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

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

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. 👍👍

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.

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.

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.

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.

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...

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.

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

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. 🥰🥰🥰

Interesting ✔ Good audio ✔ In focus ✔

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

Super massive "THANK YOU" for this video

What a fantastic story of science, well put together.

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.

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.

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

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

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!

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.

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

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

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.

Your passion for this and your joy in sharing it is fantastic. You also have a great balance in how in depth you go with every step. This was a great watch. Thank you!

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

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!

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

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

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

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

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..

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

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.

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

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.

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! ^_^

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?

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.

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.

More bloopers, pls ! xD

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

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

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.

*clears throat* YAAAAAAAAAAAAY DR BECKY!!!!

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: kzfaq.info/get/bejne/nr99qa2m0p_DdKM.html

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.

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!

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

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. :)

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

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*) :-)

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

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!!!

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.

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.

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?

Those eyes are hypnotizing :)

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

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.

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.

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....

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

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

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

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

Thank you for publishing your videos Dr Becky!

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.

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...

Thanks Dr. Becky Very insightful and makes me ponder

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

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.

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.

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!!!

My education actually did follow the order of discoveries fairly well from Newtonian physics to Quantum. I thought most would because generally that is how things make sense -- when built one upon another. I love the videos, and I hope your audience grows exponentially.

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.

I look forward to seeing your personal developing research and how it expands the black hole knowledge and how your research will propel others research. Congrats on being, as you say, a tiny part of this understanding, and kudos on including your work into the story. Most people would not feel comfortable in citing their own work into the broad spectrum of the research. It shows how influential your work is. 👍

Wow, that was some walkthrough. I loved the cartoon at 22:08. And the baby photo. ;) Interesting to think of Oppenheimer having to drop out for a few years in the 40s to build the A bomb. This was the first time I had seen him mentioned in another context. Anyway, thank you for these. It's wonderful to share all of this literally *awesome* stuff with people who can't do the math. ;)

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

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.

Very interesting. You succeeded in knitting together several concepts and observers' conclusions. Loved it. You are talking about many concepts I've come to understand over several years, with a basic understanding gleaned from Alex Filippenko's 96 chapters in his "Understanding the Universe, An Introduction to Astronomy, 2nd, Edition," a product of the Great Courses. Thank you, Dr. Becky.

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.

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.

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

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.

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

Great historical and scientific summary. This is not an easy task at all. I commend you for your talent and knowledge

Superb teaching and storytelling! Thank you so much, Dr. Becky.

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.

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.

How fascinating was that ! I am not bright, but I think I actually could understand enough to be riveted to how the history of a concept that a black hole might be real , developed. Well done, Doctor, and thank you for your time to construct this you tube so that people like myself can feel an inkling of why you are thrilled with this science. I look forward to more videos and hopefully to more understanding of these topics.

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.

Best paced and most enjoyable data-rich historical re-cap EVER! Doc... Outstanding episode... you musta knocked your pan in tryna zip through it but not zip past anything important.. Quality! as we say In Glasgow. for real tho' ?.. *every* one? even the irregular blobs and squiggles?.. cool sorta .. It's weirdly reassuring to know there's some regularity in the chaos.

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

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

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

I’m sure you’ve covered it in other content before but I’d love a video aimed at the….less academic of us about a few fundamentals about the way we see the universe. For example the concept of seeing back in time when observing light from objects as well as how different wavelengths of light help to see different aspects of the universe. Love the content, thank you.

And all that happened in 1 century, wow!!! Amazing video, thanks!

Very cool video with a lot of information, thank you. One simple thing you could do to improve your videos is to get a softbox or even just a white cloth in front of your light... it would make the light softer and take away those harsh shadows.

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.