JWST's "too massive" galaxy problem solved?! | A non-universal IMF

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Remember those overmassive galaxies that JWST found that people claimed proved "the big bang never happened?" when in reality it was just that we couldn't explain how they'd got so big? Well, turns out those galaxies probably aren't that massive after all. In this video we're chatting about one assumption (called the Initial Mass Function of stars) used to calculate their masses needed a bit of a tweak...
#jwst #astrophysics #bigbang
My previous video on these massive galaxies when they were first found: • JWST has found MASSIVE...
** REFERENCES **
Steinhardt et al. (2023; new IMF for early universe) -arxiv.org/pdf/2208.07879.pdf
Boylan-Kolchin (2023; massive galaxies tension with λ CDM) - arxiv.org/pdf/2208.01611.pdf
Sneppen et al. (2022; temperature dependent IMF) - iopscience.iop.org/article/10...
Labbé et al. (2023; 6 massive galaxies in JWST data) - arxiv.org/pdf/2207.12446.pdf
Rana (1987; the initial mass function of stars) - articles.adsabs.harvard.edu/p...
Smith (2020; review on varying IMFs) - www.annualreviews.org/doi/pdf...
Hopkins (2018; review on how IMF is measured) - arxiv.org/pdf/1807.09949.pdf
Kroupa & Weidner (2003; Milky Way and local galaxies IMF) - iopscience.iop.org/article/10...
JWST observing schedules: www.stsci.edu/jwst/science-ex...
JWST data archive (with public access!): mast.stsci.edu/portal/Mashup/...
Twitter bot for JWST current observations: / jwstobservation
00:00 - Introduction
00:56 - Our best model of the Universe
03:14 - JWST's overmassive "impossible" galaxies
04:12 - How we measure the mass of galaxies
06:15 - The initial mass function
08:59 - How the IMF affects JWST's overmassive galaxies
11:16 - Is the IMF different in the early Universe?
13:43 - New estimates for the masses of these galaxies
16:33 - What's next?
17:33 - Brilliant
18:42 - Bloopers
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👩🏽‍💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford (Christ Church). I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars.
drbecky.uk.com
rebeccasmethurst.co.uk

[@busomite]

I can’t recall if you’ve done it before, but including photos of the lead researchers each time their paper title was shown is a wonderful addition. Putting a face to the name and research is wonderful. More scientists need to be humanized and personalized, imo.

[@blackdereker4023]

That would be a great idea, but some researchers are not famous enough to have their photo available in the internet.

[@mahanehsani1246]

same "thank you!" from me.

[@jaredknapp8886]

I feel the same way about the blind guy in the Vegas hotel bathroom. Shout out Kevin. Thank you for the hand towels and cologne sample.

[@onebylandtwoifbysearunifby5475]

"Video Killed the Radio Star." "Video Killed the Radio Star."

[@khhnator]

but then how i can picture ever single paper being written by dr. strangelove?

[@ShannonLooper]

What i love about your presentations, you always point out the assumptions and unknowns in models. That's "honest science", vs some people who are attached to particular models and defend the assumptions and unknowns.

[@tHarvey303]

Great video Dr. Becky and very well explained! Couple of points, since this is what I work on. 1. In Labbe's updated paper, they also fit with Steinhardts modified IMF templates and find very poor fits to many of these galaxies, likely because the spectral shape of the templates is very different (they tend to be very blue in the UV due to an assumed low dust content), which is quite different to the very UV red galaxies selected by Labbe. This by no means is an reflection on the IMF itself, but suggests to me that we need templates covering a larger parameter space (dust, metallicity, ionisation etc) with a modified IMF in order to better constrain the variety of high-z galaxies we are finding. 2. Even spectroscopy is very unlikely to let us constaint the IMF at high-redshift. It's almost impossible to do without being able to resolve individual stellar populations within a galaxy, which is only possible in the very local universe. The IMF is degenerate with pretty much every other parameter constrained by SED fitting, so differences in metallicity, dust content or age of the stellar population are very hard to distinguish from a changing IMF. I do believe it is likely that the IMF is bottom-light at high-redshift, but I suspect this is going to remain something we just have to assume.

[@Zxqw1262]

Hi I am not good in English so I can't understand it well so I have doubt Did she said big bang is wrong or right

[@davidwarman4290]

@@Zxqw1262big bang is still correct

[@Zxqw1262]

@@davidwarman4290 thanks👍

[@tomc.5704]

It feels intuitive that a hotter, denser early universe would have a higher proportion of larger, brighter stars -- so much so that I would be shocked if our local IMF could be applied

[@trevinbeattie4888]

I love how every question that occurs to me while watching is eventually explained in the video. ❤

[@AnnoyingNewsletters]

Same 😁 It seems to happen a lot for me with science communicators.

