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

[@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.

[@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?

[@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👍

[@fedfraud.protection.servic2557]

Very interesting. And informative! Total pleasure reading something from someone that actually knows what they're talking about. Question: W(obs) is generally in the NIR and lower for VHZ objects, correct? Would it be possible to down convert and use frequency synthesized heterodyne tuning to get more precise spectra? Variable fine filtered CCD imagers maybe? I think there's been some thing out about strong N lines in VHZ galaxy spectra, so maybe modeling could bump up metalicity just to see what happens? Probably a lot of Supernova stuff going on initially, anyway. Seems to me that initial SFR has to be astronomical early 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 ???

[@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.

[@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.

[@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

[@fedfraud.protection.servic2557]

I know, right? It's like, why even model it? My understanding is there are strong N ii lines in the 2B year old galaxies which might indicate that they're not first generation, unless the Big Bang kicked out a bunch of N and Si with all that H and He. Maybe the problem is there aren't enough qualified C++ and FORTRAN 😂😂 programmers to generate proper modeling. Can't adjust the IMF on the models? Or the nitrogen content of generation 1 galaxies. Mmm.

[@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.

[@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.

[@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.

[@Ziegen-Sauger]

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

[@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

[@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.

[@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.

[@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.

[@JohnHighman]

You explain things so well. Thank you.

[@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.

[@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!

[@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.

[@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!

[@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! 🖖😊

[@geekwithabs]

Being able to look further back into time as you look far away is more like a "window into the past" than a "time machine".

[@angel19785]

It makes sense to me that in the early universe where matter was much more dense bigger stars was much more commonly produced

[@drsatan7554]

Entropy was higher at beginning of universe. Entropy being lost means energy is becoming less usable While Entropy was high, the forces which formed galaxies could do so easier

[@tdoubt100]

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

[@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.

[@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.

[@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.

[@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?

[@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.

[@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.

[@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.

[@arctic_haze]

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

[@EmergentUniverse]

I have enormous respect and admiration for Dr. Becky. Tragically, there was a missed opportunity circa 1898 - 1927 to discover the architecture of nature. There is a very simple and parsimonious ASSEMBLY architecture with point charges that was never considered. It works beautifully and is a plug in foundation for general relativity and quantum mechanics. Sadly the implications of this architecture will cause a massive transformation in cosmology, astrophysics, and astronomy. Everything sort of works similarly, but now we need to take out the distortions and inversions and look at things from a very simple frame of reference where everything makes total sense and is obvious. This all revolves around the implementation of spacetime and how Einstein's curvy-stretchy spacetime and its contents produce behaviours we observe such as inflation, expansion, and the role of SMBH.

[@danielETouma]

I love the way you explain things. Just fantastic!

[@jeffsnell4254]

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

[@happyhome41]

Most interesting and mind expanding episode. Thank you !

[@nthingtoofear]

We've moved to the "make the universe work for the model phase" I see. Like we did with concentric circles for a geocentric orbit or the "aether" in later models. Can't wait for the new model to come up in 50 years or so as this one gets stretched and twisted by new observation.

[@malthomas987]

Wow. Thank you Becky. You are now my "Sky at Night". You don't say things like "the Hydrogen atom is a single proton"... You treat your viewers with intellectual respect. Anybody else hear think the same way?

[@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.

[@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

[@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.

[@znet2723]

Science has a habit of adjusting the models to fit new discoveries. Sometimes you need to assume the model is proven wrong and come up with a new model.

[@bryanandhallie]

The terms Quantum Electrodynamics (QED) and Quod Erat Demonstrandum (Q.E.D.) being two of the most eloquent and decisive statements in all of physics, mathematics, and philosophy happens to be one of the most poetic things I think I've ever seen

[@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

[@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?

[@PdWOLFG4NG]

We need to let go in thinking of models that compliment each other, the big bang was probably not a "big bang" we need to finally start thinking about what happened before the big bang .. something i was never allowed to ask being a kid in school... What a world

[@TVirus91]

Galaxies these days: "Did you just assume my IMF?"

[@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?

[@EatCheese11]

Webb is brilliant

[@johnmeredith6890]

No. the men and women who made it are.

