How do we know there's a black hole in every galaxy centre? | History of Supermassive Black Holes

[@conors4430]

I love how you explain how peer reviewed science builds on itself. It’s something so many people don’t get to see the importance of

[@ramchandradey4059]

Without knowledge of indian philosophy in particular and world philosophical thoughts in general neither science nor religion nor any other system of thoughts can wholly comprehend and explain the basic principles of reality as we are yet to conceptualize both the latent and manifest potency of humanity

[@Z-add]

How did einstein came up with general relativity. Whose research did he build on?

[@nnaammuuss]

@@Z-add Well, not a physicist here, but I gather that the constancy of the speed of light in spite of relative motions, as well as some cosmological discrepancies (were known and) were already being discussed which he factored in. To quote concrete pieces of theoretical works, the 4-dimensional Minkowski spacetime was long derived, tensors, tangent-bundles and stuff well studied in mathematics both by algebraists and analysts, and more recent works by Poincaré on topological spaces to help _patching up_ general geometric objects piece by piece through one seamless framework were available to him, and in deed, sources say, motivated him. Not trying to infer that absolutely original research can't be done though. 👍

[@Famous_Mist]

How right you are. Because without it the path was open for flat earthers and other idiots

[@bored78612]

@@ramchandradey4059 People like you are so embarrassing man. Stop tooting your own horn acting like you are super smart when you clearly know nothing.

[@DirtyRobot]

Did not notice any editing. Just sounded like someone talking for 25 minutes about something they were very passionate about. So, 10/10 filming, 10/10 editing, 10/10 concept and execution, 10/10 story/information, 10/10 for the lead demonstrating an awesome way to communicate. 10/10

[@kimghanson]

I thought you were exaggerating but it really is 25 minutes. Seemed like about 7 or 8 minutes. A sign of an outstanding teacher.

[@radioactivet-rex286]

Also 10/10 cuteness

[@DirtyRobot]

@@radioactivet-rex286 Unfortunately I had to unsubscribe due to her BLM advocacy.

[@StanColson]

Theory piled upon theory piled upon made up stuff. If you can't explain stuff, just fabricate (invent) a new thing like Dark Matter, or like Dark Energy, or Darth Vadar, or Dark Light, or Anti Light, or Anti Gravity, or Anti Big Bang. What a bunch of bunk these guys have constructed in order to keep themselves funded by clueless politicians or Anti-politicians (whichever lights your lava light). It is a religion really, but one that is ever changing, evolving, expanding, or anti-expanding ?? Maybe its a 'Dark Religion' ??

[@dbaker3751]

I noticed an edit at the 8:02 mark.

[@Azameanie]

Your histories of astronomy and astrophysics are your most interesting and most important episodes. More than just name dropping, you demonstrate that even the giants of the field, Hubble, Einstein, Hawking, all worked incrementally. They added pieces to a puzzle begun by men and women long before them, and still incomplete. These were always my favorite episodes of Cosmos (both of them). It’s inspirational as hell. 👍👍

[@cowboyfrankspersonalvideos8869]

Great history lesson. Having been born in 1952, I feel privileged to have lived from just after the realization that the Milky Way isn't the entire universe, through the Hubble Deep Field photos, the discovery of supermassive black holes and the discovery of gravitational waves. My biggest cosmological regret is I probably won't live long enough to see what discoveries come from the future LISA program.

[@danielthesantos]

HAH! Well that makes me -18 years older than you!! =D To be honest, I don't understand how they are going to manage that in space (LISA), but I can only imagine the discoveries. Plus I would think they would need some super-computing cluster out there to isolate all of the various signals. I'll have to read up more on it, but I don't know if I'll be around for it either! :) Thanks for sharing your perspective though. I would have been born when you were finishing high school, but it's amazing that it was *so recent* that we didn't know about galaxies yet!

[@walkingwounded3824]

Well, I am a baby, born in 1964. I am glad I'm not here with only "Genius children". This Dr. Becky is really good at explaining things so anybody could follow. Even an old, beat up rocker like me!@@danielthesantos

[@KalRandom]

@@walkingwounded3824 Na I'll be the baby in this chat, 1970. I'm amazed at what has been discovered in my lifetime.