[@DrBecky]

🥳 I’ll take that as a win! But make sure in future if I don’t answer all your questions to pop them in the comments 👍 some I miss because I’m too deep in the science to know if people are wondering about something

[@AlphaGatorDCS]

@@DrBecky Is it possible there is NO Dark Matter? Quantized Inertia by Dr. Mike McCulloch shows how it isn't necessary by levering horizons to alter inertial mass. It shows that the very low acceleration of stars in EVERY galaxy's outer edge is at the same distance from the central black hole where the Unruh radiation is the same wavelength of the cosmic horizon.

[@jimbobur]

Same here, I came to the comments about to ask about the assumption made about the initial mass function being the same in all galaxies (including distant/older ones) and then had my question answered in the video 😄

[@reasonerenlightened2456]

@@DrBecky How much space was created before light was able to travel through it?

[@bodhimofo]

As a former academic, I really love the way you break down the methods sections of the papers you reference.

[@Riogrande1964]

Former academic here, too - this is science communication and teaching at an outstanding level

[@nerfherder4284]

It simply annoys me when scientists claim that there is dark matter because it needs to be there to make the equations work. The universe is definitely not an equation. To think from our armchairs on Earth we believe we have an understanding of the universe is soooo totally human 😂.

[@Zxqw1262]

Is big bang erong

[@igorbednarski8048]

​@@nerfherder4284"dark matter" is simply a placeholder to refer to an inconsistency between how we know gravity works and the observed behaviour of the galaxies - it means that either there's mass that we can't see or gravity works differently at large scales. We still don't know which is true. You might as well call it "Steve", we don't know what it is, we just know that something is going on.

[@Rcoutme]

Yeah, I had a feeling that it was either: 1) that the physical laws were different in the early universe or 2) that somebody forgot about the fact that conditions were different in the early universe

[@JamesFaction]

Yeah. I mean, i don't know that much but i do know that the larger the star, the shorter the life... and early on matter was a lot closer together... So I imagine it would be safe to assume that average stellar mass would be much larger in the early universe

[@georgesheffield1580]

Religious logic ???

[@crowcreates6925]

A great video with clear scientific information and no clickbait drama like many other videos on the same subject!

[@ariedekker7350]

Thank you for taking the time to convey this story.

[@jaker721]

Dr. Becky, I used to be very much into astronomy, but the interest kind of died out for me with time. You have pretty much single-handedly reignited my interest in the subject, so, thank you. I have never heard of the UIMF before, and I think it's fascinating.

[@shannonmiley9003]

When I hear that something huge and alarming has happened in the cosmos, I always tune in to Dr. Becky. Thank you so much, Dr. Becky, for helping me understand new discoveries without the histrionics.

[@mr-boo]

First video I’ve seen of yours. Great stuff, love the way you simply explain these things in a storytelling fashion. Will be back for sure!

[@GuitarGuyATX]

This is such a wonderful time to be alive and interested in science! Thank you for your excellent explanations.

[@jerelull9629]

It's SO obvious the good doctor is enthusiastic about her work -- as an astronomer AND as a science communicator, which she does so well. How her EYES lit up when she described getting different results than the best-guess theories predicted.... No disappointment that there might be something NEW to learn!

[@smlanka4u]

The matter and antimatter collisions could happen if material energy beams collided and made them, during a Big Crunch.

[@smlanka4u]

A Great (Maha) Aeon (Kalpa) is the duration a cyclic expansion and contraction process in this observable universe according to Eastern knowledge systems.

[@Ziegen-Sauger]

Outstandind Dr. Smethurst! Thank you. This lesson is expectacular. Just amazing explanation, data, graphics and the presentation.

[@ian_b5518]

Bravo, this was both a clear and understandable presentation. Excellent work Becky.

[@kylemelinkovich8675]

Love your work! Recently switched from another space news channel to yours. Ty for doing a complete dive into new theories and findings!

[@bimmergeezer]

Dr. Becky, I finished your book. What a joy to read! It cleared up some confusion that I had on black holes and their formation. Now, if we could just figure out what flavor they are!

[@tabularasa0606]

They should be chocolate!

[@johnberkers434]

They'll be mostly sour, given the sour taste is caused by protons (Hydrogen Ions), usually in acids.

[@Ryan-ff2db]

@@johnberkers434 Muriatic acid actually has a sweet taste as well. We used to power wash masonry buildings using a pressure washer with a muriatic mix. It would eat up and put holes in our clothing, so I imagine it wasn't particularly healthy but yeah it mist always had a sweet taste to it.