[@bobbywade3282]

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

[@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... 🥰😍😘

[@ronaldkemp3952]

Dr. Becky, remember in 2021 when I asked you what would happen if the JWST discovered fully developed galaxies in the early universe, some galaxies larger than the Milky Way galaxy but further than 14 billion light years away, and you told me it would become a paradox in cosmology? Well, the reason why I asked this question back then is because according to my calculations they determined the most distant galaxies would be fully developed and much larger than the Milky Way, but further than 14 billion light years away. I knew at the time it was conjecture because all the models of the universe were predicting young, small underdeveloped galaxies in the early universe. And according to general relativity's look back time, and the age of the universe, nothing is supposed to exist further than 13.8 billion light years away. So, I had to wait for the JWST to image the galaxies before my calculations could be proven correct. Low and behold, it's exactly what the James Webb discovered. Go figure right?

[@andrewdl6824]

I thought the reason the early universe was so hot was because the matter was so densely together but those early galaxies detected are sitting alone in space.

[@corythomas909]

Amazing video! How many galaxies have the same IMF as the Milky Way? What led to our assumption of a universal IMF? Have we verified all of our local cluster or what?

[@earnric]

I'm just sending a paper to ApJ tonight on a related topic: searching for Pop III stars with JWST. I argue for a top-heavy log-normal IMF. I found evidence for it in an earlier paper that looks at CEMP-no stars here in the MW halo. So funny that I found your channel tonight!

[@DrBecky]

I’ll look out for it!

[@earnric]

@@DrBecky Haha! Thx... it's at ApJ which means 2 months minimum! LOL... however, I'll prob get it on the ArxiV once i have a ref assigned. "Predicting the Characteristics of the Earliest Galaxies", Sarmento & Scannapieco

[@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!

[@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 🙏.

[@rnbwd7741]

I've been watching tons of videos on this topic, but what surprises me the most is that there is such a strong consensus that our models of cosmology are correct. Our observations of light are extremely limited, and our cosmological theories are maybe 50 years old. We don't know what dark matter is, or if it is even matter. We also know that the microwave background radiation has slightly different properties than what we've observed in galaxies for the expansion of the universe, which means that some fundamental properties of matter could have changed between when the background was formed, and when galaxies formed. We base soooo much importance on the redshift of galaxies, but like there are theories indicating that JWST is only looking 5 billion years away, not 12 billion years away. The cause of redshift should be questioned way more than it currently is. There shouldn't be this strong of a consensus that we understand the exact age or expansion of the universe. There should be more variables, and scientists have way too much ego to overstate their claims or their error margins. IMHO the error margin could be huge, like the universe could be twice as old or half as old, and the distances we are observing might not be as far away as we think. It blows my mind that most cosmologists believe that their theories of cosmology are correct, when dark matter and dark energy cannot be explained and fully formed galaxies exist (immediately after) the big bang? Something doesn't make sense. It's either dark matter, the fundamental constants changing, or both.

[@shawns0762]

Most people don't know that Einstein said that singularities are not possible. In the 1939 journal "Annals of Mathematics" he wrote "the essential result of this investigation is a clear understanding as to why the Schwarzchild singularities (Schwarzchild was the first to raise the issue of General relativity predicting singularities) do not exist in physical reality. Although the theory given here treats only clusters whose particles move along circular paths it does seem to be subject to reasonable doubt that more general cases will have analogous results. The Schwarzchild singularities do not appear for the reason that matter cannot be concentrated arbitrarily. And this is due to the fact that otherwise the constituting particles would reach the velocity of light." He was referring to the phenomenon of dilation (sometimes called gamma or y) mass that is dilated is smeared through spacetime relative to an outside observer. This is illustrated in a common 2 axis relativity graph with velocity on the horizontal line and dilation on the vertical. Even mass that exists at 75% light speed is partially dilated. General relativity does not predict singularities when you factor in dilation. Einstein is known to have repeatedly spoken about this. Nobody believed in black holes when he was alive for this reason. Wherever you have an astronomical quantity of mass, dilation will occur because high mass means high momentum. There is no place in the universe where mass is more concentrated than at the center of a galaxy. According to Einstein's math, the mass at the center of our own galaxy must be dilated. In other words that mass is all around us. This is the explanation for the greatest mystery in science, the abnormally high rotation rates of stars in spiral galaxies (the reason for the theory of dark matter) the missing mass is dilated mass. According to Einstein's math, galaxies with very, very low mass would not contain dilated mass because they do not have enough mass at the center to achieve relativistic velocities. This has recently been confirmed with 5 very low mass galaxies, all having normal star rotation rates. The shape of a galaxy is common in nature. From atoms to our solar system, the overwhelming majority of the mass is in the center. The same must be true for galaxies. Where there is mass there is energy. The night sky should be lit up from the galactic center but it isn't. The modern explanation for this is because gravitational forces there are so strong that not even light can escape. Einstein's answer would be because the mass there is dilated relative to an Earthbound observer. The main reason why we cannot see light from the galactic center is because there is no valid XYZ coordinate we can attribute it to, you can't point your finger at something that is smeared through spacetime. Or more precisely, everywhere you point is equally valid.