[@walkingwounded3824]

@@KalRandom I see I've been replaced! lol

[@godsownlunatics9650]

tHE ENTIRE uNIVERSE IS NOT THE ENTIRE UNIVERSE. NO ONE KNOWS WHAT'S BEHIND THE SUN LET ALONE 3 SHIFTS OVER SURPRISES ARE INEVITABLE

[@archaurore3323]

I loved how you discussed the discovery of super massive black holes and how you finished with current research (including your own). As a very little girl (age 6) I went through my father's astronomy magazines and I remember very clearly how there was a flurry of articles about quasars and what they could possibly be. I think one of the most outlandish theories was that it was a star cluster or even a galaxy full of neutron stars. This was back farther than I'm willing to admit. It was only around the mid-80s or early 90s that I remember the super massive black hole theory being proposed in the popular Press.

[@PuzzleQodec]

I remember an article I read as a kid that quasar were so bright, they must be white holes. Which was a fun read but I found it hard to believe. My main conclusion was that nobody had a clue so people felt free to speculate away.

[@quietyard8014]

Yeah it seems what we read then was like 10-20 years out of date.

[@calyodelphi124]

I just love the enthusiasm and the energy you have with astronomy and cosmology. You're the kind of scientist we really need in this world.

[@mountdrinan1]

@Carlos Saraiva she is NOT a scientist though. Scientific method cannot be performed in her area. She is what’s known as a pseudoscientist

[@mountdrinan1]

@Carlos Saraiva I never do drugs so no. google “scientific method” . Now tell me how astronomy gets past the first stage of five. Yes. They can observe a phenomenon but I wait with baited breath as to how you think they can proceed through the remaining four 100% required stages. They are the dictionary definition of Pseudoscience....

[@mountdrinan1]

Nah. I know I am clever. My assertion that astronomy is junk science is Sound and unchallenged. Good day

[@bldtv7038]

Carlos Saraiva 3 fallacies in one post. ad hominem , baseless assertion and a hand wave dismal. Do you care to tell me how astronomy follows the scientific method or do you want to hilariously give me more of your fallacy examples. I’m waiting

[@bldtv7038]

Carlos Saraiva , ok with the weakness of that reply are you about to concede or are you going to tell me how astronomy follows the scientific method ? I’m going to hold your toes to the fire until you answer this so no more weasel replies. Answer the question Einstein wannabe

[@brodaclop]

I really appreciate how you managed to put across (despite video being a linear medium) the idea that the path leading to our current understanding isn't so much of a path, but a constantly branching and merging network of discovery, with dead ends, U-turns and sudden leaps of faith that then had to be connected back to the rest.

[@bobcabot]

Congrats: You got the rare talent of explaining (really) complex things in an easy manner! ...cant wait to see you delve deep into the controvertial stuff...

[@Tuning3434]

You know that Dr. Becky is a regular in _60 symbols_ and especially _Deep Sky Videos_ ? I was kinda surprised she had her own channel, but I don't need Brady to enjoy her expositions.

[@bobcabot]

@@Tuning3434 I did not know that! ... she is just brilliant on her own ( better for her talent i guess ) ...

[@danielthesantos]

@@Tuning3434 Brady hurt my feelings when he didn't do a video after the media release of the neutron star merger. I was so excited to see some deep sky videos on it. That was truly a revolutionary moment, the beginning of multi-messenger astronomy. Sorry for my off-topic lament! :)

[@knucklecorn]

Interesting ✔ Good audio ✔ In focus ✔

[@papinkelman7695]

Dr Becky ✔

[@danielthesantos]

LOL! In focus or not, I love them. I just thought the other one was an artistic interpretation? ;)

[@erictaylor5462]

I agree. But the lighting is a bit off. She looks like a Smurf. But who cares about the color of the lighting when her content is so engaging?

[@katchou1337]

xD

[@vencislav_krumov]

Thank you, Dr. Becky for making an entire film on the same subject as my a bit overdue assignment on the History of Astronomy course at my Astronomy master's program.

[@DrBecky]

Vencislav Krumov 😂 you’re welcome - just don’t forget to reference me!

[@Hailfire08]

Hmm, what are the chances, eh?

[@kingWesternTube]

I really enjoyed getting some of the backstory. Please consider doing more videos like this.

[@AlexPronovealexcooper1]

The historical perspective you paint is the best part of your narrative and I notice you do it in many of your videos. That's what differentiates your videos from the others. You have secured that niche. Well done, Dr Becky.

[@Tritium8]

What a fantastic story of science, well put together.

[@Chew1964]

Yep! I added it to my favorites.

[@davidlillo3392]

Your intro statement is exactly why I fallow you. You give the background and take everything full circle until you get to where we are now and what questions we still have. 🥰🥰🥰

[@BIGV1N]

Dr. Becky, you are my favorite astronomer EVER! I get excited whenever I see a new video from you!