[@DonsArtnGames]

Yay! I FINALLY get to watch one of your videos less than an hour since you uploaded. Can't wait to absorb the information you throw our way.

[@damienbosse]

Such a great video. You do a great job of explaining things clearly and being real and excited about where we can learn more!

[@dket2571]

Absolutely brilliant piece of work, Well explained. Covering a complex topic and reducing to basic terms.

[@JohnHighman]

You explain things so well. Thank you.

[@jimf5262]

Thank you.. a nice clear explanation of something I'm just beginning to grasp! .. you're amazing!

[@amitkasliwal2115]

Again and again Dr. Becky I can not admire enough your ability to explain complex topics in such lucid convincing language for all us to understand it so well! Hats off to your Scientific Spirit and we all are so lucky to have you! Thank you so much! 🙏🏼🙏🏼🙌🏻🙌🏻

[@trevorrufli3971]

Thank you Dr Becky, you are amazing at describing complex things, thank you so much. Going to buy your book right now!

[@Vort_tm]

I love science and explanation heavy videos (sorry Night Sky News). I'm curious to know what challenges people can come up with to that two stage fit (we all know the best part of science is trying to break it)! Thank you so much for keeping us updated on any developments around this!

[@jeffsnell4254]

This was such a good explanation, thank you so much!

[@danielETouma]

I love the way you explain things. Just fantastic!

[@muhammaddaniyal4966]

I started reading your book about black holes.Gonna buy it soon .I love how u explain stuff in simple terms for ppl who are interested in space

[@hrafnfaedhir]

Another great episode Dr. Becky! As i was watching the episode, I couldn't help but wonder if the relative abundance of metals in the early metal-poor universe could also affect the distribution of the IMF? Great job. Love how you explain the models that are used to extrapolate these huge complex theories and tensions.

[@tinetannies4637]

Such a watchable channel. Informative, entertaining, and Dr. Becky is so likable. I leave feeling enlightened and in a better mood than when I came.

[@the_third_edition]

Oh, good video. This helps me understand things better than some of the talks I have attended in the past.

[@Dixy3]

Dr Becky, you are such an exciting young lady with so much enthusiasm to teach the world through your podcasts. Thank you again for your presentation, as always very much appreciated and inspiring to everyone who listens to your KZbin channel 😊. Best of luck with your research into black holes. I honestly hope JWST gives you much more data into your chosen area of science 🙏.

[@happyhome41]

Most interesting and mind expanding episode. Thank you !

[@tdoubt100]

Wow. Thanks for explaining this and the assumptions about the IMF. Science at its best.

[@nicejungle]

Awesome explanations about IMF. Thanks !

[@TheJimSkipper]

The current model was based on the limited and faulty data available at the time. The sooner it gets scrapped and replaced, the better.

[@JasonLynn7865]

I love her videos. She loves the pursuit of the truth and she is great at explaining difficult subjects. I was so happy to see how thrilled she was with JWST launch and discoveries.

[@Theyrewrong827]

@@candysgames323 Totally agree, much more experienced scientists are having sleepless nights and starting to admit if the model is wrong then everything for the last 70 which is built on that model is completely wrong. This becky is like a deer in headlights, totally indoctrinated in unproven theories that are now getting exposed as nonsense once actual evidence is coming in.

[@threewestwinds]

You discuss the effect of CMB / gas temperature on the IMF, which all makes sense. Would we also expect to see an effect from the lower metallicity of the early universe? It's my understanding that heavier elements limit the rate at which gas can dissipate heat as it collapses, which seems like it ought to change the size of stars formed by early galaxies.

[@NullHand]

I think it is the other way around. High "metalicity" promotes cooling. Basically it gives a lot more options for radiating at different and especially lower wavelengths, because all the new elements add spectral emission lines that a plain Hydrogen Helium mixture wouldn’t have. Hydrogen fires are very scary in a lab because they are invisible, since most of their major spectral emission lines are in the ultraviolet. A higher "metalicity" fuel like a hydrocarbon lets you know it is burning from a great distance because it can radiate all over the visible and ultravio,et spectrum.

[@threewestwinds]

@@NullHand Ah, I was misremembering, thank you!

[@threewestwinds]

@@NullHand I'd think it would be the opposite? Hot gas can *radiate* at any wavelength - see how stars are basically black bodies - but can only *absorb* specific wavelengths. So heavier atoms would absorb and re-radiate lower wavelengths, making the gas more opaque to that energy and trapping it in the cloud, vs. pure hydrogen where only the hydrogen absorption lines are trapped.

