How massive can black holes grow?
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- čas přidán 15. 06. 2024
- How heavy is the heaviest black hole? Can it get any heavier? To understand that we have to understand how black holes grow and how they're limited by the physics of accretion of material. So it got me wondering how long it would take to grow a black hole that contains all the matter in the entire Universe... Of course, it turns out that's not entirely physically possible...
Here are the links to all the papers cited in the video:
Shemmer et al. (2004) - arxiv.org/pdf/astro-ph/040655...
Regan et al. (2018) - arxiv.org/pdf/1811.04953.pdf
King (2015) - arxiv.org/pdf/1511.08502.pdf
The mass of the entire Universe estimate: www.rostra.dk/louis/styr.html?...
My new book 'Space: The 10 Things You Should Know' is coming out September 5th! You can pre-order it from amazon here: bit.ly/SpaceDrBecky
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My sister made the frame in the background as a present when I passed my PhD. It's not a real certificate. It's a decorative print for my office which I love. My sister does commissions: megansmethurstdesign.wordpres...
Dr Becky also presents videos on Sixty Symbols: / sixtysymbols
and Deep Sky Videos: / deepskyvideos
Dr Becky Smethurst is an astrophysicist researching galaxies and supermassive black holes at Christ Church at the University of Oxford.
drbecky.uk.com
------------ - Věda a technologie
I appreciate your effort in making everything you talk about interesting and easy to listen to. Never stop!
nonsense for morons on a baal!
George Sanford what are you trying to say? Your response makes no sense.
Frank Olsen I think she explained it well. She talked about the limiting factors of black hole growth, and she showed that chart of the maximum growth in relationship with the black hole’s spin, so yes she did answer the question.
George Sanford Well, I don’t know what world you believe you live in, but it certainly sounds a lot more boring than reality.
But in the end you’re probably just a troll. In fact, I think almost certainly, since no one would ever take you seriously. So in that case, well played kid.
@@GabeTStarman Ok fundy zelite enjoy your ball religion
The production value of your vids just keep getting better and better! Really awesome nerdy technical stuff presented in such a fun and lighthearted way, thank you Dr.
Thank you so much for your hard work on these videos! You are wonderful at taking complex things and chunking it down to concepts that are understandable. If you ever offer an online course(beyond what amazing stuff you do here), please let me know and I'd sign up instantly.
Also I pre-ordered the book!
"My arch nemesis at the minute is grass" I laughed at that way too much xD
It takes skill to deliver an accessible explanation of so many concepts in one video, nice job.
I could look at and listen to you all day. Informative video. The bloopers at the end was also funny. Looking forward to more.
2 of my favorite things, You AND Jeniffer Lawrence , in one video.
I love your enthusiasm and passion. And how you talk with your hands.
Thanks for your content! You have a very easy manner and explain things quite well. Keep up the good work; a star in the making with a nebula, you are.
Very nice talk on a complex subject. Many thanks Rebecca.
This is brilliant! Such a great explanation. Really enhanced my understanding. Thank you!
so happy i stumbled upon this channel. it is always a pleasure to watch your videos
9:55 “wwwwweeeeeeeeeeeee!!!!!!!!”
That’s all I can offer on this video. I ain’t none too smartest. 😆😆
I can relate to that. When stuff goes over my head I like to use the Ralf Wiggam response, "My cat's breath smells like fish" hehe
Watch "Maxwell The Pig - GEICO Insurance" on CZcams
czcams.com/video/swlC1Y4U0KE/video.html
Mick M Ha! My wife and I usually go with Ralph’s “so...you like....stuff??”
A Lost One
The answer to... What did the snail say when it got a ride on the turtles back
ALO, Funny... Thanks!
2:27 "Depending on the accretion dixxs temperature"
My chuckle moment of today :p
I was expecting this comment
I was not expecting this comment
You do an excellent job at explaining such complex phenomena
Black hole: I will eat everything
Physics: You can‘t
Black hole: crying
I appreciate your ability and attitude for science education! This is good youtube channel.