[@AnimeFanatic5602]

I've always assumed that very early galaxies would be made primarily of population 3 stars, which would certainly change the IMF compared to today.

[@concepcionkennedy5183]

That’s the beauty of Science, it’s not dogmatic. It’s willing to change based on evidence.

[@JohnnyPhenix11]

Finally someone gets to the point, without beating about the bush!

[@aforementioned7177]

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

[@ian_b5518]

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

[@RodMartinJr]

Interesting! Bottom light works in our favor by NOT having a lot of "legacy," low metallicity stars cluttering up the galaxies. A bias toward heavier stars would mean more supernovae, and better chemical enrichment of later generations of stars.

[@orbatos]

The upside is that imf ranges can be adjusted for, so performing calculations based on a constant can be compensated for as it's expanden on with more nuance.

[@Darisiabgal7573]

BTW, lets give a thanks to Becky for providing this deeper analysis. So much you-tube content now adays is shallow 1 minute click baity stuff. Its truely a blessing to see providers taking the time to provide enlightening content So my basic critique, not of the analysis but of the logical framework. The problem with expansion is its based on inflation as a pretext. This period of expansion is followed by micro inflation we call dark energy. And we live in that epoch, whereby that is our understanding of spacetime. So the way I view spacetime is as an equilibrium state where the components of the field through a very long process that started with the end if inflation create what appears to be a glassy smooth field, we call gravity, in all directions out to the limits of the universe. So, if I were to drop a lead ball into the center of a very large pond then at the center the perturbation in the wave function would be great and approaching the edges smooth. In the same way graviatational perturbations cause by two black-holes fusing 3 billion light years away is at the limit of detection here. But these mergers events are rather close to us in space and time. During the beginning of the universe these events are far in both space and time, so perturbations in the initial state flatten out to distant observers. The difference between 3 billion years ago and 13.2 billion years ago is we have discrete cause(s) that we can specify, analyze and compare. The only discrete thing concerning the period before star formation is the putative end of inflation. But there is a caveot, it appears that by 13.7 billion years ago matter formation is essentially complete and by that time the density of the matter is 10,000 to 10,000,000 times more dense than the universe today, as you stated hotter. Hotter plus more dense means a higher static pressure. The only thing that is keeping star formation in check is the gravitational force points in many directions and is not pointing at some nucleation feature. If it was not for this feature the universe should have cavitated most matter into black holes. The problem for example in black holes is that energy in space can curve spacetime to the point that a logical prediction of what spacetime does effectively stops just shy of the event horizon. And thus coming out of the end of inflation spacetime maybe not as field-like as we see it today. A granualarized spacetime can create perturbations in the future field that are too shallow, now, for us to detect but could possibly have created disconfornaties in local matter that reached low enough temperture to condense. So here is my critique in creating blacks swans based on contemporary observations of star formation. We really do not understand the nature of gravity during the transition between inflation and expansion. We are pushing the envelop of belief into science when we try to estimate what happened before the CMBR. The cause of nucleation of the first stars is not at all comparable to accretion of currently forming stars. When we make a statistical argument based on a null hypothesis we make the assumption that two sets have certain comparable qualities and that testing the hypothesis can root out significant differences. The problem of upholding such a conservative stance is based on the premise of comparable qualities. But the limitations of the null hypothes are rooted in qualifying the initial comparable. For example can a seagull swim as fast as a swordfish. The assumption is that a seagull can swim, if it cant then there are no comparables and thus comparing swim speeds is irrational application of the hypothesis. If you know that the universe is devoid of elements to begin with, you really cant compare star formation with a later period to begin with. 1. Dust formation in heavier elements proceeds faster and can form smaller stars, and celestials that do not produce light. 2 Heavier elements have more inertia and tend to produce less elastic collisions, especially in aggregate. This we can generalize that star formation with heavy elements will proceed one way, within regions with lighter elements another way, and in the early universe when pressure and temperature were higher, still a third way. As a consequence we can ask three different questions and make three comoarisons., 1. How do low metalocity stars form today and how does this process compare with high metalocity stars? 2. How do low metalocity stars form today and compare with formation of stars in the early universe? Notice I changed the question, comparing comparables. 3. What types of perturbations in densities cause low metallocity stars to form today and are such perturbations present 13.2 billion years ago? 4. What types of perturbations are present in the universe 13.2-13.1 billion years ago and what was their magnitude. Question number 4 begs the questions, without other proxies, isn't star formation a good indicator that perturbations are present. So the issue that Webb is rewriting the big-bang, but this is not the issue, the people studying the issue are seeking guidance by adding more data. This data helps the see better early states in the universe. But we need to understand that models can only go so far if their assumotions are incorrect, they cannot lead the data.