[@NullHand]

@@threewestwinds No. Spectral lines are just a transition in energy states by electrons. They happen both ways, when the electron absorbs a photon, it jumps up an energy level, and it can emit an identical photon by jumping down that same transition. The spectral line will be the same frequency (in the same spot on the spectrum) whether it is an emmission line or an absorption line. A large gas cloud in space will be in a balance of forces, with the mutual gravity of all its atoms trying to pull it in, and the rare collisions among its atoms pushing it back out (gas pressure). As a cloud collapses inward, it becomes more dense, the collision frequency goes up, and the average speed does as well (adiabatic compression). This tends to slow down collapse. Now, if the atoms within this gas can find a way to radiate away some of their thermal energy (speed), then the pressure will drop, and gravity can regain the edge and the cloud can collapse further. Adding elements more complicated than H and He lets a cloud make molecules of a wider variety of shapes and vibration modes. These perform the same sort of quantum jumps as atomic orbital electrons, but at much lower energies. These spectral lines are in the infra-red (or radio), are broader, and are much more efficient at radiating away the smaller energies available from thermal motion. This lets a cloud with a higher "metalicity" cool more efficiently, and contract faster. Once the cloud is sufficiently polluted with "metals" (Carbon) that it can form "dust" this process hits a whole other level of turbocharged cooling ability.

[@threewestwinds]

@@NullHand I stand corrected, thank you. And I was in fact misremembering - kzbin.info/www/bejne/aqG2hqeNd86oeJY is where I got the idea, and I had it exactly backwards.

[@datoming]

Thank you for your easy to follow discussion & explanation.

[@cornflake75]

I wish I unserstood more about the mathematics and theories in detail, but you have such an amazing talent to describe this to an amateur like me. I recently bought your new book and just started reading. Just like your videos, very captivating and just the right amount of information for "normal" people like me !

[@joachimkoenen3952]

Dear Becky! Thanks a lot for your insights into this topic. As you mentioned most mass in a galaxy is cdm. But how does this contribute to galaxy formation beside gravitational interaction. How cold was cdm anno 500M. What was it's density. What its distribution. What its contribution to the total energy. Just some questions struggling my head. Thanks Jo

[@garymathis1042]

If the universe contradicts our carefully constructed theories, then the universe is wrong.

[@Mr.Anders0n_]

The question is, who's gonna teach it a lesson?

[@janewayofchaos3255]

More like it means our theory has to be better understood. The larger galaxy than expected doesn't even contradict the big bang theory, but it does say we may have to check on a few of the equations related to it.

[@Slidezy]

The universe should know better! Bad universe!

[@chandrasekharlimit4547]

Our theories are carefully constructed, but we do know they’re not perfect, if you look at papers, you’ll see uncertainty values, we take in account how wrong we could be :)

[@thgeremilrivera-thorsen9556]

More like "two of our theories contradict each other".

[@moresoysauce5489]

First time here, fantastic video. Subscribed!

[@petereldred1541]

so many more questions, love your work

[@springinfialta106]

Whoopee! We scientists LOVE IT when we get new data that challenges our current theories.... but not if it completely undermines our understanding. So we need to fiddle around with our theories to make them fit the new data. Whew! It seems like we can fiddle enough to keep our theories mostly in place. Fudge. er Dark... Matter saves the day!

[@infinitumneo840]

When I consider the theories of the formation of the universe, I am reminded of a song by Simon and Garfunkel that says, "The more you reach your destination, the more it slip sliding away." The universe is much older and more viser than any of us, and she proves it all the time.

[@jonathanhinkel8813]

100% super informative and easy to understand. Thanks much!

[@fmdj]

Omg recording the video with no sound must have been so frustrating 😅 Glad you re-made it, similarly I might re-watch it cuz I'm pretty sure there's a lot I haven't understood :)

[@takashitamagawa5881]

Excellent video. So many sensational videos right now about the breaking of the Big Bang theory. A lot more data has yet to come in and a lot more analysis needs to be done. Great to listen to Dr. Becky describe science in action.

[@Paulancar]

For me this videos are pseudoscince very sensaciolims big bang theories.

[@takashitamagawa5881]

@@Paulancar A lot of talk right now about traditional cosmology being wrong as the initial observations from the JWST come in. Dr. Becky Smethurst has been a scientist in the field of Big Bang Cosmology and she would hardly claim that all the big questions have been settled. I will be watching her videos to get her views and analysis of the data from the JWST as it comes in.

