Dr Weinberg was my professor for cosmology, and he gave us a flawless performance of the dark matter rap during lecture. He got a standing ovation. It was effervescent and hearing that at the beginning of this video made my day
Steven Weinberg was a bigot, got to sit through him bringing a female Iranian graduate student to tears during a lecture q&a by berating her and then implying his supremacist stance by pointing out how the Muslim countries have never won a Nobel prize and probably never will while his people have a plethora. Look at his quotes on the Palestinians if you have any doubts about his supremacist views. Also saying Dark Matter has been observed and only a 'crackpot' would protest since all physicists agree on dark matter being observed is just completely wrong. You can find quotes of counterexamples everywhere from top physicists who will tell you its not been observed. Once you can prove you've measured a signal of dark matter then it will be observed. The currently fruitless search for measuring dark matter on the particle physics side doesn't look good though. Playing word games with 'directly' and 'observed' just misinforms the public and applying the repetition over and over in the video on your stance is not the best approach to such a controversial subject.
I'm not a student, engineer, chemist, or scholar; I'm a truck driver with a high school education. I just want to say I love your content. Your ability to communicate is wonderful and make the topics more interesting.
@FollowSmoke, I agree! I have heard the spiral galaxy explanation for dark matter but couldn't understand why it wasn't just a bunch of rocks. If we can't find Planet X in our solar system, despite gravitational evidence, why do we need "magic matter" for galaxies. The WMAP explanation finally offered an answer for how we know that a 'weird' form of matter exists and has since the Big Bang.
POV: You're about to add an 'other' comment, thus changing the data until that which was presented in the second video is inaccurate for the future, thus aging it like milk.
@@rayli.08 As someone whose friends tell him he's funny but tried and failed to be a comedy writer, I have to tell you that your evaluation of the comment you replied to as serious is 1000% wrong.
@@rayli.08 I've told a joke before. In my expert-ish-esque opinion, I have to wonder if you're wrong about me being wrong about them being wrong about her being wrong
It's funny: some creators use these powerful engines and elaborate animations to try and convey complicated topics more intuitively. You simply talk to us like we're in a conversation, using your hands and the occasional picture, and I always end up with a clear and manageable (even if not totally complete) understanding. You are an amazing communicator! Thank you for your content
Anyone can make a video just talking to the camera. People put so much effort into animations and editing because it's the only way to stand out. It's lucky the algo picked up a channel like this over a thousand others
8 questions to ask yourself about dark matter: 1. Do we need it? 2. What is it? 3. Where is it? 4. How much? 5. Do we need it? 6. Do we need it? 7. Do we need it? 8. Do we need it?
@@Fritz_Schlunder 1. the us government is most likely lying about aliens as they have shown absolutely no proof of their existence despite their claims. 2. unless you can explain why all matter in the universe are not moving towards each other at rapid speed due to gravity, then please do not throw the expansion of the universe out the window like that. 3. that's not how quantum fluctuation works. virtual particles aren't technically real and only arise in mathematical calculations of the quantum world. even if they did really exist they would disappear so quickly that they would have absolutely no effect on any real particles. 4. if physical components of gps satellites are being affected by low gravity then scientists would've noticed that way before they had to include time dilation in their equations. also, science is all about building and improving on what we've already known. scientists don't come up with completely new ideas when observations proves their current models wrong because it is a much safer bet to just reconstruct their current models so that it matches up with the observations. unless some truly radical observation is made that their current models cannot explain no matter how much they try to change it, or some new model is created that explains everything the old model can and the new observations as well, then it is unlikely that the current models are going to be just thrown away like nothing.
@@senvr11It's not that drastic tho lol. It is just a pretty useless but honestly pretty interesting mathematical model that happens to be fundamentally untestable so even if it is true we just will not know
@@senvr11 Yeah, I get it, but I think string theory is sometimes vilanized. It is not really physics, it is pure mathematics, but it is genuinely really interesting. People seem to think string theorists are all misleading douches and claim string theory is a waste if time. Which I feel is unfair
@@sebastiangudino9377 my issue is those who put it into physics, like i'm sure it's cool math but if it's not for this reality then i mean... cool? I can understand what you mean. My dad grew up in the string theory age and one of the consequenses is that he said quantum mechanics was just us not understanding physics. I don't blame the math for his ignorance but it's a setback
I like that you included the point about the systematic error. That the expectation vs measurement does not have the same discrepancy in every galaxy. Very important addition.
That single clarification actually totally changed my view on dark matter. I very much tend to lean towards systematic errors and underlying misconceptions as explanations for things, but that can't be the case here.
I don't get it. Why can't it just be that our understanding is wrong? In general when our observation doesn't fit understanding, how can you *ever* conclude it must be observation that's missing purely based on *how* they don't fit?
@@randomnobody660 Our understanding being wrong is one of the theories. Modified Newtonian dynamics is a set of theories relating to us just not understanding how gravity works on large scales as an explanation to dark matter observations. So far, many of the proposed MOND theories fall short on adequately explaining the variety of different observed dark matter amounts just like the systematic error theory.
@@jamesbyrd3740 and yet there were tides. Saying there are no tides because you did not believe in Posidon did not make the tides go away. Dark matter is a tide you can't explain.
This got unexpectedly very emotional for me at the end. Today was the funeral of an aunt of mine, who was one of the best hobby gardener I know. And as a matter of fact I told the people who were there how honoured I feel to have all her gardening books now here at my place to take care of them. And it was also a rough day because we couldn't take my dad with us who is at very poor health both physically and mentally. And coincidentally to how you ended your video my dad has been a ham radio enthusiast for 30 years. So very strangely I feel like somehow if I have been hugged by this video and it somehow makes me want to hug it back. This must sound strange... but I feel very strange after watching the end of your video, but actually a lot better. Just had to have you know that.
binged your channel after getting recommended the string theory video . big fan of this style of content, keep it up 😁 i was casually interested in astronomy and physics when i was younger , but i chose to study electrical engineering instead. the way you present science has reinvigorated my interest in these topics.