[@drsatan7554]

Wrong The inflationary theory didn't arise till after the Big Bang theory and the expansion of the universe was discovered before the big bang theory was posited. It's what inspired George Lemaître to come up with the big bang theory The rest is just more lies and nonsense from a self deluded pseudo-intellectual

[@c.b.816]

We have a lot of technology in space suits just to deal with the current temperature. Imagine going for a space walk in a blue universe twinkling with star formation and galaxies so close you can see the arms with the naked eye. Your space suit would be so different, and probably require more cooling.

[@nicolinzini520]

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

[@kohtalainenalias]

Greetings from Finland. Well explained and articulated :)

[@celestekent1236]

What is clear is a need to refigure the gravitational constant, the apparent anomalies can be explained without going off and describing something that can't be seen or measured.

[@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 :)

[@aSpyIntheHaus]

I love how you channelled your best Sean Connery when saying "Lamda SheeDM"

[@MountainFisher]

Not all scientists love it when we learn something new Dr. Smethurst. Not if the new information contradicts their preferred theory. I'm not referring to just the Steady State Astronomers who were shocked that the Universe had a beginning. You ought to see what recent discoveries in other fields has done to old information thought to be true and "iron clad" proof before electron microscopes had been invented.

[@DrBecky]

I honestly can’t think of anything more exciting

[@jasonhenson7948]

Using our galaxy and our closest neighbours to get a universal IMF sounds like taking a survey in your desk-group at primary school. Definitely have to start somewhere, but "everyone is 8 years old".

[@richiebricker]

I didnt know there is a difference in what we thought the temp of background radiation was. Ill see how much Brilliant costs and see If I can find out more

[@Oliveir51]

Most of our understanding is based on interpretation of red shift being due to speed only and doppler effect. Now we measure a tiny red shift due to photon charge interaction. And all indicates our universe is much more electromagnetic than we thought. So our theories may look coherent only on short distances

[@Alfrisssss]

Uhm, I have a question (astrophysics student here). We already know that the gas that ends up forming stars and galaxies needs to cool down, and we describe its cooling efficiency with a cooling function which IS a function of both the gas cloud temperature T and its metallicity Z. _Why would it be so bad to relax the assumption of a universal IMF_ ? I mean, at high redshift the metal content of a cloud may have been much different from one of a stellar cluster that forms in the local universe: given that metals favor the cloud fragmentation into smaller clumps, star formation may have been different in a metal-poor environment. Also, given that the gas as a whole was hotter, it is likely that the smallest achievable fragments were also forced to be larger (Rees Argument), thus the birth of smaller stars may be hindered in the high redshift universe. Maybe even the IMF is a function of Z? 🧐 Relaxing the universal IMF idea does not seem too bad to me, although other models and simulations proposed more efficient cooling methods that could also help with this “galaxy too big to be true” (😂) problem 🧐

[@markhamstra1083]

And the usage distinction between “less” and “fewer” takes another hit.

[@JungleJargon]

I have actually featured a YEC video explaining the possibility of the variable speed of light (without changing the speed of light) . I don’t expect anyone to agree with it until they can understand it. I have a thought experiment that will demonstrate what we are talking about. Hold your hands about a foot apart representing 186,000 miles. Then watch an imaginary photon travel from one hand to the other in the time that it takes for you to say “one thousand and one” representing one second. That is C the speed of light. Now spread your hands apart still representing 186,000 miles while saying “one thousand and one” as fast as you can and watch the same imaginary photon speed up as it passes from one hand to the other while maintaining the speed of light C the same as before. This is what is happening in general relativity comparing the gravitational effects of one amount of gravity with another amount of gravity in another place. You can do the same thought experiment in reverse too. You can clearly see the speed go faster and slower depending on the amount of gravity which alters both the rate of time and the measure of distance simultaneously.

