@@Underwhelmed I guess rationality is not exclusive to science channel comment sections. Yeah I prefer Matt far more. He is like the Bob Ross of astrophysics.
Brainjock I disagree, but guess what, opinions are allowed to exist here on Earth. You can’t rationalize your opinion with logic by saying there were more views with the last guy, because it doesn’t make up the whole picture. Who knows how many external factors related to just Google and their RU-vid algorithms _alone_ created? I certainly don’t, and neither do you, but it doesn’t actually matter, because opinions are still opinions. I enjoyed Gabe hosting the show a lot, but Matt and his accent and mannerisms just make the show more enjoyable for me personally. There’s no science driving that opinion, it’s just personal preference for each one of us.
Matt thank you and all the people in PBS for doing these videos. I am engineering student and when i started watching ur videos 2 years ago i was literally brain dead about astronomy and for so long i felt like it was torture on my brain watchin this stuff( sometimes i still do little bit :D), but today i feel like i now a lot and every time when i watch at the night sky and think about universe i feel incredibly happy to be able to understand so much and you deserve a lot of credit for this. Thank you again and please continue doing this. Much love from Zagreb, Croatia ;)
I hope you get out onto a dark, tall mountain and then really think about it. I visited Haleakala recently and there's something hard to explain about seeing the incredible number of stars, then looking through some good binoculars and seeing...just way more stars. And sometimes satellites and other things if you're lucky. It's one thing to hear about 100 million stars in the galaxy and another to actually start seeing it.
Exactly, I'm also an engineering student, 2 years before I accidently searched about black holes (although I was used to these kind of stuffs) and this channel popped, at that time his language was so difficult for me to catch, but now I think I am pretty much familiar with that 😊
Feel the same way, it's just nice to be able to understand the universe we inhabit at a more fundamental level. I find myself thinking about things like physics and relative frames of reference when I'm driving my truck and other day to day activities. It's a nice way to go through life.
If you could just keep uploading every Monday after lunch, and every day afterwards until the end of the time, that would be splendid. There's always time for space.
Fascinating astrophysics. Seems like a negative feedback interaction between galaxies and their central black holes. More gas -> more active black hole -> more outward radiation and wind -> less gas suitable for star formation or feeding of black hole. Like a thermostat at the center of each galaxy.
Wow the first thing I noticed is how nice the speakers outfit looks especially on this background compared to most of these videos. What a great view to learn about black holes 😊
Damn, I love this channel. Matt is such a wonderful presenter - the writing team, graphics dept. editors and in fact, everyone involved at all, right down to the people that vacuum the stdio afterwards all deserve big hugs. May I propose an idea one episode? Not very interesting, but rather essential and underpinning every video that either has or will ever be produced: That is - "Introduction to equations.." It's all well and good showing off the effect of mathematical predictions, the images from giant telescopes etc. But what would be wonderful is showing where the equations can then point you towards an idea that falls out of the equation you design and that can make new predictions. What do the Greek letters mean - what do Greek physicists use in their equations? How do the more complicated ones work? How were they "discovered", "uncovered" or "invented"? (An altogether other debate entirely!) Are equations 'perfect' - i.e. can E=MC2 ever be more accurate, or does it describe the conversion process from energy to matter perfectly? This suggests that equations simply 'exist' just waiting to be discovered. I'd love Maxwell's equations broken down into their component parts and how the symbols relate to real variables and interact between themselves to describe an entire phenomenon.. (then go on to say who the combination of equations describes more than the sum of its parts.
Try Crashcourse or It's Ok To Be Smart, theyre both PBS sponsored channels and often cross. Personally I enjoy the University of Nottingham's channels like Sixty Symbols or Numberphile. This is *PBS Spacetime*
That's all well and good, but you basically just described physics 101, 102 and 103. Those were some of my favorite college courses. If I didn't get accepted into engineering, I was going to go into theoretical physics. I still watch every video and read every article I can find on anything quantum/standard model-y. PS/EDIT: This channel has already gone into massive detail on many (if not most) of the subjects and topics you described; they just don't go into the math-heavy side of things, there are other resources for that. That being said, if they started a new series focused on the nitty gritty, the history, the ins and outs and everything else, starting from the very beginning, "what even _is_ a number?" and going on from there, I think that would be fantastic.