That is insane, I cant even wrap my head around something of that mass! Thanks for the explanation, very compelling indeed!
Awsome,beauty,humor,and brain do mix very well. I like yours video, thank you
You put the dart in the bullseye once again! Love the introductions of comic spoofs from modern media. It really lightens the heavy material that seems to broaden the appeal to include more folk. I'm intreagued by your prep work and would luv to see your notes. Not only fo you not refer to them, you hardly take a breath for the entire video. That's your enthusiasm & excitement from how much you enjoy what you are doing! 😎
Thanks for including 3C 273 -- my favourite object to show people at public viewing sessions
Surely D_isco=2*R_isco
Love it 👏 if I could Knight you for that comment I would
@@DrBecky "Listen. Strange women lying in ponds distributing swords is no basis for a system of government." -- Dennis
"King of the who?"
"The Britons!"
"Who're the Britons?
Love the fact that they measured the R_isco in CM, LOL
and if you give it a pie it becomes L_isco
Thanks Becky for an intelligent and fascinating insight into the properties of black holes, you are a breath of fresh air, we need more people like you to educate and share knowledge, keep up the good work.
Very informative and entertaining, and you explain things clearly. Nice style of videos :)
Regarding the formation of black holes way back when in the early universe, it might also be interesting to mention a theory about 'direct-collapse black holes'. These are theorized to have formed during the 'primordial' universe, not from the death of a star, but directly from an extremely hot, unstable gas cloud. They're predicted to be able to weigh up to 10^4 to 10^6 solar masses at their 'birth'! Pretty crazy.
Anyway, yeah, I'm going to watch another one of your videos now, haha :)
This is the first time I’ve found a clear explanation for how a black hole forms the jet streams of a quasar. Fascinating video! Thanks! You look great, too.
I really like your content, just kind tripped over it this weekend and already watched a few of your older ones! Keep up the great work! I can listen to space all day! Your Friend from the Esoteric order of Dagon.
A young star in the making! Thanks for educating, please keep doing it.
Loved your explanation, makes my head spin, great video Dr Becky. FYI Real Madrid have an Isco too 😄
I love your videos, you make learning alot of fun and easier to understand. I can't wait for your book to hit the market. Please keep the amazing videos coming. Much love from backwoodsTennessee. 🤣
That was Great!!! Never seen anyone explaine that before, and I watch a LOT of this stuff.
You are awesome ,, love the way you share all this ,,the more uou share the more I need to learn ,,, keep on growing
Amazon to notify me when the book is available. Since I don't have you available to tell me bedtime science stories..... I got the book instead. :P Love your videos.... awesome.
Another fascinating topic. I may not follow everything you discuss, but I still learn something new every time.
I do have one request - given the enormous size and the huge variation in scale of just about everything in the various images you display, would it be possible to add a legend or scale to these images? I often get lost wondering whether a galaxy you've displayed is tens of thousands light years across or a few million.
I love your videos Dr Becky, they are always so interesting and informative not to mention entertaining...also it always makes me laugh when you use the word piddly.:)
It’s one of my favourite words 😂
I love your videos so much I pre ordered the book
Thanks 🤗👍 you’re awesome for pre- ordering 💪
Thank you so much for uploading this video. It is helping me to get through the pandemic!
It was discovered in the 50's in mexico in tonazintla puebla radio telescope, and it was in the catalogue number 618, hence the name ton 618, but still they can't see it's host galaxy due to be so bright the hyper luminous quasar that it almost blocks the whole galaxy
That must be annoying for intelligent life trying to study electromagnetism in that galaxy, their radio waves are always being jammed!
I don't know BUT as it boardcasting then all of them OR nearby frequency distorted at the same slice of time?
Very interesting lecture. Thank you.
THANKS ! Great Lesson ! Good Luck on your allergies. You remind me of Dr. Wendy O. Welch. Thanks for learn'n me! Enjoyed the topic !
Thanks Becky, learned something new today ... size limit of black holes and them winking out.