I binged the channel as well! It's dope, eh? I love this type of content as well. Yet when people tell me to make something similar about art, I say "ahhh who is going to listen to me talk for an hour?" Lol. And yet here I am, watching long videos with pleasure.
@@izzyonyt yeah, exactly. It's like your buddy, who has amazing stories, who you can listen to nonstop. Which is rare to me because usually I'm that buddy to everyone and rarely I encounter people with such cool storytelling on interesting to me subjects. I'm so happy to find this channel!
@@szaszm_ I feel that as well. Like, I believe that very soon she's gonna become insanely popular on RU-vid. Because there is everything: good storytelling, relatability, comprehensive explanations and genuine, funny, authentic lady who is just amazing by herself with a strong values system. It's destined to blow up.
@@TheBBQifyi’m not sure if you’re aware of the PROPER definition. so i will copy and paste it for you. “theory is a well-substantiated explanation of an aspect of the natural world that can incorporate laws, hypotheses and facts.”
I don't hate when you repeat stuff. You are (a) making a stylistic choice which is fun and (b) making things easier to understand. I get it, and please keep doing it
There's a lot to take in, so the repetition helps. The one take home message I got from this is that the dark matter is just a theory, not an observation.
@@tuomasronnberg5244 absolutely true. It is widely understood. I bet it would be boring if you were a teacher, like she is effectively being; I'm sure my high school algebra teacher was so sick of the quadratic formula she probably had dreams about murdering it with a fork. But we learned it because she kept repeating it over and over
@@georgelionon9050 I know how you feel, I grew up in a culture which associated repetition with idiocy, but found this culture to be very bad for me because in several ways it arrogantly opposes things which are good for the human brain. I had a lot of challenges to my mental health, and my culture was an obstacle to my recovery. I don't want to get into all the details, but repetition in particular is good for learning. When you hear something again, your brain refreshes the original memory and associates a new one, and may make connections with things you're thinking about at the time of the repetition but perhaps weren't when you first heard it.
@@dragon67849why did you feel the need to put this exceptionally creepy comment out there? Jeez dude, maybe read your comments before you post them and if that isn't working then my guy you gotta think about developing some kind of filter - it should be obvious why that comment is rank, and if it's not you have some introspection to do.
As a mathematician I really wanted to interact, but then I was specifically requested not to. So now instead of a compliment about how that's a perfectly reasonable handwave-y concept of why fourier is the greatest analysis tool of all time, I will be like Dark Matter and not interact with anything. PS I love your work, these are great
The fossil analogy was actually perfect! Fossils aren't the actual organisms anymore (ignoring stuff trapped in amber etc), but give us a detailed picture of what the bones (and sometimes skin and feathers/hair) looked like.
And in some cases, what the internal structures look like at a cellular level. An example being dinosaur marrow, whose structure was preserved down to the cellular level, despite the loss of the majority of proteins and DNA.
@@spvillano I'm still salty that the DNA has decomposed. I would punch myself in the face no more than 3 times to see a real dinosaur! I was such a huge dinosaur nerd as a kid. Okay, well, no, that's not accurate; I'm still a huge dinosaur nerd.
It took 27 minutes of this video for me to fully comprehend what was meant by the title, but when it clicked that 'dark matter'is *only* the phenomena amd evidence, without any explanation implied, it was a pretty cool realization. These are the observations, and the theory comes in when we start trying to explain what the dark matter actually *is*, or why it behaves the way it does.
@quark-soup that overly literal interpretation of the phrase 'dark matter' is like... the whole thing this video is refuting. We don't know for certain whether or not a form of matter is responsible for those observed inconsistencies, but the collection of inconsistencies exists, and regardless of what hypothesis you propose to explain them, it's still purely descriptive to say they resemble the behavior that would be expected if there was matter in places where we don't see matter. Explaining why galaxies exist like there is some matter near them that we can't otherwise see is the question, not the answer.
@@theta-rex that's a lot of ad hominem for a conversation about science, friend. I think you are maybe missing the point here, and that's okay, but it's not my job to explain it better than the doctor of the field who made the video in the first place lol
@quark-soup and *my* point is that you've come into the comments section of a video about a topic you clearly don't understand, and decided it was worth your time to insult a random stranger while also being wrong yourself. Maybe stop, it's just kinda sad at this point.
@justlolatthisworld7917 the fact that you think any of this has anything to do with 'religion', or belief of any kind just proves that you are thinking about this thing like a dogma yourself, and thereby completely missing the point lol
I'm a 16 years old science-lover from Brazil, and RU-vid just recommended me this amazing video out of nowhere. I've loved it. Please, continue posting stuff like this!
I'm 16 as well! Looking to go into astrophysics and finding gems like this is really helpful when you're trying to surmount the seemingly endless cliff of knowledge to understand what you're actually reading. One of the reasons I love science communication is because it bridges that gap, and I want to be good at it someday as well so that I can help people understand the concept itself instead of reading a headline with the word "breakthrough" and assuming something beneficial is going to come out of that. I think a lot of that is whats lacking right now in the field as a whole.
Have you tried more of her videos? She's one of the best science communicators to follow for the average layman imo. Very chill communication style. This channel has really been helping me get motivated to do deep dives into physics and cosmology.