[@Beef8Cake]

The universe is much older and bigger then we believe it to be. And the scientific community really doesn’t like change that much, or to have previously “proven” theories proven wrong or incomplete. So they will fight it for as long as they can.

[@mjprelic]

Bingo. They rush out a fast answer to faith their model, jsut so they don't have to change. How can you solve this issue so fast?

[@mjprelic]

*fit

[@MrKillerno1]

Love you Becky (I am not the only one) and how you make movements with your hands all the time, makes you... so lovely... oh, and of-course what you explain in all your video's is so bright and clear to understand, love to see comments from people who actually learned something... 🥰😍😘

[@spacebread501]

Dont you already get another, top-heavy IMF just from the lower metalicity? Or is this already accounted for? Awesome video btw. Super interesting stuff.

[@nosuchanimal6947]

came to the comments to ask about metalicity affecting the imf, too! :D

[@NoahFriedman]

I was going to ask the same question. It seems to me like it's not overfitting to take metalicity into account for the IMF.

[@edwardrhoads7283]

Plus I wonder if you have some number of population III stars also if it is that far back and those stars would be 200-300 solar masses and so extremely bright.

[@arctic_haze]

A very good explanation from a real expert on the galaxy evolution. Thanks! Also, I notice your great mood. Good for you!

[@frankharr9466]

That is really neat. Thank you and I hope this continues to work out.

[@javiertorres9114]

Awesome video. Thank you

[@arvehalseth1490]

I'm actually an economist, so sorry to intrude into the discussion here. After that apple fell down long ago, physicists have built an impressive set of models that have been tested empirically. Economists still have a lot to learn from you and your channel is inspiring to follow. The problem arises when something outside the realm of experience suddenly becomes observable, such as with JWST. This is something you always emphasize; that's when it gets exciting and that's when all the assumptions can be tested. Nevertheless, figures are published in articles that say that an observation cannot be physically possible. A better formulation would have been something like the result is not consistent with the assumptions made in the relevant paper. Your video is an excellent example of how different assumptions easily lead to different results. Saying that something is not physically possible should mean going back to the model rather than publishing a sensational scientific paper.

[@petermoller8337]

Black Swans

[@nerfherder4284]

Ironically, my economics professor made it very clear that economics was a religion and anyone telling you it's a science is lying. Concepts like ceteris paribus and the idea that the only way their theories make any sense is by ignoring everything but a few variables is so completely unscientific that it's laughable. Economics is simply a variation on psychology and economists are just soothsayers and gurus with little actual science to back up their statements. I am not saying economics is useless as I believe psychology is very important, but just not a 'hard' science.

[@ronammologist16]

Well said. She does not inspire my confidence.

[@silvercloud1641]

The Science Asylum addressed this in 2 minutes in the last live stream, "It's Our 10-year KZbin Anniversary! Ask Me Anything Live!" @47:09

[@joshualeamer6117]

Said what I'm to stupid to say.

[@samael-thebringer01light66]

Not only do you get a sub from your awesome science but also due to the fact that you added your bloopers to the end of your video. Great Work!

[@DrBecky]

Welcome!

[@linmal2242]

I hate peoples bloopers; yeah, i GUESS THAT i GET IT, MAKING ONE SEEM MORE HUMAN-ISH, BUT STILL THINK THAT ITS UNNECESSARY. (Why do I keep hitting the caps key? Is it my typing or the keyboarsd? Yes, my 'typing' !)

[@samael-thebringer01light66]

@@linmal2242 I like to think of it that it shows even though she is very intelligent that she is humble and makes mistakes. I personally have not have the perception of many people doing that in their videos so this was a new experience for me.

[@clarencemcduffie8598]

I really liked this video. Your explanations were thorough in detail and easy for me to understand. I enjoy cosmology but my only schooling on it was astronomy 101. I do try to keep myself up to date on the topic. As you went on I even guessed where it was heading...... Universal IMF definitely needed refining. I want to know more so keep us updated on this when more data gets verified and cataloged. The JWST is a marvelous tool we are going to learn so much I can't wait.

[@AsmodeusMictian]

Thank you for yet another awesome video :)

[@MCsCreations]

Honestly, dr. Becky, I think it's a fantastic opportunity. Because if everything only confirms what we already know... We're never going to learn anything new. Yeah, the Lambda CDM model has its issues... But I would be really surprised if we've got everything right from the beginning. Anyway, stay safe there with your family! 🖖😊

[@icaleinns6233]

Initially I thought she was going to discuss a new Tom Cruise adventure with the Impossible Mission Force! 🤣 Turned out to be much more informative!

[@jayjohnson3732]

I wondered if I was the only person who’s mind went to Mission Impossible when she said “IMF. Thanks for joining me in pop culture bingo.