[@scottwatrous]

This is the kind of knowledge we need. Love hearing about the evolution of understanding. I would watch a similar episode on our understanding of stars in general. It's crazy how I don't remember our understanding of this being different while growing up in the 90s. I remember drawing black holes on my homework because the quasars are just so cool looking. I just assumed we knew that they were black holes for decades. But turns out it was fresh, and I was just too young to have any other knowledge. Also hearing you were born in the 90s is making me feel old as a late-80s baby. Like, holy cow, people born then already can be doctors of science studying black holes! Also is that your diploma there? It looks so cool.

[@shezcop4987]

Great how you put in the bloopers at the end. Thoroughly enjoyed this. I Subscribed immediately. Don't ever stop.

[@renaudkener4082]

Super massive "THANK YOU" for this video

[@aidanjt]

I see what you did there!

[@Pradipawa]

Hmm.. really massive

[@RalphDratman]

Be careful with that much mass! Safety first.

[@erictaylor5462]

Do you think it's 4 or 5 billion solar masses?

[@grayaj23]

THIS was for me your most fascinating video I've seen yet. Every bit of it was interesting and the history with the names and times was terrific.

[@thomaswolfe9539]

This channel is fantastic. Love that you don't skim over the details, but also focus on the big idea's from each observation / discovery to prevent from going into too much detail. Thank you!

[@noelwade]

Wonderful video! It takes a ton of effort to develop a good explanation on any topic - much less a story told over 100+ years by a variety of contributors. Thanks for putting in all of the effort, and gifting us this great presentation!

[@Flexible_photon]

Very well done. Being 45 I remember reading about "possible" black holes back in the early 80s when I was a kid. I also remember quasars. it's interesting to see how all this fit together because it answered a lot of questions that I've had over the years. Thank you so much for filling in those spaces.

[@Gohka]

Woah, woah. Born in the early 90s? Are you telling me the good Dr. Becky is at least 3 years younger than me yet has all this knowledge, expertise and a real enthusiasm for her work? I now feel like I have achieved so little in my 32 years lol.

[@salamjihad3449]

dont let it bother you !! thats all she knows ! you probably know way more in other subjects !

[@67comet]

Improving every time you post a new video. Keep up the good work, listening to your explinations about all things Astrophysics is wonderful.

[@bmenrigh]

The quality of your content is going way up. This video was fantastic. Good research, great presentation.

[@Biomirth]

This is so so good Becky! I've never seen anything like it that takes us quickly and precisely through the understanding of galaxy cores over a century or research. If the BBC or NBC were to call you to redo this for them it would probably take 10 episodes and yet you condensed the material here in such a way as to be perfectly comprehensible for someone intermediate in understanding of astronomy. I had bits and pieces of this knowledge beforehand and now I have a strong sense of the research progression. As you said at the beginning it's a strange and almost miraculous thing that you can casually mention that of course all galaxies have a black hole at the center. The journey of this knowledge is such a testimony to the power of collaborative research over time it must rank up there with the best of the best of scientific discoveries that only happen over time.

[@Chew1964]

The best, most concise history of astrophysics on the webs. Thank you.

[@landrybeck]

I'm so glad I found your channel, Dr. Becky! You make Astronomy and Physics FUN, relatable, and understandable without being condescending about it. There are so many scientists out there with channels who present information with a very smug and high-minded approach. With you, it feels like we're all just hanging out in a casual cafe learning how we believe the universe works. Thank you so much for the quality content.

[@zapfanzapfan]

Wait, you got a PhD at 26? Damn! :-) Very nice history lesson!

[@realitycheck3363]

Yea, apparently PHD's are not what they used to be.

[@vikingsoftpaw]

@@realitycheck3363 Or may she's really bright!

[@dreamdiction]

@@vikingsoftpaw they give PHd's to anyone who agrees with all the previous bullshit.

[@than217]

Whenever she said how old she was I took a good long look in the mirror. Pondered what I've done with my *cough* _35 years_ *cough*

[@dreamdiction]

@Open Skies Science has become a belief system, like religion. There is no evidence that relativity happens anywhere other than in the mind of the person thinking about it, there is no evidence that photon particles exists anywhere other than in the mind of the person thinking about them, there is no proof that black holes exist, there is no scientific proof of cosmic inflation (big bang). Physics is real but cosmology is imaginative speculation, like religion.