"so this is when we- well not us, we werenyt there...this was before stars..." Something about this line is just hauntingly beautiful and terrifying to me
After finishing my MSc in theoretical physics I felt a burnout and been working in finance for 1.5 years barely looking at science. Finding your channel like a week ago brought back my enthusiasm and I started once again studying multiple fields by myself and I'm loving it. So thank you and keep up the amazing work
I’m glad it’s not just me. After my Bachelor’s, I wasn’t sure I wanted to do a PhD, so I’ve been in telecom. After discovering her content, I’m giving a PhD a serious rethink. She is reminding me why physics is so special
I was about to drop out from physics major because of the burnout, but i found this channel and now i'm thinking deeply about leaving the university. xd
Hey, I just wanted to give a big thanks to you for making these videos. Seeing someone being so passionate about research or also just nerding out about an interesting topic is really encouraging me to take steps towards eventually getting into research myself. I think I really needed that at the moment.
Takeaways from this video: 1. Dark Matter is not a theory 2. Dark Matter is an observation 3. You can't just throw away Dark Matter 4. 1980's Casio keyboard midi drum tracks still slap in 2023
" *1. Dark Matter is not a theory* " True. It's a hypothesis. " *2. Dark Matter is an observation* " False. People were searching for Dark Matter for decades and found nothing so far. What she shows as the "evidence for dark matter" is circular reasoning at its worst. "Gee, the Galaxies move too fast for their masses!" "Hmm, maybe they are way heavier than we thought? Due to some dark matter, you know?" "Dark Matter exists! Q.E D." " *3. You can't just throw away Dark Matter* " True. Just throwing it out won't work. The trouble is we simply can't find it, so some people start digging very deep into our actual theories.
Okay, I've found a better summary, I think: 1. Luminoferous aether is not a theory. 2. Luminoferous aether is an observation (not true, obviously). 3. You can't just throw away luminoferous aether. 4. 1860 Brahms still grooves.
She is right and wrong at the same time. "A theory explains a natural phenomenon that is validated through observation and experimentation. A hypothesis is an educated guess based on certain data that acts as a foundation for further investigation." Correct. Dark matter is not even a theory its a hypophesis. A measurement which is in conflict with the given model doesn't spawn anything. We observe the conflict and automatically make up hypophesis. The correct sentence is: "There is a conflict between the model and our observation" Thats it. Nothing more can be said. Everything beyond is already interpretation and hypophesis. Of course there are very good arguments for the Dark Matter hypophesis....but again its not even a theory. "Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe." - wiki (Edit: There is a discussion bellow about the correct definition of a theory in physics. This doesn't change the fact that Dark Matter is not an observation, as acollierastro said in the video, but an hypothesis. The observation is a model versus reality conflict. I just wanted to add this here)
I'll tell you something about the 60's and 70' as personally experienced by a particle physicist. The mystery of the rotation curves that was being occasionally mentioned at the time - departmental colloquia, reading "Sky and Telescope" (remember that?), etc. - seemed like an oddity that could wait. No one in my group of colleagues talked about it for more than 5 minutes after some interdepartmental colloqium. We - really my smarter colleagues - were busy with the "heroic" period of standard model building and accelerators. As also a lifelong amateur astronomer, I recall it also being NOT a big deal outside a university astronomy department. Only on those occasions, especially recently, when particle physicists become piqued by "bright , shiny" new things in other people's playgrounds, or, being like Oppnheimer are as true renaissance men, did attention turn back to the cosmic aspect of physics. Having faced the humiliation of a bad, oversold prospective theory (strings), theoretical physics has in the past decade basically turned to hints from the sky to make up for running off the end of the Standard Model. A little oversimplified, but clearly to me a big shift in attitude. regards DKB
Dark matter wasn't a common term until the mid 2010s, although anomalous rotation problems were noticed as far back as Vera Rubin. Now, every kid thinks it's a fact that solves everything, but it's really something that can be placed anywhere, any time, in any amount, to make some equations work. There is a theory, it is not well understood at all except perhaps by a few, and dark matter is a requirement of the theory for it to kind of, but not really fit observations.
I was just trying to explain this to my son earlier (who's 6) and told him that while we haven't figured out what dark matter or dark energy is, we can observe the effects of it. He had far too many questions though. I study computer science, not astrophysics, so I had to basically tell him I just don't know enough or understand enough to give him better answers. I think admitting "idk" is unfortunately lacking in society. Anyway, maybe one day he'll be able to explain it to me!
My dad and I have had so many debates about this stuff and it usually ends with him getting hung up on something, then me trying to explain why it works in that way, and then him not listening even when I give him a source. Good times.
fortunately scientist say 'we just dont know" often enough. Too often too my liking because it does not explain what i want to understand. But this is good for science as it keeps it honest and we know where need to focus attention.
@@L2p2 That's not true at all. The majority of scientists simply submit to whatever the consensus of their high priests is. It's a top down authoritative structure that has a lot to do in common with religions. If you question things, or apply critical thinking or alternative explanations for data, you are mocked, ridiculed, suppressed, and thrown to the fringes as a quack. If they were more honest most of the current theories wouldn't even exist.
Heads up, the audio is clipping sporadically throughout the video. Dunno if its a microphone issue or because as you said in the description you may have increased the gain too much. I recommend looking into using compressors for increasing average loudness over just boosting gain (assuming thats what you did) Great topic and great video
Came here to say the oldest audio trick in the book is to compress all vocals. I actually recommend doing two compressions one with a short attack and release and another much longer to act as a intermediate length normalizer, and then finally normalize the entire piece. The short compression is to take out the spiky staccato of hard constants and mic pops. The next one is for acting like a normalizer and mitigating things like bad mic usage (varying distance/direction) and overly dynamic speech patterns. Then in the final edit, normalize the entire piece. It sounds like a lot of effects, but it really isn't and is a fairly standard practice that goes back to reel to reel days.
@@krisspkriss Yeah, I didn't even notice anything was wrong since I run all podcasts and videos of people talking through a compressor (Thimeo's Stereo Tool).
Agreed! Apply compression instead of just gain, EQ some body into the vocals, better mic setup, pop filter, maybe a little room padding to avoid echoes.
Fun fact about Vera Rubin? Her husband would drive her to class, eat dinner in the car, then drive her home. They were both pretty busy brilliant people but found a way to spend time together every day. I just find that incredibly adorable.