Dammit, I've got an exam on extragalactic astronomy tomorrow and I was trying to procastinate by watching youtube video's, but you've actually just comprimed half of my textbook into a single episode here
After each video I spend several minutes deciding on a response. I take my time to ensure that it's exceptional and eloquent. Gleaming with pride I think to myself, "This is the one. Surely I'll be noticed." After posting I scroll to find a seemingly infinite amount of responses mocking me, with patronising, condescendance, via their author's vastly, superior intellect. I scroll back to my orginal response of, "Space is guud" and hit, "Edit/Delete." Damn you Mittens...
Hands down the best show in all of spacetime. I recommended this channel to a girl I saw everyday at the library. She was minoring in Astrophysics. I fell in love with her the instant I saw her holding a book titled "Advance Stellar Astrophysics". That was the second time I talled to her. But I did not have the guts to follow up w her. So, Sabrina. If you're reading this, you're welcome! Hope you have a wonderful life ahead of you.
@ｋｙｓ Yeah, and I understand all that. I never said you were wrong, but I can certainly understand another human's desire to go out and see more of our universe. I think we all, in this comment section and others, have that desire (ofc, *sigh* barring the flat earthers and whatnot...) I feel that desire too, made worse by the fact we would be incredibly lucky to even experience any type of space travel in our lifetime. I reasoned this was more about being a human, than anything else. If I'm wrong original poster can correct me. *shrug* It's just about being human.
@ｋｙｓ Ahhhh, absolutely fantastic point. We see a lot of news and companies making claims of passing significant milestones to "AI", but to me (software engineer) making a claim of "we are close to it!!" or other... Isn't a definition computer scientists can capably assign: After all, we're not experts in what would constitute an "intelligence", right? Or "life"? Or something in between? To me, it'd be up to Philsophers and Biologists and Neuroscientists and the like to approve a definition of something that truly operates within these parameters, like humans would/do. We have software that, if placed in specific predefined environments, can exercise a lot of the facets of a "rational mind" (called Business Intelligence)... But that doesn't include the capability to "poke" unfamiliar environments, draw conclusions based on previous experiences and try to infer how to react appropriately in completely new surroundings. Our best efforts are still to develop reactionary systems, based on them encountering input of some sort. If that specific input doesn't register... Its difficult to truly code something like "instinct"/intuition. Its difficult to define motivation passed "continue securing the ability to function indefinitely", because surely the ability to survive is a necessary qualification of intelligence, but survival isn't the only concern of something that's alive. Living beyond survival isn't even a uniquely-human aspect. This is all just my point of view, and surely impressive strives have been taken by other engineers/developers... But we shouldn't allow hubris to be our qualification for letting guys like me define what relationship things like "intelligence" and "life" have in common. Again, just my opinion, I think there has to be biological components to something advanced like we've discussed. Technology is... Passive/reactionary, through no fault of it's own. You could say humans are as well and I'd agree to a certain point, but again we have motivations beyond those simply transcribed by genetics over time. Those "non-primary" motivations have allowed humans to accomplish incredible things. Like Wilbur and Orville Wright - if they just stuck to everyday business operations... Y'know? There's something special about a human mind. Operating beyond survival functions into what we may call "passion" is unique to us. Those areas chosen to focus our passion isn't random selection, there's some other process that lights a fire in our heart to pursue said passion. Something not able to be easily defined through the language I'm speaking to you now, much less expressed in a computer language. It's extremely difficult to create something you don't understand, and unless stumbled upon by chance (rarely), complex innovations are often impossible.
The fact that star formation is slowed down, means that the lifetime of the universe increases. Black Holes save the universe! You could print that on a Tshirt
Well, they are the Universal Quantum Computers garbage collectors, they consume and recycle the garbage into hawking energy and store for later, while pushing away the good-stuff™. Ain't nature brilliant?
I don't see how the slowing rate of star formation can contribute to the "health" of the universe...spacetime acceleration is costantly increasing, creating more space every second, separating galaxies from one another. Afaik, the lifespan of the universe is shortening, or it will just go on forever in complete darkness. Unless (I guess), you consider your future local cluster of remaining galaxies, THE universe. I'm open to suggestions, ofc.
@@JohnDoe-dj3lw I think he meant that by slowing/stopping star formation, the whole galaxy is functionally put on pause (the "Holiopause"?) in its evolution until it cools down enough. Eventually, all that orbiting galactic gas will start to coalesce again in a second age of star formation.