Thanks for the great video Dr.. One of your guests asked a question that most laypeople wonder (because we just don't know enough to not ask) and that is: "Tom Hathaway
- Wouldn't a black hole with all the matter in the universe in it essentially be the same as it was before the big bang?" PLEASE address this because if you don't we'll go around spreading this rumor and it'll all be your fault. hugs & kisses
2:28 did I hear that right? 😂
A Freudian slip, I hope 😄
Hahaha
Awesome video!
4.38 that's going to be my new tattoo! Wanted black hole tat! That's the one! Thanks Dr bex xx
Of all the youtube and other hype that's followed the pictures of the supermassive black hole, this is by far the most interesting calculation and conclusion I've heard. Before this I always thought that black holes would just continue to grow and grow over the age of the universe. Now granted over trillions of years mergers will produce black holes larger than this limit in the black hole era, but it's interesting to know that before then the size will be limited.
In with a bang,out with a whimper? This is beginning to sound like an Azimov story!
Maybe "The Last Question"? Or "The Final Question"? Its been years!
I enjoy your vids!
Keep em coming!
Thanks. Very informative.
LOL I love your blurb inserts.
I am delighted to learn about extraterrestrial space by watching your talks! :)
Love the effort you take in simply explaining some rather complex concepts. Any chance of tackling dark energy?
It’s on the list don’t worry 👍
You are so smart great job 👍 love how you explain
My favorite channel.
That book was a Fantastic read. Anyone who enjoys Dr. Becky already knows this. Thanks for the video.
Nice closing line in this video :) Sort of dramatic and funny :D
I've actually been thinking of galaxies as giant accretion discs for giant black holes. Glad to see that wasn't such a crazy idea! :D
nice explanation
Great stuff! I always learn something from you. I was wondering how you would factor in the expansion of the universe into those 7 billion years. And of course - you know what's coming - what happens when you factor in dark matter and dark energy?
Dr. Becky - Please make a video covering Time Dilation. Many thanks and love the video
My childhood illustration of a black hole was Figure 14-17 from "Astronomy: The Structure of the Universe" (William J. Kaufmann, III (1977) p. 449). I have a copy from the same printing in my lap as I type. There's a lovely half-tone illustration of the old spacetime funnel swallowing inbound line drawings of a radio, a loaf of sliced bread (the slices are falling out of the wrapper), a clawfoot bathtub complete with shower head, a quill pen, and, best of all, a dinosaur! Sadly, all that remains of these explorers after passage through the funnel is "Mass, Charge, Angular Momentum". I recently reacquired this childhood astronomy text because I want to compare what was known in childhood with what's known today in astronomy.
This video from Dr Becky has me dusting off my Kaufmann and opening Chapter 13, which describes the discovery of as much as was known about quasars in 1977. The big new anomaly to explain was the quasars' massive redshifts. Perhaps it was gravitational: the quasars could be supermassive so as to drag local spacetime to such an extent that the emitted light was redshifted at the factory, so to speak. But the masses required would undergo gravitational collapse and necessarily be black holes (what a foretaste of glory divine, I'm not a physicist but it seems they were reaching the right answer, but for the wrong reason). Another idea, that quasars represented nearby objects expelled from local galaxies at enormous speed, was easier to dispose of: if that were the case, there would be as many coming towards us as away (blueshifted v. redshifted), and all the known quasars were redshifted, none blueshifted.
The emerging dominant idea therefore placed the quasars out among the distant galaxies, but there were problems. The most distant galaxy yet seen was 8.5 billion light years away, and the quasars' redshifts placed them enormously farther away, 15 to 20 billion light years away, more than double the distance to the edge (in 1977) of the observable universe. The brightest galaxies then observed, cD Ellipticals, would never be detectable to the best telescopes of the day at such a distance, so quasars must be stupid bright: the equivalent of billions of suns, for them to be observable in 1977. So they must be big, to generate so much power. But they were observed to be variable, which means they're compact, much smaller than the diameter of a galaxy.
Kaufmann ends the section with these words: "When someone finally figures out what quasars are, mankind will have made a major breakthrough in discovering new laws of nature and will have arrived at a much deeper level of understanding physical reality."
