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.
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.
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.
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.
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
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
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 😂.
@@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.
🥳 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
@@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.
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 😄
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.
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.
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!
A Great (Maha) Aeon (Kalpa) is the duration a cyclic expansion and contraction process in this observable universe according to Eastern knowledge systems.
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
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.
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!
@@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.
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.
@@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.
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.
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! 🙏🏼🙏🏼🙌🏻🙌🏻
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.
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.
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!
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.
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.
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.
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.
@@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.
@@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.
@@NullHand I stand corrected, thank you. And I was in fact misremembering - th-cam.com/video/4pSUtWBiuB4/w-d-xo.html is where I got the idea, and I had it exactly backwards.
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! 🖖😊
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 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.
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.
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.
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 !
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
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
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.
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' !)
@@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.
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
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.
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!
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.
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. th-cam.com/video/e7fEwBA9qQE/w-d-xo.html
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.😅
@@AurelienCarnoy 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?
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?
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.
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... 🥰😍😘
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 TH-cam 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 🙏.
I just think it’s kinda weird that no matter how many times the current consensus is overturned or altered that afterwards everyone goes right back to talking about the new current theories like they are indisputable facts. I’ve watched countless videos, lectures, documentaries etc about the Big Bang and the early universe before jwst and they all talked about the dark age of the universe as absolute fact. I mean we don’t even have a unified field theory so it’s pretty likely we are missing something really substantial or making some substantial mistakes. Maybe someday when we have enough energy m theory can be proven and we will have figured out dark matter and energy but idk would have been nice to not need a phd in physics to know how tenuous our understanding of galaxy formation was.
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 :)
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.
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
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.
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?
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 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
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.
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.
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?
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.
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
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!
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?
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).
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.
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?
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
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.
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.
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.
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.
I've heard redshift talked about so many times bu I don't think anyone has ever said it was because of the expansion of the universe in such plain terms. That makes so much more sense now!
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.
spontaneous generation (eg fruit flies arising from rotting fruit) is known to be impossible but something much bigger and more complicated (everything) is thought to have begun spontaneously. I simply accept that there is something much bigger and more complicated than we can understand and let it be. Mostly because knowing with certainty how the universe began does nothing to help us solve the problems of the world today. We have people dying on the streets and lunatics destroying countries left and right. Bigger problems a lot closer to home. How about we get our house in order before we look so far away for things that won't actually change anything for the better here and now.
![CAMPปลิ้น | รวม Highlight 2024! PART [1/2]](http://i.ytimg.com/vi/6hnvNnvYloU/mqdefault.jpg)
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.
That would be a great idea, but some researchers are not famous enough to have their photo available in the internet.
same "thank you!" from me.
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.
"Video Killed the Radio Star."
"Video Killed the Radio Star."
but then how i can picture ever single paper being written by dr. strangelove?
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.
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.
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
@@Zxqw1262big bang is still correct
@@davidwarman4290 thanks👍
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.
A great video with clear scientific information and no clickbait drama like many other videos on the same subject!
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
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
Religious logic ???
As a former academic, I really love the way you break down the methods sections of the papers you reference.
Former academic here, too - this is science communication and teaching at an outstanding level
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 😂.
Is big bang erong
@@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.
I love how every question that occurs to me while watching is eventually explained in the video. ❤
Same 😁 It seems to happen a lot for me with science communicators.
🥳 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
@@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.
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 😄
@@DrBecky How much space was created before light was able to travel through it?
Thank you for taking the time to convey this story.
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.
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.
This is such a wonderful time to be alive and interested in science!
Thank you for your excellent explanations.
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!
The matter and antimatter collisions could happen if material energy beams collided and made them, during a Big Crunch.
A Great (Maha) Aeon (Kalpa) is the duration a cyclic expansion and contraction process in this observable universe according to Eastern knowledge systems.
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.
Outstandind Dr. Smethurst! Thank you. This lesson is expectacular. Just amazing explanation, data, graphics and the presentation.
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
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.
The current model was based on the limited and faulty data available at the time. The sooner it gets scrapped and replaced, the better.
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!
They should be chocolate!
They'll be mostly sour, given the sour taste is caused by protons (Hydrogen Ions), usually in acids.
@@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.
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.
@@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.
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.
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?
*fit
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!
🙏🏼🙏🏼🙌🏻🙌🏻
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.
Black Swans
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.
Well said. She does not inspire my confidence.
The Science Asylum addressed this in 2 minutes in the last live stream, "It's Our 10-year TH-cam Anniversary! Ask Me Anything Live!" @47:09
Said what I'm to stupid to say.
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!
You explain things so well. Thank you.
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.
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.
Hat Licht im Raum und um die Sonne dieselbe Geschwindikeit? In Space and around the Sun has Light the same run as on earth cause mass?
