problem is correlated hot pixels" has a nice, cooling effect on me and I get the idea that it is an unsolved issue (kind of get it). Same with "experts only believe those with spectroscopic confirmation" - fair enough. An antidote for getting fooled in this way by such articles (or YT video beating some popular notions over and over) is to read core material (like books) and seek some actual lectures, I think. That's a pity you can't skim some topic and have it right. You just can't and it only fills you with fake knowledge.
- ngcc_hk 4y agoThe need of counterpoints and different views are important especially in academic field. But some debates got us lost as well. I would not say bad against YT but more about lack of quality one. Hope that will come. Take an example of MONO discussed below. One claimed it is right but wrong in other prediction. “ So MOND does predict more galaxies at high redshift however it also predicts earlier reionization than LCDM which it turns out not to be true and the mass function of clusters is not what we see purely based on X-ray temperatures. So getting one thing right at the expense of many others doesn't make this particularly viable.” But the major discussion shifted to dark energy and refracted … and totally ignored that wrong predictions by mono … it is just hard to follow the threads. But more discussion may help.