Looking back from 2021, knowing only what I know (as the 52 year old version of the ten year old me that marveled at the Kaufmann book), it seems that the data on the true nature of quasars was staring them in the face. Accurately measured redshifts only fit great distances for the quasars. Late 20th century astronomers were masters (and mistresses) of accurately measuring brightnesses, too, for sure, with their super sensitive films, 200 inch telescope, heterodyning radio receivers and massive radio antenna arrays, etc. I'm sure we have sharper data now, but what they had was accurate to known limits of experimental error. Why was it still a question?
It seems now that there was the need for a leap of the imagination, to believe the data before them, which implied that the universe was far larger in size than that implied by the feeble light from the most distant galaxy then observed. What Timothy Ferris, in his "Coming of Age in the Milky Way", calls "Raising (and Lowering) the Roof".
Thanks for such a wonderful series, Dr Becky, it's a thrill to contemplate how much has been learned just in our lifetimes.
I just came across your site. You don’t talk down to people as others are. You are the best astronomer I’ve come across. I do have a question, when Pluto was photographed a few years ago it was bright enough to look like how the moon looks.. how could it be so bright when the sun is a pin prick in the sky?
The probe that took the image - New Horizons - had a very sensitive camera on board and opened its shutter for a very long time to collect as much reflected light from Pluto as possible
Thanks for your amazing videos :) Could you please expand on what you mean when you say that black holes will simply wink out of existence if they get too big to acrete any more material? Wouldn't they still just hang around?Thanks.
I know this is an old question, but I think I can help answer it. She doesn’t say the black hole will wink out of existence; she says the quasar will (the quasi-stellar object, i.e. the super-bright observable part of this thing). Meaning if it’s too big to form an accretion disk, then it will no longer undergo “luminous” growth, meaning we will no longer be able to directly see it in the sky. I think this is made clear by the blue line and the blue text in the graph at 10:44.
Hope that helps over a year later!
I don't understand, if Fgrav=Frad then that means stable forces, so means no material would be moving in any direction, so what the Black Hole absorbs/accrets energy from that dynamic equilibrium?
I like your bloopers at the end, your human side, funny and sweet :D
Got my book order in!
The reck it ralph cut away really got me
Dr. B, when do you move into your new digs? I want to see your diploma hanging on the wall! Thank you for another great video. It seems that so much astronomy is anti intuitive. Having a limit to how much material a black hole can accrete is an example!
Always nice to come across a fellow Ashley O fan.
I’m so glad someone caught that reference 🙌 did you see Miley sing it at Glastonbury?!
@@DrBecky I hadn't, but now I have. She's pretty great. She's come a long way from the Hannah Montana I remember. I'm also a pretty big fan of yours. Really excited to get a reply from you 😁
At 3:08 u called photons, particles... that's awesome!!! :)
It depends on how empty the space is around it. The size of black holes is regularly massively underestimated because the speed of their discs is underestimated given how slow the speed of time is near a black hole where time practically stops inside.
My wife was asking who is the Becky you keep telling me about astronomy from. I showed her your channel she's relativitly happy now.
She'll only be happy with a Minkowski coat.
Mine saw me watching her and told me I'm obviously not watching for the physics... Too smart for her own good.
So now you and the other Becky don't need to worry about getting caught............... That was a joke wife of Mike Spilligan.
im hooked on her videos!
Very interesting about the 'ISCO' as this reminds me about 'Hoag's object' and the area between the inner core and the outer ring where there is no stable orbit and hence a clear zone.
Hadn’t thought of that connection! Good one 👏
"ISCO ISCO ISCO ISCO" ok, I'm dead from laughing! :-)
You are amazing. Fun! Wow!!!! Thanks for the info.
Dr. Becky, you're so lovely and brilliant. Love your videos!
I would love to get your book, but it seems I can't get an ebook version of it here in the States. Bummer.
Hey Becky!
I would love to see a video about "how can black holes grow at all, given time dilation from the perspective of an external observer."