[@markmaurer6370]

I think that this kind of historical focused science teaching is especially important for skeptical laypeople. You can list lots of facts about the cosmology of the universe, and I can list a bunch of facts about the Star Wars universe, and some of them would sound very much like your facts. Facts are easy to dismiss especially because fan based trivia is also rational and consistent, but totally fabricated. We're constantly bombarded with nakedly fictitious facts. Telling the human narrative is not only compelling teaching, it helps make science accessable to the emotional and sympathetic part of our psyches. Maybe a misstep for scientist, but very important for laypeople who might have suspicion born of ignorance.

[@asshatteryengaged813]

@Mark Maurer : Very well said - I could not agree more. I'd only like to add that science has not nor will ever be infallible in the conclusions it draws. However, as more evidence/observation is accumulated, science self corrects and evolves. It's an incremental process that takes time. @Dr. Becky : Just think, two years ago right now you were scrambling to complete your PhD. Congrats on your accomplishment back then, and we look forward to your many contributions to human knowledge in the future. Thank you again for these videos.

[@pseudorandomly]

@Mark Maurer Not only does historical context assist those "who might have suspicion born of ignorance", it's also useful to answer the often-heard layman's question, "How do we _know_ that?" The answer is often, as in this video, a very long chain of observation, analysis, and confirmation. It's useful to be able to tell the story in this fashion, at least in a rough way, so they get the idea that this is evidence-based conclusion, rather than simply being made out of whole cloth.

[@tetsi0815]

Exactly! How often I met people who were convinced that for example Einstein sat at his desk just making everything up and then postulating it to the world. Once you explain to them that Einstein actually tried to explain experiments that had been done and that did not agree with the known physics of the time and that a lot of people actually contributed to / shaped his ideas they understand why we know, what we know and especially why scientists can - even if they don't know the 'correct' explanation - rule out wrong answers. It becomes less arbitrary to them at that point.

[@e1123581321345589144]

Totally agree. It's nice to see how the understanding of a concept evolves over time. When debating scientific discoveries I often bump into people who don't understand the scientific process and think everything is just in a theoretician's mind.

[@grayaj23]

I agree. What I find the most compelling is that you can take a slightly difference "slice" of science and a lot of the same names linked to the same ideas will appear there as well. This mesh of ideas spans across the entirety of modern science and it becomes clear that if some little obscure prediction from way back in 1914 had been wrong, smartphones as we know them would not exist. The fact that a PET scanning device even *exists* reinforces the standard model of particle physics. The basic function of television is inextricably linked to how LEDs operate at subatomic scales. "That thing you're holding in your hand, with the video screen, condenser microphone, filmless camera, speakers, GPS and motion-detection all by itself demonstrates just about the entirety of the science that you're scoffing at."

[@gasdive]

Great video thanks. Love that Feynman always seems to pop up somewhere!

[@MendTheWorld]

gasdive I wish "polymath" weren't such a goofy sounding word for describing someone like Feynman, but he truly was one.

[@fordsfords]

The first 50 seconds really touched a passion of mine. I love hearing what led to established science. I could almost spend my life just watching a channel dedicated to that. (*COUGH*objectivity*COUGH*) :-)

[@MendTheWorld]

Steve Ford It's almost inconceivable that the same sensory windows and cognitive abilities that would enable our hominin ancestors to survive on the Africa Savannah would later enable the discoveries that Dr. Rebecca describes and participates in. (I don't feel quite comfortable calling her "Dr. Becky"). Consider that vision--the most remarkable of our five senses--evolved on the African Savanna to provide us with certain essential information about our immediate environment, that would enable us to survive long enough to reach sexual maturity _AND_ that we would simultaneously develop the cognitive and mechanical capabilities to extend the scope and range of our vision, in distance, resolution, and wavelength, to enable us to "see" (in the _broadest_ sense of the word, Ha-ha) to the farthest edges of our universe... _AND_ to make at least partial sense of it all. And consider that the same social skills that enabled us to form successful hunting parties and eventually agricultural communities, would, with some minor tweaking, one day enable us to invent complex language and scientific method. Please pardon me if I'm rambling, but thinking about and looking at pictures of distant galaxies and quasars, and glowing clouds of hydrogen gas, not to mention the very concept of **OBJECTIVITY** have got my mind spinning like a spiral galaxy bound together in a cohesive unit by "dark matter" It's so cosmic!

[@richtaylor6039]

Discovered you videos this rainy Saturday afternoon. Very enjoyable, looking forward to your book in September. :-)

[@DrBecky]

Thanks Rich 👍 hope you like it when it comes out!