Wow. Thanks for explaining this and the assumptions about the IMF. Science at its best.
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.
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.
@@NullHand Ah, I was misremembering, thank you!
@@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.
@@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.
@@NullHand I stand corrected, thank you.
And I was in fact misremembering - th-cam.com/video/4pSUtWBiuB4/w-d-xo.html is where I got the idea, and I had it exactly backwards.
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! 🖖😊
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!
Bravo, this was both a clear and understandable presentation. Excellent work Becky.
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 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.
Most interesting and mind expanding episode. Thank you !
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.
came to the comments to ask about metalicity affecting the imf, too! :D
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.
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.
I love the way you explain things. Just fantastic!
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 !
This was such a good explanation, thank you so much!
A very good explanation from a real expert on the galaxy evolution. Thanks!
Also, I notice your great mood. Good for you!
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
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
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.
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!
Welcome!
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' !)
@@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.
I also worry about overfitting the data. Adding new parameters is an easy fix, but may mask the underlying cause.
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
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.
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!
Oh, good video. This helps me understand things better than some of the talks I have attended in the past.
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.
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.
th-cam.com/video/e7fEwBA9qQE/w-d-xo.html
So we’re 100% sure that the observed redshift is because the universe is expanding?
Merely 99.9% or so.
Nobody is 100% sure of anything.
There are no other valid alternatives. Tired light is Crankology 101.
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.😅
@@AurelienCarnoy 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?
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?
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.
Absolutely brilliant piece of work, Well explained.
Covering a complex topic and reducing to basic terms.
Webb is brilliant
No. the men and women who made it are.
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... 🥰😍😘
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 TH-cam 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 🙏.
I just think it’s kinda weird that no matter how many times the current consensus is overturned or altered that afterwards everyone goes right back to talking about the new current theories like they are indisputable facts. I’ve watched countless videos, lectures, documentaries etc about the Big Bang and the early universe before jwst and they all talked about the dark age of the universe as absolute fact. I mean we don’t even have a unified field theory so it’s pretty likely we are missing something really substantial or making some substantial mistakes. Maybe someday when we have enough energy m theory can be proven and we will have figured out dark matter and energy but idk would have been nice to not need a phd in physics to know how tenuous our understanding of galaxy formation was.
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 :)
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.
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
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.
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".
Such a great video. You do a great job of explaining things clearly and being real and excited about where we can learn more!
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?
Thank you for their level headed non hyped explanation. Took me a while to get to you. You've have my subscription and thanks.
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!
I’ll look out for it!
@@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
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.
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.
Did you provide the link mentioned around 4:40? If so, I can't find it.
First time here, fantastic video. Subscribed!
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?
Awesome video. Thank you
How much smaller was the volume of spacetime then? I think a less diffuse spacetime leads to higher gravitation in the early universe.
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.
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
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!
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?
I love Dr. Becky makes all these concepts and papers understandable
Thanks!
Love your work! Recently switched from another space news channel to yours. Ty for doing a complete dive into new theories and findings!
Greetings from Finland. Well explained and articulated :)
Sorry to hear about the microphone situation, thanks so much for doing it all over again. Your videos are much loved and appreciated.
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).
That first Blooper was one of the most relatable things I've ever heard
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.
Excellent video.
Subscribing now.
Fantastically described video. I appreciate how you don’t use the news to gain an advantage and manipulate.
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?
Thanks
It makes sense to me that in the early universe where matter was much more dense bigger stars was much more commonly produced
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
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.
What an awesome and inspiring video and channel. Thanks!
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.
Thank you Dr Becky, you are amazing at describing complex things, thank you so much. Going to buy your book right now!
Plenty of Woo Woo out there on the Internet. I have been waiting for you to make a video on this. 😀
Finally someone gets to the point, without beating about the bush!
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.
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.
I've heard redshift talked about so many times bu I don't think anyone has ever said it was because of the expansion of the universe in such plain terms. That makes so much more sense now!
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.
I honestly can’t think of anything more exciting
spontaneous generation (eg fruit flies arising from rotting fruit) is known to be impossible but something much bigger and more complicated (everything) is thought to have begun spontaneously.
I simply accept that there is something much bigger and more complicated than we can understand and let it be.
Mostly because knowing with certainty how the universe began does nothing to help us solve the problems of the world today. We have people dying on the streets and lunatics destroying countries left and right. Bigger problems a lot closer to home. How about we get our house in order before we look so far away for things that won't actually change anything for the better here and now.
I love how you channelled your best Sean Connery when saying "Lamda SheeDM"
A very complex issue, very well explained!
New subscriber here - I love your explanations and really appreciate the Bloopers! Cheers from Canada