Dr. Collier, You have managed to address these topics in a manner that is simultaneously (1) precise, and technical and (2) delightful and fun. I really hope you continue to produce content, because you are exceptionally good at it. Also - your extensions to standard English are hilarious and self explanatory. I hope you continue to keep your edit mode set to ‘artistically scientific’.
Mr Moessinger, you have managed to write this comment in a manner that is simultaniously (1) showing how incredibly seriously you take your own mediocre writing style (honestly, dont try so hard, its kinda strange and makes you seem unsincere, just like, talk like a human) and (2) i dont really have a 2
And I'd rather us all stop quoting and glorifying a certified creep and serial abuser who coerced and manipulated women into unsafe situations. Richard Feynman was the Harvey Weinstein of the science world and it is time we start acknowledging this reality.
@@ModernStupidity-qm3rj I've known many highly religious people who love to engage in debating everything within their religion. If you don't, you need to associate with smarter people, religious and otherwise.
I love your channel. You make it look easy to make these videos but I know it must take many many hours. I am one of the people out in the public that reads a lot about science. I have an undergrad degree in Engineering Physics and your channel really takes me back. Oh and I also own a vintage oscilloscope. Mine is a BK Precision probably from the 80s. It still works. I repair vintage stereos and other audio gear as a hobby so I do use it occasionally to troubleshoot.
I’m about to get my PhD in wavelike dark matter (axions if you’ve heard of them) and I’ve been looking for good explanations of dark matter to send my undergrads. Thank you so much for making this - it’s exactly what I needed! Especially your explanation of Fourier analysis.
@@DowJonesDave Arms in spiral galaxies are observed to rotate at the same speed regardless of distance from the center of the galaxy. However luminous mass decreases as you go further from the center of the galaxy. Therefore how is it this happens because of time dilation? Why do the arms rotate at the same speed even when they have less luminous mass? If time dilation is behind dark matter then why can we observe less stars, but they still have the same rotational speed. "Because time dilation makes them release less photons" ok but this still doesn't explain anything. Less photons overall still means we can see less mass further out from the center right? So why do the arms move at the same speed regardless of distance when we can observe them containing less stars. I'm so confused why time dilation matters at all when we can see with certainty mass decreases the further out you go. By your logic the arms aren't affected by time dilation as much as the center so they appear heavier due to the center having photons be emitted over a longer period?
@@DowJonesDave After googling things to get a better understanding of this I think I can refute this better. 1. We measure a galaxies mass in a variety of ways. Measuring light to get mass isn't the most favorable. Gravitational lensing seems to be the best method. So I must ask, have you looked into there being a dark matter curve for a galaxy we have calculated the mass through gravitational lensing? If so then how would they not have simply gone "uh guys this mass is weird from the observations, the middle is way more than it seems" and thus forming new ideas about your time dilation hypothesis. 2. Time dilation barely matters, as it'll be very small. GM/Rc^2 shows just how massive that galactic center has to be to even get near time dilation you're claiming. I'm talking egregious amounts of mass for that time dilation factor to take place to the point it explains away dark matter. Also why would this even happen? And wouldn't we see the redshifting of light as a result? 3. You don't fully understand time dilation. Time dilation is a result of a change in gravity. You're assuming the center of the galaxy must be so massive (again insanely large) that it's strong enough to cause alterations felt throughout the ENTIRE galaxy and VERY noticeably in the center. Does it exist? Yes. But to such a small extent it's negligible. It's not some linear thing that neatly ends at the tips of the arms and causes the galaxy to rotate uniformly, it is a negligible thing to an observer on Earth.
I was so happy when understand fourier analysis as analog of linear combination in vector space but for functions before it actually was compared in a textbook long time ago.
Audio was loud enough, but I think your audio is occasionally peaking, (also called clipping) which gives you static and noise. On any volume monitor this is represented when the bars go into red. There's a lot of filters and techniques to deal with that depending on what software you use to edit.
Yes, good observation. (as a semi-pro / hobbiest mix engineer) Software can certainly help but it depends where the clipping is happening in the processing chain. If the mic pre-amp is just too hot, the recorded audio is forever clipped. Software can only smooth out the harshness but it will still be a lost of dynamics and fidelity. If the mic is hooked up directly to the recording software via a built-in pre-gain or on a mobile phone with the direct mic, then a software setting shoudl be able to prevent the clipping, as already ironically mentioned, a DSP probably doing some FFTs to predict a peak as soon as it’s about to happen and auto-duck the analog gain into the DAC. Finally, you can also just use more headroom if using an outboard mixer or some software with a fixed gain level if you don’t want to be monitoring while recording, and then later use a software compressorlimiter combination to reboost and normalise the volume. This will also boost the now lowered noise floor though, and her room already sounds pretty echoey so I wouldn’t recommend relying on too much software gain later. -12db tops I would guess. Always leave -3db headroom on the final product. RU-vid will re-compress the dynamics a bit anyway as will most operating systems on playback from mobile video / yt. tldr; lower your gain a bit on your mic settings or hardware mixer pre-gain use a software limiter/compressor on the exported audio after editing leave ~ -3b to -1.5db headroom on master stereo output limiter. (sometimes this is a setting while exporting the video in the audio transcoding section) possible get closer to the mic to reduce need for gain which willl amplify the room echos and A/C noise etc.