[@billb2176]

Geez Becky - just discovered your channel and couldn't be more impressed with the summary of a few decades/centuries - impressive!!!

[@BoldrepublicRadioShow]

I was having fun watching your notes move around, change pages, and even vanish and come back, as you spoke.

[@frankbrown6716]

I am 73 years old and I lived through the history you talk about in this video as the information made its way into the public awareness, I graduated high school in 1964. You talk about advances nade in the sixties and seventies like it was a long time ago. I had to stop and think that 60 years ago is a long time ago, even though I was there. Thank you for all you do to make the latest advances in cosmology and also particle physics availability. Also thank you for your contributions to the current advances in astrophysics.

[@InfiniteRegress]

This is excellent, Dr. Becky! ^_^ If you don't mind, I have a couple of black hole questions for which I haven't been able to find any answers anywhere (and I've really looked!). Why does anyone think anything can fall past an event horizon at all? Since time is flowing more slowly closer to the event horizon than it is farther from the event horizon, surely nothing in the entire history of the universe has ever crossed any event horizon, right? When it comes to relative motion, there is of course no preferred reference frame (although I would say the CMB is the best candidate), but when it comes to relative positions and gravity wells, wouldn't a reference frame with a faster flow of time farther from gravitationally induced time dilation effects be the one whose perspective "overrules" a slower one? Black holes could still grow because, while stuff that does fall toward a black hole could never cross the event horizon, the black hole together with the infalling stuff would then define a new, wider event horizon that later infalling objects could never cross, and so on. Black holes would effectively be event horizon onions! And wouldn't this also mean that singularities are impossible to form, too? As something compresses toward being within its own Schwarzschild radius, time moves more and more slowly for it relative to the surrounding universe; so, for example, the flow of time for a stellar core or neutron star that is collapsing into a black hole should just asymptotically become slower and slower, and since the frame of reference that gets to say what is "actually happening" should be the faster one, no black holes anywhere "actually" contain singularities--only an original, increasingly slow "seed" around which are the layers of newer event horizons. That was supposed to count as just one question, hah. :P My other question is about supermassive black holes and a process by which they might have formed. I've read about the direct collapse process by which the essentially zero metallicity gas of the early universe might have allowed for the formation of "stars" that were many tens of thousands of solar masses but almost seamlessly continued collapsing past that stage into supermassive black holes. I was wondering if, instead of by way of some sort of collapse, supermassive black holes might just be solar system scale regions of space where a couple hundred million or so stellar mass black holes and neutron stars happened to gather, pushing that region to its Schwarzschild density. A 1 billion solar mass black hole has an event horizon radius of almost 20 AU, which means that its density is less than 20 kilograms per cubic meter, or 50 times less dense than water. Having 333 million 3 solar mass black holes in that region would still allow for almost 15 lightseconds worth of distance between black holes. So, how plausible--in terms of time for the Population III stars to create a bunch of stellar mass black holes that could then collect toward a central region--is it that supermassive black holes could have formed this way? In other words, if we had magic vision that allowed us to look inside of supermassive black holes, we'd see a whole asymptotically slowing swarm of stellar mass black holes. Thanks in advance! ^_^

[@mikefriend1514]

One of the great achievements of the modern age of man is the dissemination of scientific learning. And the amazing fact that I seem to have moved seamlessly from knowing bugger all about the universe to suddenly having words like cosmic background microwave radiation, red shift and super massive black holes happily bouncing around in my head as if they always belonged there.

[@dimitriedgarmetz3147]

Schwarzschild is pronounced: Swarts-shield not ...child or ...chilled as many english speaking say erroneously. Translated from German: Black-Shield Coincidentally appropriate, considering he define the formula for the radius of a black hole, establishing where the event horizon or the 'black-shield' At the event horizon the Time comes to a complete standstill, there's complete length contraction and charge reduction. See my video for the calculation: kzbin.info/www/bejne/noqwp32rop6SetE

[@jamesdriscoll9405]

Some papers written during WWI, while he was serving in the artillery

[@xavierlopez7717]

I really enjoyed this video, it's amazingly well told. I would just like to point out, for anyone interested, that the electron degeneracy pressure which stops White Dwarfs from collapsing is NOT due to electromagnetic repulsion between electron as stated in the video, BUT to Pauli exclusion principle. en.wikipedia.org/wiki/Electron_degeneracy_pressure I suppose Dr. Becky perfectly knows this, and just told it that way for not making the video too complex, so I'm just saying this in case someone wants this extra info.