I’ve learned more from this channel than in all the physics lectures I attended in college. It’s wonderful that this is info freely available to anyone curious enough to explore. What a time to be alive!
You monster! You had this beautiful simulation of galaxies colliding and you keep talking over it making me unable to focus on either of two amazing things.
Thanks for another great video! For some strange reason, this episode made me picture a scene from Star Wars. They're on the medical frigate, & Luke Skywalker has just gotten his cyborg hand. They stand looking out a window onto a stunning view of their galaxy, from several galaxy-widths away. What an amazing sight! I fervently hope that humanity will one day be able to have such a view of our own galaxy - & others - if it so wishes! Anyway, I'm grateful for this series (or channel), along with a VERY short list of others, for keeping my mind & my imagination stimulated. I suffer from depression & anxiety (I'm having a bit of a bout right now, actually), & I find that - more than almost anything else - the sense of wonder & amazement I get from learning about & contemplating this incredible universe keeps me going. It not only takes my mind off my mind (so to speak), but fills me with a feeling I'm at a loss to even explain. I must admit, I'm at least as puzzled as any astronomer by the black hole / galaxy correlation! It raises all sorts of questions. If dark matter reacts gravitationally, how'd it avoid falling into the centers of galaxies? Why does it "hang out" in the boonies of galaxies? And how does that affect the formation & evolution of them? Did the regular matter that got pulled in fall right past the dark matter to the center? How? Why? What effect did the central black holes have on that? Or vice versa?!? Maybe a better name for dark matter would be "shepherd matter"?!? Would ALL galaxies prefer to be red AND dead? :O Do black holes affect ALL the stars in a galaxy by a sort of chain reaction; meaning, do they affect the stars immediately around them, which then affect the next layer out, & so on & so on? Does the fact that massive (&/or super-massive!) black holes existed early on in the universe change our perception (that is, our estimate) of how much material (matter, dark matter, etc.) existed in the beginning? Well, as you can see, I've got a lot of stuff to think about (& that's just in cosmology!) Very exciting! Thanks again. tavi.
The best channel on yt!!!!! Great work guys!! I am glad to see that you have listened to people asking for little slower talking , about science stuff . It is superb now 😊😊😊 Thank you!!!!!
Guys you all should try 'videogame' Space Engine. It's an absolute astonishing map of the almost whole universe. Ever wanted to land on any planet you know?
Yes, they tend to prefer to be perpendicular to the galaxy (Galaxy on the equator, jets at the poles.), most likely due to how the central hole aligns with the galaxy and how jets are produced. But this still allows them to efficiently dispose of gas. It's not as utterly terrible as a jet into the galaxy's disk would be, but it's not good.
Black hole mergers can dramatically reorient the spin axis of the product black hole. For black holes in old giant ellipticals like M87 there have been so many mergers that the spin axis can have been reoriented frequently in any random direction. Evidence of this is commonly seen in radio observations of kinks within outflowing jets emanating from distant active galaxies. The outflow alignment seen in many disk galaxies has another factor that comes into play: high rates of star-formation in the central regions produce high rates of supernovae that produce super-remnant outflows that are often collimated by the general galactic magnetic field to fountain outward at right angles to the galactic plane, regardless of the orientation of the central black hole's spin axis. This seems to be the case with our own Milky Way.
I was just thinking about the relation between masses of galaxies and black holes in them. And today I found this video, with answers to my questions. Thank you so much!
Hey will you guys do one on this recent Susskind thing about black holes continuing to grow forever on the inside while the outside stays the same size, and how that growth might be related to complexity? Seems super weird and intriguing and right up your alley.
Hey Matt, when you are uploading such fast animations with a lot of things moving, you could cheat out some "continuous resolution" with upscaling the video to 2K/4K resolution. It pains me to see that artifacted render of the universes processes. Just a tip, I'll love the vids anyway!