I think there is an issue with people thinking that the term dark matter is the name given to the phenomenon. It is simply a place holder term that stands for "Dark" - doesn't interact with baryonic matter and "Matter" - they believe it to have mass. The same goes for dark energy, "Dark" - doesn't interact with baryonic matter and "Energy" - believed to have no mass. So the terms basically mean "who knows with mass" and "who knows without mass"
Prefacing this with: I have a bachelor's in astrophysics. Most of my family and friends aren't scientists, so I get asked to explain a lot of science questions. When I try to explain dark matter to people, I usually say something like: "We know how a galaxy (for example) should look/behave based on our current understanding of physics. When we take measurements of a galaxy, we see something different. The galaxy behaves the way it would if there was extra matter (mass); we can do the calculations again with extra matter and show the results match what we measured. We refer to the discrepancy as 'dark matter.' 'Dark' because we don't 'see' the material like we would regular objects; and 'matter', because it has a gravitational affect on the surroundings in a way similar to regular matter. We aren't necessarily saying 'it is a new exotic material', though it very well could be; the name is more of a descriptor there's something that acts like 'matter' but that doesn't give off light (sometimes I explain ElectroMagnetic Radiation), so this matter is 'dark'." Which is basically what you said throughout the video. :D
This a preposterous way of adjusting reality to ( a completely flawed) theory. This is scandalous and a sign of the sad corruption of the science of physics. But: egos, pride, missing theoretical alternative, ‚back to aquare one‘ - horror, really. Therefore we will soon see the „detection“ of Dark Matter ( the fraudulent excuse) and a little later the „detection“ of „Gravitons“. You know why and I spare the effort here to explain it.
So dark matter is a place holder till we figure out what the hell is causing the mass discrepancy, yes? Also the assumption that the same physics laws apply in every part of the universe (not including the event horizon stuff) it is just an extrapolation of the geocentric philosophy that plagued us painfully for a long time. Unless we go and actually measure inside say m31 we won’t really be able to confirm our assumptions. I am not trolling. Just a curious nobody.
@@GiriGagan Correct. In fact, the only way scientists can infer the presence of dark matter is via its gravitational influence which literally holds together most galaxies, preventing their constituent stars from flying apart as they spin. No dark matter particles have currently been directly detected, but the physical observations we make are real. It is possible dark matter is something else, like multiple states of unknown matter of forces caused by unknown phenomena. Most believe that because dark matter ask so much like normal matter and not like anything else in the universe, that its even less likely its something else.
@@GiriGagan no. "Dark matter" is a term astrophysicists use to refer to a collection of observations that share one thing in common: they all deviate from what we expect to see in a way that looks like there's extra matter that doesn't interact with light. They're not referring to an explanation of those observations. They're not saying the deviations ARE caused by excess matter that doesn't interact with light. It's just a sort-of misleading *short-hand* for the collection of observations themselves. Those observations definitely exist.
I love the way you explain things. Tv talks about dark matter like it's this mysterious, invisible stuff, and you do swiftly demistified it. I love this. And the actual science is so much more mind blowing and cool than mystifying it.
My dad's position on dark matter -- and he was very much an amateur science appreciator, a category of person you've mentioned in other videos -- was always that it seems like a systemic error to have to invent a whole category of matter you can't directly observe in explain a bunch of measurement discrepancies, but that was in the 80s and 90s before a lot of the measurements you've shown off here were made. I think you've firmly moved me from there into "Okay, it's real and it's something, even if we don't know what."
Same, I was unconvinced, then it all added up. There are 2 rooms in a house we can see, but looking at math and measurements, we know there's like 40. No idea what's in them, what kind of "rooms" they are, or what their dimensions are, if they have doors or windows, any furniture, but we can concretely measure that there SHOULD be about 40.
@@cookechris28 It's like the universe is committing a gravitational/mass tax evasion. It reports X, then we look at it's prior history and current spending and we find it should be at least 10X.
This might help: dark matter is not a category of matter. She kinda zoomed by it, but didn't really explain what it meant: we *don't know* what "dark matter" is. The reason it's called dark matter is because it's the *cosmological definition* of matter. It's not a new particle. It's cosmological weirdness that we've observed. There's a reason it shows up on the pie chart next to "matter" and "dark energy". "Dark matter is a particle" is a hypothesis. It's the one you think you're hearing when scientists say "dark matter", because you think matter must be made of particles. But we have not observed particles. There is no evidence for particles yet. It is entirely possible that it is particles, but I don't swing that way. I'm not sure we even have a prediction yet. "Dark matter is a consequence of our equations being incomplete" is another hypothesis, which is the one I'm partial to. This one is basically that general relativity isn't perfect and it's missing some piece that we haven't found yet. You know, like how Einstein basically said Newton's laws of motion were incomplete. This is googleable as "MOND" which stands for Modified Newtonian dynamics. The problem with this one is that no one's come up with better equations yet. Those aren't the only two hypotheses, but they're the biggest ones, and there are lots of internal variations (since obviously, the simple version of both has yet to be confirmed). Also note that I'm not an expert in this subject; I just watch a bunch of science RU-vids.
But I will now walk around confidently telling people that dark matter is not a theory but a set of observations, but not to ask me about dark energy because I don't want to get into it.
I keep waiting for the news that someone has explained dark matter in a way that makes it our century's "luminiferous aether." The people who constructed the luminiferous aether concept weren't idiots or liars, either; they were people trying to make sense of the observations at hand. People like Lorentz, Fitzgerald, and Poincaré developed concepts that were eventually incorporated into special relativity because they explained the observations. At some point, someone will come up with a theory explaining dark matter observations, and then 100 years from now, folks will be snickering at dark matter the way people now snicker at the luminiferous aether. (Or not; this analogy could be completely wrong.) In any case, thank you for giving us a clearer way of thinking about the problem.
I love your crackpot compass and your genuine appreciation of the amateur science quadrant! A rare occurrence of YT's algorithm suggesting an actual informative video, produced by a knowledgeable, competent, and kind individual 😊
Thank you for this!! To distill a lot, I feel... better? Like, i already feel better having watched so far (I haven't finished the runtime yet), so, thank you.