[@adandap]

Given the amount of inference involved in bootstrapping local observations out to very large distance/very old times, I'm not surprised by discrepancies in cosmological observations versus models. It's nice to see some of those assumptions and inferences coming under further empirical testing.

[@J0hnnieP]

Dr. Becky's videos are ALWAYS stuffed with tons of info ... and the bloopers are sometimes funny enough to make their own videos. All-in-all, a heck of a deal.

[@s.patterson5698]

The best type of scientists are those who are humble enough to acknowledge that their knowledge is not absolute and that there are potentially other facets at work they they haven't begun to comprehend. There was a time when the best scientific minds adamantly stated the Earth was flat. All our advancement is due to the power of the human mind, but as brilliant as we might me, our acute awareness of our limitations is the fundamental key to opening futher the door to greater knowledge. Enjoyed your video!

[@dket2571]

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

[@Lucius_Chiaraviglio]

The thing that is a surprise to me about the initial mass function being different at high red shifts is that anyone finds this to be a surprise, when for many years I have kept reading about how the initial mass function had to be different in the early universe due to the lack of elements heavier than helium (except for traces of lithium) in the early universe. This effect would stack on top of the higher gas temperatures of the time (in concert with the higher cosmic microwave background at the time). Sounds like astrophysicists have gotten so stuck in their own fields of specialty that they don't pay attention to what the others are saying.

[@Flatballflyer]

My understanding of the universes expansion is that space is becoming "less dense" - the "area" of a cube of space is increasing, but the matter in that space is not increasing. So if we roll that clock back to the early universe, would that make a section of space with a critical mass more likely to collapse into a black hole because it's starting off "closer" to the "density" needed? Would that more "dense" space also put more matter within the grasp of the black holes gravity, allowing much faster growth? Or, maybe all you smart folks have already thought of this and it's accounted for in the models?

[@tonibat59]

This IMF fudging reminds me of Von Neumann: With 4 parameters, I can fit an elephant, with 5, I can make him wiggle his trunk.

[@andym4695]

"We need more data" is science-speak for "I bought a new house/car and need job security!" Seriously, this is quite cool. JWST is a seriously shiny piece of equipment. I'd say that between it and other even more powerful/specialized instruments, and assuming we don't gas ourselves to death with CO2 or perform some other blockheaded maneuver, the 2000s will be seen as a golden age in astronomy/astrophysics. What an exciting time to be in the field.

[@antjoshwww]

The beauty of space is that astrophysicysts get it so wrong and get away with it

[@stevensteven3417]

They just want a good paycheck and enjoy life as much as possible as long as possible.

[@pandora8610]

"Very rude ... I am in the middle of science" is such a wonderful response to an interruption.

[@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.

[@paulhobson4799]

It would be interesting if the JWST was to look at the place, where Hubble took it’s deep field image and compare them to see what greater depth the JWST gets.

[@dcbrown5875]

The biggest issue I see is assuming speed of light is constant…. Gravity affects it ( see black holes ,gravity lensing,ect ) so since the universe was much denser light was slower

[@phoenixskeptic7698]

I come to Dr. Becky's channel to get the real skinny on the stuff others get wrong.

[@picksalot1]

A Universal IMF seems to be at odds with often repeated statement that "The Universe is homogenous and isotropic."

[@pauls5745]

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

[@javiertorres9114]

Awesome video. Thank you

[@Sidistic_Atheist]

The +plus or -minus factors are so large, when calculating the amount of stars within a galaxy, is surely unworkable.

[@johnzuijdveld9585]

I can't say I understand everything of the science videos/doco's that I watch, but I love the 'conundrum factor,' as in: we have a proposition that proves to be wrong so now we know only 'probably' what is not, so we devise other suggestions and go through the same process as before ad-infinitum, . . . it IS progress, but not as you'd like it! lol. To me it's a folly to imagine that everything in the universe is conforming to a 'standard model' because the potential for variation is huge, we may think we know ALL of the 'laws of physics' but we probably don't, but there is salvation in that most probably there is a propensity for things to evolve as we think they should. So, then it is the differences from expectation that we should focus on. The bloopers are great because they exemplify what I said above. 😊