@@DoctorMoguri nono, you can't do that, youtube re-encodes everything, the only way you can cheat out some extra bitrate if you increase the resolution
*_...actually-we expected "bottom-up" hierarchical coalescence of galaxies long-before "dark matter" became a question-since Hubble expansion of the cosmos removed one factor-of-R from the equation, meaning, galaxies formed when cosmic gas density was enough, and then stopped, as-size, and mass, could-not-overcome space-expansion..._*
I would like to Express my opinion. I watched some of your programmes and found that I do get lost sometimes trying to keeping track. I watched similar programs and found them much easier to grasp. The reason behind that is that you switch lines from one explanation to another, then you go back to the first explanation and so on. It's like trying to explain something in an explanation then going back to the original explanation. Like backward and forward. But you are very knowledgeable
That _Red Dead Redemption_ reference lends an entirely different meaning to Arthur Morgan's theme song: ♪ _Will I stand unshaken_ ♪ _Amidst a clash of worlds?_
I noticed the added background music this time... at first it sent me looking for what browser tab was making noise so i could turn it off... Maybe turn down the ambiance just a little more and turn up Matt. Great video though! Keep it up.
The part about the cats being drawn to humans suffering is 100%. The rest is pretty high lambda too. Keep up the amazing revelations on what is real in this ever expanding, entropy seeking, greater and visible...... spacetime
If I may ask a question that is probably more related to the "no dark matter = proof of dark matter" episode but still relevant to this one. So, on the proof of dark matter episode the evidence discuss was on star clusters that seemed to be held by their own mass. on the other hand, today`s episode approaches the idea of supermassive black holes extending their influence through the whole galaxy. so my question is if the dark matter free clusters that were studied had any evidence of having a black hole in its centers?? PS: love PSB Space Time. Fan since Gabe was the host.
No, they're very dim and sparse so we can't tell what lies at their centers. However other, equally dim clusters are often very high in dark matter and also show no evidence of central holes. As a side note our galaxy is about as massive as Andromeda, with about as much dark matter. But our central black hole is about 1/50th the mass of that in Adromeda, so there seems to be no relation there. And as a final note, this episode was about how the gravity of black holes CAN''T directly affect an entire galaxy, instead its radiation must.
This is gold. Thanks. Galaxy formation and their evolution is/was one of the most puzzling things in cosmology. I was always wondering whether they form from top down or bottom up, glad to have the answer.
I imagine there's probably significant outward momentum from the many supernovae at early galaxy times, the dispersal at the time of black hole formation may be the key factor in their outcomes
I guess galaxies too die if they are killed. I have to wonder though, if for example, two older supermassive galaxies were to collide, what would be the upper limit of their mass? And would their merger promote the formation of newer stars enough to make it look younger (i.e. from redder to bluer)? And has there been any actual observations of this happening? Sorry for list of questions and thanks!
I see these so-called 'dead galaxies' kind of like the hairs on one's head. They still grow, slowly, over a _loooong_ period of time, and will continue to exist without 'decomposing', but at the end of the day are still very much dead of cellular activity. Of course, discounting the _external_ living organisms that thrive and feed _on_ the larger, deceased 'fibres' - eg bacteria (or headlice if you prefer), like breathing, still-very-much-alive stars and (possibly) planetary satellites.
I feel pretty smart after I watch one of these vids. Then I gradually come back to reality and realize how dumb I actually am. My search history is proof of that.
So I had a question. I was told that if you fell into a blackhole (and you were looking out) you'd see essentially all of history flash by you since time and space would be collapsing into the same point as you are. Is this true? Also I was told the larger a blackhole is the longer it would take to be spaghettified - This implies that a very large blackhole would have almost like a goldilock zone where nothing is happening and space and time are acting normal. So with this information I wanted to ask if you had a large enough blackhole (universe scale) could people be totally unaware that they are even ontop of one? Basically could a universe be on the outer layer of a very large blackhole in this sort of goldliocks zone if it was large enough?
If you fell into a black hole, all light from previous events would be ahead of you, and you'd never interact with that light. It's true that supermassive black holes have only moderate tidal forces at their event horizon. But stuff still gets pulled in, and promptly approaches the singularity.
It'd be an odd universe. Everything in it would be in free fall towards the center of that hole, so it wouldn't be expanding (If anything it'd be slowly contracting as everything converged on the central singularity.) In one direction light would be redshifted as the hole pulled it in, and in the other it'd be blueshifted. These phenomena would be very big clues indeed to that universe that it was falling towards so gigantic mass and it wouldn't take them long to finger a black hole as the culprit. Now if the hole were truly massive these effects would be smaller, but it'd need more mass than the entire visible universe we see, far, FAR more. And even then the 'free falling' universe would have some odd properties that would alert its life to something being amiss.