[@PerrinMathieu]

Yes! I'm glad to have checked in the comments before pointing the same approximation at 7:30. The white dwarf is globally neutral, so the electron-electron repulsion is counterbalanced by electron-nucleus attraction. It's really this quantum phenomenon that is at stake, and it makes them even more amazing!

[@carlg5086]

Dr Ph.D Astrophysics certificate in the background.... Winning! 👍🏻🇬🇧

[@no_handle_required]

Other than Feinman, this is the first person who can hold my attention for an entire topic. So easy to listen to.

[@jwarmstrong]

Dr. Becky your nobel prize in astrophysics is waiting for your paper. Please send by overnight mail.

[@byrnemeister2008]

Superb video. You are producing some excellent science content. I like all the links to the source papers in the notes. This all must have been a lot of work. Keep it up.

[@Malandirix]

Really great video and presenting. Even rivaling those who've done it for years I think.

[@erikthedragongeek7657]

My new favorite youtuber! Loving these videos already, great work, always been a fan of Astrophysics and Astronomy, kinda runs in my family. Robert L. Staehle, my uncle, and Lori Paul Staehle my aunt are in the field..

[@Carisus]

Totally referring to them as the "tensies" from now on. (tensy's?) (tenzies?)

[@pawe3039]

And never by "noughtsies".

[@baronet68]

@@pawe3039 I agree... that sounds too much like 1940's European occupation. ;-)

[@payday510]

Thanks for taking the time to do this. It's always great to hear experts discuss subjects they're passionate about. Can't wait for more :D

[@urmeti]

More bloopers, pls ! xD

[@blackthorne-rose]

"Flurrin"="flowing" ... "Exactly the same...pretty much.." lol

[@pkiser99]

Brilliant recap. I graduated from high school in 1976 in a small town where the science teachers were using science that was already 15 to 25 years out-of-date. I have been able to stay up with the advancement of new theories, but not the work that led to those theories. This helps to fill in the gaps. Thank you.

[@philbuglass4857]

Very interesting stuff... I knew a lot of this already, but not the historical context. Also, thanks for showing the photographs of the scientists! Interesting to put faces to some of the names we hear all the time. Be honest, readers, how many people would have recognised *anyone* other than Einstein?

[@volkerbuescher]

Feynman, Hubble, Lemaitre because of his soutane, maybe Oppenheimer...

[@aidanlevy2841]

I would have recognized Dr Becky too :)

[@philbuglass4857]

Sorry, I forgot Hawking was in there... Still, he is more a contemporary than historical figure, which is probably why it didn't click.

[@mal2ksc]

Hawking, Feynman, Zwicky, Bekenstein, and Jocelyn Bell. I'd consider all of them to be on my "I know who that is on sight" list. Probably some of the others just aren't coming to mind right now. Oppenheimer I'd know, but have to think about a little bit. Of those (including Oppenheimer, I know his voice better than his face), I don't have a mental image of Zwicky's voice but I do for the others

[@lesconrads]

Your audio and video did make a huge jump here - amazing! Thanks for spending the time to explain your field to the public.

[@SpoopyGamer]

*clears throat* YAAAAAAAAAAAAY DR BECKY!!!!

[@williamtessier5449]

Your channel has become my favorite on youtube. I look everyday for something new form you, knowing it will be most interesting, and i love that. You are young and you present it in a fresh way every time. Please keep up the GREAT work.

[@peterbateman74]

Is it fair to say that galaxies are just accretion disks for their black holes? Or am I overstating the importance of the black hole to the galaxy?

[@DrBecky]

I'd say that's a fair statement. The galaxy is intrinsically tied to the black hole - any material pushed towards the centre, in theory, will *eventually* end up as part of the black hole

[@peanut12280]

Great content, Dr. Becky. I love listening to your episodes because I feel I always learn something. And you do it while just being you.

[@bloody_albatross]

Very interesting video! Just one thing: it's not "Schwarzs-Child", it's "Schwarz-Schild". "Schild" being pronounced somewhat like "sheeld". It means black shield. :)

[@Veptis]

phenomenal effort. I really hope EHT publishes soon and the 2020s become the decade of imaging super massive black holes surface.

[@garethjohn3389]

Excellent video! Interesting fact that I've read before: Karl Schwartzchild calculated the event horizon when he was in the Russian army on the eastern front of WW1 in the trenches!!!

[@timkratz742]

He is called Schwarzschild and pronounced Shvahts-shill-d. Has nothing to do with children. Funnily, his name means "black shield" in German which is quite literally what a Schwarzschild-radius looks like.