Depending on what you used to edit videos, there will be tools within the software to make audio sound acceptable. Right now, the audio is clipping. You don't want to increase overall gain, because that means the peaks cross the threhold of Max output for a device (0dB) and distorts into a noise. Instead you want to 'compress' the sound signal into a narrow-er range of amplitudes. E.g. in Adobe Premier, there is an effect called Multi-band Compressor in the audio effects section. There are a number of presets once you open up the options of this effect, you can try them out to see which sounds best. But it does send you down a black hole of audio engineering stuff, so be forewarned.
Using a compressor could cause distortion in the audio (depending how how much gain reduction you put in it). I think a better method for clearer audio is record the audio at a lower level so that there is no clipping on the input and you still have some headroom to raise the level while keeping the clarity.
@@Bamdd5 the recording level is usually automatic on devices, e.g. iphone. So setting a lower level is either not possible or not a good idea. The automatic gain control is fine while recording. She specifically mentions that she increased the volume in post, so a compressor is the best approach. It gets you most of the way there, just chaining it in series after a noise gate and/or noise removal and limiting the compressor output to peak at -6dB is what will deliver the best output.
@@XxyGoddam it depends on which one you mean. Nvidia broadcast does a good job at removing noise but it makes audio sound like a zoom call. Adobe Podcast does the best job at taking a recording and making it sound like studio output, but it does the same stuff I just described above. I think it's basically running Adobe audition on the back end and the AI part is what tunes the effects instead of working directly on the audio, based on the output I got putting an audio file through both. I don't know of any other notable AI audio clean up tools.
I really enjoy the conversational way you teach. It feels like I'm sitting with someone who learned something really cool, researched it, internalized it, and is sharing that passion and it makes me personally excited about it. I also really enjoy physics and science more broadly.
So to give an analogy, Dark Matter is sorta like how in the 1400s people around the world were perfectly aware of roughly how big the Earth was because they could observe it's curvature and make calculations based on that, but they didn't know what was on the parts they had yet to see themselves, they just knew something must be there.
Dark matter is not an observation. We never saw it. We only saw what we think the effects of it is, but it might be something totally different. A parallel universe, for instance.
Dark matter is simply the name for the observations of the universe. You are probably confused by the name "dark matter" and are under the impression that "dark matter" is simply a type of matter we cannot see or measure or that does not interact with regular matter. It is not. Dark matter is the name for our observations of the universe which show something affecting the universe which we can describe but not yet explain.
as an undergrad studying physics/astronomy i love how these videos combine great educational content with a fun conversational style that feels like a friend telling you all about something they're excited about. i'd also never heard a good explanation of the WMAP plot before, so thank you for that! also, thank you for introducing me to my new favourite song, the dark matter rap. P.S. the sound on this video sounded very good to me, definitely louder than before.
This channel is incredibly great to me cause it's an entirely different field than what I'm studying so it gives me the feeling of taking a break for some entertainment, but it's also cool science stuffs and I love science and science drama has a very special place in my heart! Also as a fresh student of cognitive science it's very interesting to see the differences and the surprising overlaps between the fields. Thanks, much love from Poland
@@gabor6259 it is an interdisciplinary science that takes from neuroscience, philosophy, linguistics, psychology and other disciplines. It explores all aspects of cognition basically. There are many different directions it can go, so like for example many people are into AI and neural networks and stuff, and others take up evolutionary psychology and go from there, and so on. I'm personally fascinated by the direction of "embodied mind", which explores the connection between the physical and mental, how the body you inhabit inherently shapes every aspect of your experience, how your physical reality determines your mental reality. But I'm not advanced enough to specialize yet, I'm only in the first year of university. I hope this made sense, I like to think of myself as pretty fluent but still english is not my first language
@@gabor6259 well... It's very complicated. Mind you, this is just my opinion, so don't take it for facts. Short answer: no, I don't think so. Long answer: mental health of a person depends on countless factors, and while I can think of a few that would be positively affected by attractiveness, they drown in others that aren't. Pretty priviledge is a very real thing, it affects your social enviroment, but so do your hygiene, education, social skills, age, race, gender, social status, place of living, and so so many other things. Attractiveness is a big factor in finding a partner, but also far from the only one. Aside from that it can play a role in your self esteem, but just because you're attractive for other people doesn't mean that you'll perceive yourself that way, and if you have issues with body image often no amount of compliments will change your perception. Attractiveness doesn't protect you from genetic mental conditions, trauma, poverty, discrimination, abuse, malnourishment, disability, it can even attract some of these things! Sometimes it can get you extra help but sometimes it prevents you from getting any. It gives with one hand and takes with the other. And there are of course trends, but beauty is so so so subjective. I have met so many people who would be considered very stereotypically pretty and suffered greatly. I have met so many people who would be considered stereotypically ugly but were doing great. Also, suffering is very hard to compare and we may never know the true extent of any other than ours, but we tend to downplay the suffering of people who we think "have it better", forgetting that they have a different frame of reference. Something trivial to us may be unbearable for them, and vice versa. So, after that stupidly long tangent, still no but it's complicated :)
Maybe you already know this, but think of it as matter that only interacts gravitationally. Or at least that's the only way in which it has been detected. If, as an extreme and non-realistic example, the Moon was made of dark matter, we wouldn't be able to see it, but we would know it's there because of the tides.
Also been binging your videos. I'm one of those left for industry right after undergrad physicists - but after finding your channel i've been inspired to crack open some of my old textbooks and engage with some of the math and theory again which I've really enjoyed. Glad i stumbled across you!