[@icaleinns6233]

@@jayjohnson3732 YW! Took me a bit to figure out exactly how to word that, though! 😁

[@vigilantcosmicpenguin8721]

I was confused what the International Monetary Fund had to do with this.

[@leoruda]

Thank you for their level headed non hyped explanation. Took me a while to get to you. You've have my subscription and thanks.

[@PhilW222]

A very complex issue, very well explained!

[@Jatheus]

Oh man, I have recorded entire videos with no mic/audio before... that sucks. Wouldn't the IMF just be a function of how much stuff happened to be nearby when it started clumping? Or is it that we don't know that and we want to know? Unrelated... well, maybe related... if the universe stopped expanding and started contracting tomorrow, would that be instantly observable, or would it take millions or billions of years for us to even notice? Great video as always!

[@UncommonSense-wm5fd]

How could the Universe stop expanding, what mechanism would facilitate this? The question is a non-sensical hypothetical.

[@Jatheus]

@@UncommonSense-wm5fd Well, considering we don’t know by what means it is apparently expanding and accelerating now, I really couldn’t say. Dark Energy is just a placeholder we add in to fit the observations plus our current understanding. But if it were to stop expanding, and we wouldn’t know for millions of years, I think that is worth considering, even if we don’t take it seriously. We know our current understanding is incomplete.

[@UncommonSense-wm5fd]

@@Jatheus We do know what the catalyst for expansion is, the Big Bang, the Universe is constantly expanding due to this event. The increased acceleration, which is thought to have occurred 9 BYA is as of yet unexplained however the Universe has never stopped expanding.

[@elio7610]

AFAIK, the cause of the expansion is still unknown, "the big bang" is just another way to describe the expansion and not an explanation.

[@UncommonSense-wm5fd]

@@elio7610 The Big Bang is recognised as the cause for rapid expansion, we're unclear as to the events that preceded it.

[@patrickmchargue7122]

I also worry about overfitting the data. Adding new parameters is an easy fix, but may mask the underlying cause.

[@glenchapman3899]

Agreed, and pressure then mounts until some new lion arrives in the field and generates a paradigm shift in our understanding of the problem. Been happening since Ptolemy, dont see it stopping anytime soon

[@gonegahgah]

Except when do people finally stop and start saying this went into crazy land a long time ago! Trying to mask over conflicts with extensions or some new abstraction is the recurring normal.

[@pauls5745]

I love Dr. Becky makes all these concepts and papers understandable

[@kohtalainenalias]

Greetings from Finland. Well explained and articulated :)

[@justinadams5446]

Another paper has been published showing that the JWST and Tolman Test prove the tired light model, not LCDM, is the correct one (and this time it’s NOT by Dr. Lerner). It also shows it’s not valid to use a bottom-light IMF because the light coming from those galaxies isn’t blue enough. Ray Fleming called you out on this in his video. Would love to hear your thoughts on it. kzbin.info/www/bejne/m2jJdqp4dp6kh6c

[@sthomas6369]

I thought it was believed that early stars (first generation) were more likely to be massive. So isn't the universal IMF time-variant?

[@michaelsommers2356]

Being very massive, they would have been very short-lived, and I don't think we can see any of them, even with JWST.

[@hagerty1952]

So what we need is a "Hubble Constant" version of the IMF?

[@declandougan7243]

@S Thomas Don’t mean to be rude but that’s the entire point of the video. She’s talking about a study in which researchers investigated if the IMF varies with time.

[@Lamster66]

@@declandougan7243 Not being rude either but Dr Becky starts of by saying that the original results were derived by assuming a univeral IMF that wasn't time varient so the OPs point was valid(ish).

[@Lamster66]

@@michaelsommers2356 Doesn't that depend on how far away it is? I thought that was the whole point of JWST to try to observe the formation of galaxies closer to the time of the big bang So whilst those largers stars may well have gone now we are seeing the light or the red shifted microwaves from 12 or 13 billion years ago? To see what's there now you'll have to wait another 30-40 billion years as that's how far away it'll currently be due to expansion.

[@quantumradio]

Thank you for a great video. You explained the cutting edge astronomical papers in a simple yet thorough, consistent, and analytical way. BTW, my vote would be to send sophisticated space spectrometers in all future astronomical space missions. Spectrometers provide indisputable results and we know so much about element shifts, e.g. Zeeman splitting for B fields, hyperfine structure, L.S, S.S, coupling on the Hamiltonian, etc.