[@zaphod333]

@@timkratz742 Being late to the party, it's ˈʃvartsʃɪlt to be precise. 😜 Glad I'm not the only nitpicker.😇 I know it's hard though, and it doesn't make the slightest dent in my appreciation for the channel either.

[@tdoubt100]

One of the best documentaries I have ever seen! Thank you Dr. Becky! I have watched this three times as the density of information is phenomenal and the history content is sublime. I love the story you weave right up to the present day. Thank you so much for this!!!

[@lachezarkrastev7123]

Those eyes are hypnotizing :)

[@nagualdesign]

_facepalm_ You do realize that it's 2019, and that objectifying women makes you look creepy, like Borat or someone from the 1970's, right? You might as well ask her to unbutton her top! She's an astrophysicist and this video is about astrophysics, and you want to comment about how pretty she looks?! Nobody is interested in reading about your sexual proclivities, thanks all the same. Maybe you should think about keeping those kinds of thoughts to yourself.

[@lachezarkrastev7123]

I like her eyes, what is your problem?

[@MrMbc77]

nagualdesign You clearly don't know what objectification is and you undermine those who are actually objectified.

[@nagualdesign]

*objectification* _Woman:_ [Spends 25 minutes talking about astrophysics] _Man:_ You have pretty eyes

[@lachezarkrastev7123]

You are pathetic. Anyway, if Dr. Becky is offended my sincere apology! ... but I do not think for a second she has so simplistic way of thinking.

[@slayerem]

Adorable! Your passion for your work and your ability to explain it to us, non scientists, surely makes you more than a "tiny" piece in this massive jigsaw that fascinates humanity for over a century now.

[@leslieviljoen]

This is so fascinating, thanks for putting it together Dr. Becky!

[@skyrockit8271]

BEST VIDEO YET DR BECKY ! ! ! So much wonderful background and history ~

[@redhaze8080]

That was a really quality vid hey. Great work Becky!

[@grywacz]

Showing context and the history of thought and discoveries, as opposed to just the latest state of knowledge, is how one makes science approachable. Thank you for this great overview.

[@the1khronohs40]

YES! Exactly! Schools focus way too much on ´how´ and ´where´, and not nearly enough on ´WHY´! I too struggled a lot in school because of this... Anyway, I love that you bring your fascinating work to youtube, and take us along for the ride. THANK YOU!

[@cernunnos_lives]

You are amazing. Pure content, passion, and no fluff. Very few can hold this content cohesively to making a great point. History is even brought to the fore! Thanks.

[@Totumfacky]

Thank you for publishing your videos Dr Becky!

[@zaphodbeeblebrox1130]

Very good video. Congrats. As a tenth class school student, batch 1997, I conjectured that, given the published age of the Universe, every galaxy does probably have a supermassive black hole at it's center, while smaller black holes can certainly form from brown dwarfs, doing a merger with white dwarfs and neutron stars. OK, then bye.

[@Dovil3334]

Thank you for all the work you're putting in your videos. It is a real pleasure to learn from your videos.

[@AirCommandRockets]

Great video and very informative! Keep up the great work :)

[@TeddSpeck]

Just want to say thank you for making this Dr. Becky. It's wonderful to follow the history of how we gain knowledge and to see your excitement at being part of it. Just think of all the great things you'll be involved with in the next 40 or 50 years of your career. What will they be? Probably things you can't even imagine now.

[@Arfonfree]

I so enjoy the opportunity to bring my knowledge of the universe up to date. Thank you very much.

[@tjairicciardi9747]

really enjoyed the history of how we arrived at our current understanding of back holes. Excellent video

[@e1123581321345589144]

Really love this approach. Education on the scientific process is just as important as education in scientific facts. Keep up the great work Rebecca and thanks for this. I know how time consuming these clips can become especially with this amount of research behind them so thank you.

[@sailaway1015]

I used to watch a BBC show from 1978 called Connections, with James Burke. Three seasons, and 40 episodes He would weave his way through history showing certain things were invented or developed. Your presentation here, reminded me of the show and how no thing is developed in a vacuum.(no pun intended).

[@ValeriePallaoro]

Thanking you for a previous video that I watched in which you explain how the colourisation works on star photos and Im no longer focussed on 'how did they get those colours' but can enjoy the pix for what they are. A late thanks but full hearted non-the-less.

[@Dappdude]

That was a great video Becky! :D Love it!

[@spacemissing]

It's sort of strange that we learn so much so fast and still know so little about the universe. Enthusiasm for the subject leads to great discoveries. Keep up the good work, kid.