Thank you very much for clarifying that you don't think of amateurs as crackpots. I'm autistic and have a passion (many say an obsession) for cosmology and astrophysics stretching back over 25 years. That said, I have issues which make the math for those difficult to do for myself (even tho I can read and understand the math just fine). Think of it like being able to understand more Spanish than you are able to speak. Expressing my ideas and thoughts in terms of the math has always been a massive challenge, but all my thoughts and ideas are based on observations, experimental data (of myself and many , many others), and combing thru the data. I was at first a bit frustrated that it seemed like you were saying (in a previous video) that if you weren't professionally active and recognized in the field, or have a degree in that field (I have multiple degrees, just not in cosmology or astrophysics), and I couldn't express thoughts in math (hell, I often have difficulty expressing my thoughts in English; my native language) then I was a crackpot. So again, thank you for showing that there are other categories. Also, I agree with your categories. Crackpots make me shake my head and go find kitty and puppy videos, while grifters infuriate me. Anyway, thanks again, and I look forward to all your videos.
FYI there are many people at NASA who fall on the autism spectrum that fulfill important meaningful jobs and no one treats them as less-than. Rather they are valued for the talents they bring to the table and excel at (just like everyone else). I had a partner for years working on various modeling and computer server issues who not only was diagnosed with autism but paranoid schizophrenia and other things. He liked to be called Shteve (for SSH + Steven) and seemingly effortlessly coded complex interrelated hardware and thrived being a part of the team as the feeling of belonging is important to everyone. Non-discrimination along common social lines is one of the amazing things about the science community. Besides, to most of the "outside world" we all seem autistic or something "other".
I thought the repetition was necessary and effective. As a nearly innumerate ex-English major, I had early on formed the idea that "dark matter" was something that existed in, or was predicted by, some kind of cosmological theory and that wee couldn't find it in our mundane observable universe. Instead it's what she said. Repeatedly.
This is the most informative dark matter video I have seen. I had only heard the "velocity" observations before. That galaxy cluster collision is my favorite one. Congrats on 50k! I love the passion and humor you put in your videos.
Hello! RU-vid recommended me your video about “fake data, a scary science story” and many videos later here I am, and I loved them all. You’re doing an amazing job and you’re a great public speaker! It’s like I’m in a rollercoaster of emotions when you’re talking about physic and academia. And although it seems that your subjects are often motivated by some kind of animosity (not sure if it’s the right word, I’m pretty dumb with words, also I’m french. I might rephrase it with “you’re doing commentary about science drama”) but there’s also some real kindness and warmth and passion when you’re talking, I’m having the best time watching your videos, I feel both more humble and more educated after each one of them, and even the basic stuff is refreshing to hear. Thank you! Amazing! I’m at a loss for adjectives!
I learned so much from this video and it changed my "isn't that just another way of saying our current theories are incomplete" to a genuine understanding of this topic. And it was fun to feel smart because I've taken all the undergrad classes and know all the math you did and could follow along with everything. You do such a good job of explaining things while being entertaining/soothing to watch and listen to. You're like a physics Jenny Nickolson ; )
your videos have quickly become somewhat of a personal favourite of mine. The way you tell storys and write and structure this type of video is wonderfull and incredibly entertaining to me. Thank you so much!
The sound level is loud enough, and in fact I think I hear it clipping (spiking into the red and distorting). I can also hear the room ringing. I think the best idea is to use a dedicated mic placed close to you or clipped onto you. This gets rid of the room ring and tends to even out the peaks and troughs in amplitude. If it doesn't do enough of the latter, you can apply some compression to the channel in your recording software. Please ignore if you've solved all this since making this video. 😊
My uncle has an incredible large knowledge of plants and biology of Costa Rica. I have always have the feeling -as a physicist- that he is very “scientific” but in “handcrafted way”. Now I have a term for him. He is an amateur biologist. I love his retirement farm… is so full of trees, fruits and veggies all working together in such a beautiful way. He worked all his life in construction btw.
Maybe amateur botanist? Either way, l love the idea of a retirement farm. I work in horticulture and that's my dream as well! Thanks for sharing your story.
omg ive been excited to hear you talk in depth about topics closely related to your field of study!!! thank you for this awesome content, it sparked an interest in physics for me so i've just been studying calculus and taking notes on old leonard susskind lectures during my free time lol, I would have never guessed it actually would be as satisfying and beautiful to learn about as mathematicians and scientists say it is!
Hey! I am a relatively new fan of your channel. I really enjoy listening to science coming from you! However, I noticed in this video in particular that your microphone was clipping. Clipping means that the audio levels of your signal were maxing out, and because nowadays we use digital software to process audio, this means that if the audio levels max out you get these really egregious and unwanted distortions. Probably a lot of people don't notice these clippings. It really depends on the system through which you are listening to the video, but it also really related to experience in being "tuned" to look out for this kind of unwanted noises. Everybody can hear them, but not everybody pays attention to them. The solution to this is to set up your microphone's gain so that it never reaches the top on the audio level indicator. And then on post-production you can raise the volume of the recording if you feel it is too quiet. Raising the volume can also lead to clipping, but if the clipping was already there in the original recording because the gain was too high, there is no simple way to remove them. Anyways, just as a heads up because I really couldn't keep listening to the video because of this clippings. That might sound a little extreme, but I was listening to you through my high-end headphones, and after years of music production I cannot really ignore these sounds and it makes it really uncomfortable for me. Anyways, love your videos!
I love these conversational style science topic videos, it feels a bit like a one-on-one tutoring session and I'm learning a lot about astrophysics and cosmology from you. The dark matter rap was a lot of fun too! I'm tempted to email Dr. Weinberg and say nice things to him as well :)
The properties of Dark Matter sound like Dineutronium. That is, two neutrons bound together by electron exchange between the two of them. It would be invisible, it would pass through regular matter, it would have a mass of ~ 2 Atomic Units and it wouldn't even react with nuclei like individual neutrons do. Experimentally one could try to find Dineutronium by cooling free neutrons down and trying to detect missing neutrons, while measuring the neutron decays.
11:35 "The new existential dread just dropped" Not much to say, just enjoyed that quote. In fact, I kinda love how sometimes it feels like it's from like 10 years ago and yet never really date it. Great stuff, worth a sub even. 👍🏾
I am LOVING this channel! I have a little bit of a background in Engineering, but my degrees are in Political Science. But I find Physics and science fascinating. I’ve actually started taking a math class with a tutor to better understand and maybe one day get to do research. But this channel has helped a LOT!!! Thank you so much!!!