[@furballphoto9627]

Thank you for all the great information. I’ve been seeing all those crazy videos about how the JWST broke the Big Bang theory and how it can see other universes and so on. I’ve been waiting for a proper scientist video to see what it’s actually found (to the best of our understanding, of course).

[@Valdagast]

There's a new (to me) astronomy KZbinr called acollierastro. Her research is about bar formation in galaxies. That sounds interesting - possible collab? She also apparently discovered that there's no reason to think there's a planet IX.

[@victorspresence1263]

Hey V! But there is a planet XI! He runs this little nuked world!

[@alancham4]

So we’re 100% sure that the observed redshift is because the universe is expanding?

[@charliesteiner2334]

Merely 99.9% or so.

[@michaelsommers2356]

Nobody is 100% sure of anything.

[@ianw5439]

There are no other valid alternatives. Tired light is Crankology 101.

[@aurelienyonrac]

Either the space is expanding or matter in it is falling on itself. Ya know, like we would be in a black hole. Either what we are measuring is getting bigger or the unit we are measuring with is getting smaller. That flexibility of mind reveals that dark energy is just gravity. Yes pushing and pulling are two opposit forces. But if a guy infront of you pulls your car, and a guy behind you pushes your car.... Well, they make your car go forward. Meaning it is the same force seen from a different perspeciv.😅

[@alancham4]

@@aurelienyonrac say what now...I'm asking about the doppler redshift. Shouldn't we be able to observe expansion more locally like on what level is the expansion taking place since some things are coming towards us. So that's gravity within a limited area but that whole area is expanding? Just way out far it's expanding?

[@pnutbteronbwlz9799]

Fantastically described video. I appreciate how you don’t use the news to gain an advantage and manipulate.

[@laughingoutloud5742]

New subscriber here - I love your explanations and really appreciate the Bloopers! Cheers from Canada

[@EatCheese11]

Webb is brilliant

[@johnmeredith6890]

No. the men and women who made it are.

[@JHClemmontine]

What if "the big bang" is just an event that happens when a black hole decays and our universe is many degrees larger than we ever could have imagined?

[@earnric]

Nice explanation!

[@CloudhoundCoUk]

Dr Becky a fabulous presentation.

[@bbittercoffee]

I really feel like i'm gonna be at my death bed and I'll hear some news of scientists discovering that their old models were wrong and that a new model has been made to better fit every observation we've had Also, that difference at 14:01 being almost a BILLION really cracked me up for some reason

[@Palancar]

Seems like until we understand what dark matter and dark energy really are, we're not going to answer some of these questions. Love your videos!

[@jacobsmith4284]

Dark matter and energy are theories to try and explain another theory called the Big Bang.

[@doug8515]

Or realize 'dark matter' and 'dark energy' are just in the imagination

[@Palancar]

@@doug8515 by "understand" I mean we understand the very real effects we are observing, whatever the cause. I agree the names are terribly confusing.

[@bobbywade3282]

That first Blooper was one of the most relatable things I've ever heard

[@jeanouellet5512]

Congrats for the capacity to make a very specific field of study intelligible for non-experts. And I love the systematic scientific doubt, it's what gives science its legitimacy.

[@jamm8284]

Hi everyone

[@JNo-sk5mz]

They just refuse to admit that the standard model is clearly flawed, "it must be the amount of time it takes galaxies to form", instead of, the universe is far older if not infinite 😑

[@ianw5439]

So, all you have to do is explain the CMB and its age, yes? Get on with it. Nobody else seems to be trying since years ago. Even steady-state proponents (I think there is one left!).

[@chriswebster839]

Just because you don't like the explanation given, that doesn't mean they're "refusing to admit it".

[@Tsudico]

Perhaps you should get some education in metrology and error tolerance. Then you might begin to understand that we never expect anything to *perfectly* fit so there will always be flaws. What matters more is how accurate our models are to what we are seeing. So if you are saying that the current theories that make up cosmology are flawed, you must provide an alternative cohesive set of theories that gives better accuracy than what we have. Anything less isn't scientific.

[@JNo-sk5mz]

@@Tsudico Perhaps you should take your snarky remark’s elsewhere, and continue to watch as the James Webb continues to lay waste to the Big Bang theory

[@Tsudico]

@@JNo-sk5mz Hey, if you have a theory that perfectly fits all the data without the Big Bang, I am all ears. Just make sure you provide the formulas and data used to come to your conclusions so it can be reviewed just like all other science.

[@Kneumann1991]

The first statement about jwst's images was actually that there were galaxies further than expected. Then when a work around came about to make it fit the big bang model. It was then realized that some of the galaxies were too big to be that early on in the universe. How many times are you going to skew the data to fit your old model before taking all the new hard data and start building a new model?