[@RaumBances]

Excellent video. Thank you so much and congrats for being a part of the discovery and understanding.

[@peterpowis4145]

Superb video! I was sooo tired last night and needed to sleep, but then started to watch this and it was so interesting, I just had to pick up a notepad and jot down different facts.... I managed to watch the whole video (was a real struggle because I was so tired) but I was so pleased I did...and fell asleep immediately after. I just love astronomy and can't get enough of it. Looking forward to more of your videos....

[@stevensalisbury7913]

Thanks Becky, just discovered you a month ago. You explained the development of galaxies, super-massive black holes and quasars that I been wondering about since being a kid in the 1960's when quasars were discovered what all of this was. I love your presentations. I'm in Internal medicine but love Cosmology. Keep up the good work

[@geoffbuck6865]

Thoroughly enjoyable and informative explanation of the topic, without any of the artificial and somewhat patronising 'hyper-enthusiasm' seen with many science-popularists these days. Keep up the good work of keeping us laymen abreast of astrophysical developments.

[@Dr.LairdWhitehill.Astronomy]

Thanks! Do you realize that you are talking to me, a person who has a PhD in astronomy (1972 under Carl Sagan) who had Salpeter for stellar structures and Penrose for general relativity. Do you realize that I am your audience. Your very best audience. With all the background to understand everything you say. It’s as if you’re talking to me and only to me. Thank you. Very much. (See me on Clubhouse, 11pm, eastern, where I answer astronomy questions). You do a great job.

[@RichardHowie]

Dr. Becky is brilliant and very easy to understand! Her voice is mesmerizing!

[@TheSadButMadLad]

History and science together in one video. Wow! Nicely done video with good editing and nicely presented facts. Did I say it was nice. ;-)

[@PhilFogle]

Congrats on the paper! Great history too. You are now part of an esteemed tradition that includes some of the greatest minds of all time...

[@peterstrong772]

You are definately the best at explaining how the universe works by our understanding, I have always been confused by the expansion theory, but not since watching you, I look forward to more of your videos, and hope you get more limelight, you deserve it.

[@summitap1]

I love that you put the pictures of these scientists up :)

[@juanstepbehind]

These extended videos are awesome!

[@wavemaker54]

Dr. Becky, that was simply fascinating, amazing, and extremely interesting. Thank you.

[@paulrussell1707]

Hi Dr Becky, First of all thank you, you communicate difficult concepts so well that even a high school drop out like me can follow you (i think). I have only come to science and more particularly physics later in life.

[@edturnbull4446]

This is a very good explanation and provides a succinct history of the development of the science involved. It also provides a glimpse into what motivates Dr. Becky and others.

[@plastonic]

Dr. Smethurst, thank you very much for this video. This kind of historical perspective is very useful even for us non-professionals who just want a look into where science currently stands, but also how we got there. Hat off, hat tip, and cheers.

[@wicked1172]

Thankful that I took basic Astronomy, which helped me to keep up with you as you moved along. Tip of the hat to Connor S. for bringing up the importance of peer reviewed science.

[@AbdulAbulbulAmir]

Yes. If only some of the maths and physics had been explained instead of just giving facts, I'd have learned a lot more in school. Still, I'm 72 and now learning from you. Thank you so much.

[@EmergentUniverse]

Hi Dr. Becky, Wow, that was an amazing history lesson. Well done! It is most certainly not the end, and if you step back from you timeline, leading up to SMBH in the center of every galaxy then you might realize these SMBH have far more effect on the universe than popular theory suggests. In particular, all these SMBH implement the "Big Bang" timeline, not by exploding, but by jetting plasma from the interior. (GR does not apply in fundamental plasma). This is also the root cause of inflation, because new graviton particles ("spacetime particles") are flowing out, while at the surface of our universe's bubble, gravitons are decaying and leading to the formation of Hydrogen which flows back towards the galaxy center of mass. This decay on the surface is also known as the CMB. It totally makes sense. I can provide the next level of detail f you are interested, including how the two fundamental particles combine into the standard matter particles and gravitons - very simple constructons. Oh, this mechanism is a big part of the dark matter mystery too. Best, Mark

[@mjaerkens]

Nice and steady subscription growth! Keep it up. Video was really good quality and very explanatory. I wonder how many subscriptions it will take before this channel goes blackhole.

[@Vicnsi]

19:41 "so at the start of the 90s, first of all I was born..." woohoo, that was the best part! 🙌🏼