An issue I usually come across (I'm an evo-ecologist/molecular ecologist/microbial ecologist) when it pertains to what is or isn't a theory usually has to do with the very definition of theory versus hypothesis.
Dark matter is a thing we observe. The theories of dark matter attempt an explanation. Is it particles? Dark photons? Modified gravity? 1200 other ideas in papers you can find on the arXiv? Who knows. Any successful theory of dark matter needs to explain the observations in this video.
@@acollierastro Thank you for that explanation. I am still wondering though if the ideas proposed to explain dark matter are theories before becoming established science or is it the case that theories are by definition established science. In other words if I am Darwin just setting out on the Beagle and I make some observations and then come up a with possible explanation, namely evolution by natural selection, yet there is not enough evidence to correctly claim it as a fact. Is it a theory or just an idea which when proven becomes a theory. So when the "reverend" says to Darwin "no, God did it by waving his wand", is that the God theory? Or at this point (before the evidence) is it that there are yet no ideas worthy of being called a theory. Sorry to belabor this, but I would say neither version of "theory" makes dark matter a theory, nevertheless they are 2 different uses of the word. Which of these definitions is the standard in science. Like you it appears I can't be short. Sorry, (and thank you )
The word you're looking for is "hypothesis." Hypotheses that withstand rigorous investigation without being disproven are elevated theory status. Evolution started as a hypothesis and through ensuing rigorous investigation/refinement was elevated to theory status. Religion/belief in gods would be essentially hypotheses that are mostly untestable (e.g., rely on psuedo-science or "faith"). The methods to observe dark matter would be what you need to investigate further to ascertain whether they are valid techniques. Then of course, other hypotheses to explain what dark matter is and why it can't be detected via most normal means.
@@ianhiggs I mostly agree with you. I didn't want to use hypothesis because I was concerned it would add further confusion. I'm curious though what Dr. Collier thinks.
Would it be correct to say "dark matter is a question/problem"? Similar to the ultraviolet catastrophe: We know that our current methods don't explain the observations, so we need a new theory.
My son-in-law just got his PhD in experimental Physics. So seriously proud of him. I love him to death. I appreciate what you guys go through to get a PhD. Not EASY. I'm glad you pointed that out. I never saw it as a theory and was surprised that some come to that conclusion . More of a placeholder for something that can't be explained (yet). Same with Dark Energy. I would LOVE to have one of those mysteries solved in my lifetime. Who knows.
@@SuliXbr It's a common misunderstanding that a 'theory' is a guess. Don't feel bad about that one. A scientific theory can take a lifetime to make. It's a model for how a system works and requires data from several fields of science, a ton of research and proper mathematics (in some cases) to calculate predictions). A well tested scientific theory is the highest achievement that a scientist can acquire. They are rare to have and rare to have fully accepted. Some examples are General relativity (Einstein) and Quantum Mechanics (well, a ton of people were involved in that one). I should add that dark matter and energy require answers of course but we're not even close to scientific theories on either of them. Could be a lifetime to get one - or never. Who knows.
Hi Angela - I love all your videos -- I'm a mathematician with an interest in physics, but I have never formally studied astronomy. Your videos are very helpful for me. And I chuckled about Fourier analysis for kids because I just recently had to explain it to a kid and I think you did a good job. Seeing lots of papers by people who SHOULD know better seem to not understand that we can know what frequencies occur but not when OR when they occur but not the frequency. (Schrodinger). You did a great job communicating that key part.
There are multiple reasons that comments likely aren’t great for gauging the view of all viewers. Didn’t watch whole video, if they did it might have been after leaving the comment, and people who got it being less likely to comment. The like to dislike ratio might be better. People probably won’t like if they didn’t get it, and probably won’t dislike if they did.
This answered pretty much everything I was wondering about dark matter. I feel like your videos are great for people with vague physics knowledge but who don't get satiated by pop science media - for context, I have a maths background but my interest in physics is just curiosity
While this video didn't address anything I was wondering about dark matter, I'm also in that category of people, and completely agree. It's not just pop-sci media - a lot of science communicators themselves will talk down to their audience and oversimplify things for the sake of explanation, so much so that their crude analogies can leave the audience further from the truth. Dr Collier's videos are like a breath of fresh air by comparison, it makes me happy to see her subscriber count growing so quickly.
I really love that channels like yours exist. I always thought I was stupid growing up because I just never seemed to enjoy leaning back in middle and high school.. turns out I can learn and absorb new information exponentially faster and retain that info when I'm in a 1 on 1 setting (or watching a great informative YT video or documentary). I absolutely love learning anything about Cosmology, Astrophysics, or just Physics in general and I love how many amazing educational content creators there are on the platform. I first fell down the rabbit hole a few years ago when I watched a video of someone trying to explain how we can "attempt" to try and visualize what 4 Dimensional objects would look like, and the creator made the reference of how our 3D shapes would look to a 2D being. It was such a random video for me to watch but it was like putting a spark in a can of gasoline. I think what messed with my brain the most was when the creator showed the 3 Dimensional representation of a Klein bottle and explaining how if we were looking at it in 4D space it wouldn't intersect (Brain go boom lol). I've been absorbing all I could find since than. It really broke my brain when reading about Superposition and the way the Electrons behave from such great distances. Than I broke my brain again leaning about the Double Slit experiment which made me fall into the Simulation theory rabbit hole haha. I just wish my teachers growing up were more passionate about the subject they are teaching, if they had 10% of the passion that creators like you and others like Veritasium, Physics Girl, or even Vsauce have I think a lot more students would put more effort in. Just found your channel today btw, so I'm really happy to add another thought provoking creator to my list! 😊😊