[@hankfowler8194]

Thank you for that explanation of IMF and how we often have a "knee jerk" reaction new data that doesn't fit our earlier models. As the cosmic dust settles, many calmer minds will analyze the data and the whole field will be better for it.

[@schmerlski]

Sorry DrBecky, you are too good for me to let this go uncorrected. At 12:02 you said less of the smaller stars. I think the correct words would be fewer of the smaller stars. Less light, fewer stars. Less blood, fewer knives. Less rain, fewer clouds. Do you see the pattern? I believe proper grammer matters for scientists educating the general public on complex topics, no matter how reduced or simplified the concepts. Thanks

[@robbie_]

Cosmologists have added yet another epicycle to their grand model of the unvierse.

[@ianw5439]

And which particular unscientific cult do you follow? Flat earth? Creationism?

[@robbie_]

@@ianw5439 Do I need to follow one?

[@Tsudico]

As Dr. Becky explained in the video, in the paper where they talk about removing the universal aspect of the IMF there were concerns about trying to overfit the data. I think they presented a good argument as to why their solution actually follows Occam's razor. Occam's razor isn't about being *just* the simpliest solution, it is about being the solution with the most accuracy for the least amount of variables. In the case of epicycles, it was found that epicycles were not the most accurate for the given number of variables and that orbits around the stellar mass were more accurate while needing less variables. If, in the future, it is discovered that a dynamic IMF is not actually required, but is added complexity that isn't as accurate as some future theory, then it will be discarded. Just like epicycles were (although epicycles still have uses elsewhere).

[@robbie_]

@@Tsudico Yes, I know what the problem with epicycles was. I'm just very sceptical about the jenga tower that is cosmology.

[@adriancopping1253]

Thank you Becky 👍🙏

[@fluxrider7027]

That was possibly the best blooper reel I've ever seen.

[@babygrand734]

Thank goodness we have many highly intelligent people who can invent a new epicycle to preserve the Big Bang theory. Ptolemy would be proud.

[@leesmith2347]

Like all the best theories, it is subject to evolution :)

[@michaelsommers2356]

What a magnificent display of ignorance! Nothing in this video remotely resembles epicycles. Not even close.

[@UltraDoug]

IMHO, you saying that the Big Bang happened is just as silly as me saying that it didn’t. We simply cannot make final conclusions based on the the insanely limited information we have. It would be like blindly putting together a puzzle with a trillion pieces and coming to a conclusion regarding the final picture based on the 10 pieces we have put together. We just….don’t…..know. Every new bit of information changes our view. I love the discoveries, but disdain the unintentionally arrogant “conclusions”. - end of line

[@ianw5439]

_"IMHO, you saying that the Big Bang happened is just as silly as me saying that it didn’t. We simply cannot make final conclusions based on the the insanely limited information we have."_ You mean the prediction of the CMB, and then its detection, beginning in 1964 with Penzias-Wilson, followed by ever more accurate observations from space, from COBE, WMAP and Planck, all confirming the BBT predictions to very high significance? Want to tell us what the CMB is from?

[@UltraDoug]

@@ianw5439 Oh, didn’t realize you had all the puzzles pieces. My bad.

[@ianw5439]

@@UltraDoug Huh? Want to deal with what I wrote? Word salad doesn't cut it in science buddy.

[@adamc1966]

@@UltraDoug totally agree with your original post. Big Bang has become a religion that can't be questioned.

[@UltraDoug]

@@ianw5439 the discovery of CMB was a big deal and accepted by the scientific community as ‘evidence’. Evidence is just that, is not a conclusion. Sorry you take offense at the mere suggestion of the Big Bang not happening, maybe it did. My original point was not to slam, but rather to state that with each new discovery we get deeper understanding. The JWST has proved that in just a short time of gathering…..evidence. That enough meat, buddy, or was that just more salad?

[@docholiday8029]

Excellent video. Subscribing now.

[@o2bavr6]

Excellent video.

[@idanburs5869]

So, the lesson here is to allow the science to work itself out through replication, testing, alternative modeling, peer review, etc., RATHER THAN immediately latch onto sensationalized news headlines that knowingly distort single sources for purposes of being first, getting clicks, increasing advertising revenue, and fomenting misinformation also known as fake news.

[@nicolinzini520]

Sorry to hear about the microphone situation, thanks so much for doing it all over again. Your videos are much loved and appreciated.

[@samwell6915]

Nice vídeo!

[@iainpaul9177]

Love the content

[@aforementioned7177]

Plenty of Woo Woo out there on the Internet. I have been waiting for you to make a video on this. 😀