@@garethdean6382 yeah thats what Im getting at. Based on a hypothetical lets say the blackhole is much larger than even the known universe. If given enough distance from the singularity and the event horizon is there a point at which the effects of you falling in wards would be not even noticable or where spacetime itself appears to act "normal" like our universe right now? Sorry if Im not getting this across correctly or it makes very little sense but its always been something Ive thought about when I started looking into blackholes. I just imagine the fact that theres still potentially information within it even after the event horizon and before it reaches the singularity.
No, not like our universe as it appears now. Certainly you could have a STABLE universe, one that lasts billions of years, but it'd have a 'preferred direction', the dimension pointed towards the center of the hole, that was arranged differently, especially if you want that universe to have a 'big bang' of some sort. To get a universe like our you'd need a setup big enough for a 'bubble' to form that was roughly uniform in all directions, which is what we generally see in the sky. It'd be riding a larger 'wave' towards the hole's center, and that hole would need to be vast almost beyond comprehension.
“..and blasting the crap out of the galaxy’s gas.” (6:40) I laughed at that every time I listened to it - an unexpected phrase, to say the least. But seriously, please quantify “the crap”. Love the channel, keep em coming!...
I think what he's saying here is by the time the quasar shuts down, a lot of the gas in the Galaxy has been ejected from the Galaxy by the extreme power of the quasar
@@justinpetersen433 _into the ever expanding void between galaxies
5 лет назад
@@justinpetersen433 No. I am trying to both answer the question and provide some extra information. In context of the video, elliptical galaxies are "dead" for good. Yes, in couple billion years they may see some new stars created, but the universe will be a very different place by then, dominated by the dark force, if I remember the name correctly.
Really insightful video. Last year I attended a small lecture in my university held by a researcher in astrophysics from japan explaining how he led simulations on the relationship between young galaxies and their newborn supermassive black holes but he did not really hint at all this data and these interesting and meaningful conclusions that can be taken, or if he did perhaps I didn't understand. By the way, I love watching these videos at night, the soundtrack is so minimal and quiet, yet so suggestive
Is it possible that the central supermassive black hole's gravitational influence is extended by the phenomenon called "frame dragging"? As I understand it, if the black hole is spinning, then it literally drags the surrounding spacetime with it, like sticking a fork into a plate of spaghetti and twirling it. If you did that just right, then you would form a shape not unlike a spiral galaxy. Over the course of millions or billions of years, could frame dragging influence the shape of the galaxy? Could that also explain "dark matter"? Perhaps it's not an undetectable form of matter that causes the anomalous revolution of stars in a spiral galaxy, but a sort of "chain reaction" deformation of spacetime ultimately caused by the spinning supermassive black hole at its core?
There are a few problems. Frame dragging involves space. When you tug on a piece of spaghetti the force moves in one dimension and is just as strong at the other end. Plus spaghetti cannot pass through itself. Space however is three dimensional, causing effects to drop off with distance, and can do things like compress or curve. So it's more like trying to stir an entire pool of water with a tiny little propeller in the center. The effect is too weak to work on our universe's timescales. Back to spaghetti, if you stick some on a fork then spin that fork rapidly some will fly off, it's not being held to the form enough to stay bound. Galaxies are rotating fast too, but not flying apart. This suggests a sort of binding force holding them DESPITE their fast rotation rather than a fast rotation 'just happening' because of some other effect. Plus hole mass can vary widely, our own galaxy is about as massive as Andromeda, but houses a hole maybe 1/5oth the mass. Yet both our galaxies rotate about the same.
@@garethdean6382 Thank you for the reply. What you said makes sense. I wish I had the education to utilize the high-level mathematics of physics rather than thinking about the universe in terms of mental models and silly analogies. It would certainly make it easier to, say, understand the properties of spacetime and how it behaves in the presence of mass... among many other things, of course. Thanks again!
I wonder if the magnetic field in the galaxy has a correlation between how a galaxy forms, how the galaxy evolves, and how the galaxy stays together. In the way that magnetic fields of stars may interact over great distances because of the galactic magnetic field. This may also explain why an elliptical galaxy has no star formation; because the magnetic field in the galaxy is disrupted so star formations that would follow a galactic magnetic field is both bereft of gas and the energy that a galactic magnetic field would provide. Thanks guys I love the vids please keep up the great work!