So not "how does matter fall into a black hole (coordinate transformation)." but "why do we see black holes grow?"
That would be awesome!
Love your show!
BH grows as matter accumulates because there is no such thing as a quantum singularity.
The gravity is curved space around the matter.
More matter creates more curvature.
If matter disappeared into a quantum singularity at 0,0,0 then there is less curvature and less gravity.
Therefore, there is no quantum singularity, because the gravity still exists.
There is a point of equilibrium as matter is compressed to reduce the curvature (i.e., the gravity).
Thus, the BH must grow in volumetric size as matter accumulates.
@@UltimateBargains no my question wasn't concerning the growth in matter-filled-volume because that's inside the event horizon and so we don't know and don't care.
No my question was due to the time effects near the event horizon. I know you can transform coordinates that matter viewed from the falling matter wouldn't even notic the event horizon and falls right through.
But what's with a external observer (us)? Wouldn't we see the matter slow down (shift red) until it asymptomaticaly stops outside/at the EH and so never reaches the BH so -> BH wouldn't accumulate matter inside its EH so BHs EH wouldn't grow?
I was never able to sort this out.
Greetings
Hey there I have have a question. If the big crunch did happen wouldn't all the black holes merge together?
Can you do a video explaining the final parsec problem?
I'm having a lot of fun pressing the '5' key :-)
Thanks! I never knew that 5 did that!
@@imgonnagogetthepapersgetth8347 as a mobile user, I can't help but ask what the key does?
@@rickedenvall6731 it repeats the last second of what you're watching.
@@imgonnagogetthepapersgetth8347 allrighty! Thanks alot!
Great video! Just one feedback: you don't need to insert random video clips throughout the video. Your videos are interesting enough by themselves :)
This is so true, these clips are just a distraction
They break monotony. That helps refreshing the attention of the viewer over 10 minutes of straight talking. It also adds a bit of a comedic edge which I'm sure she wants to have.
I enjoy them myself and is one proven methid of youtubers. Do what you like, re-evaluate and adjust IMO.
Dr. Becky, have you had any videos, or could you talk about Hawking radiation in regards to Black holes dissipating? Thank you! Keep up the Science!
A quick question: Wouldn't time dilation play a roll in how fast you would see the particles move around a black hole? Or is the black hole too massive to even have that effect on the particles moving around the black hole?
I like your channel keep up the good content.
Yes. At the event horizon time would slow down to nothing as seen by a distant observer. However, ISCO is at three times the Schwarzschild radius in the simplest case of a non-rotating black hole. Time would be seen running at 80% of "normal" there. And most of the accretion disc is at many, many multiples of ISCO radius, where the time dilation is much less significant. All the relevant formulas here: en.wikipedia.org/wiki/Innermost_stable_circular_orbit and here: en.wikipedia.org/wiki/Gravitational_time_dilation
Seems to me that once you get the innermost stable orbit out to the point where gas self-gravitates to form stars, you don't stop accretion entirely, because the stars and other things formed out of the orbiting gas would still interact with each other gravitationally, thereby still enabling momentum transfer so that the inner things can still spiral into the black hole in the course of causing other things to be ejected (or, given enough time, in the course of throwing off gravitational radiation). So the accretion process wouldn't look like a quasar any more, but it would still feed matter into the black hole, even if not as rapidly (and as the black hole continued to scale up, the rate would scale up accordingly as long as more material was available).
What do you personally think of the Alcubirre-White Warp Drive?
jw, the universe is expanding and acelerating in expansion as well? idk if you can but if you say take the derivative of that is that a positive number as well? Is the acelleration of expanding also accelerating. or in otherwords is the acelleration of expansion increasing or decreasing.
excellent explanation.
I wonder at what proximity to each other is there inevitable merging of two black homes, is it when their event horizons overlap if so why, or is it when the less massive singularity centre finds itself within the event horizon of the more massive black hole? Nothing can escape a bh or perhaps a bh singularity can? after all the laws of physics break down at the singularity.
The merging of the black holes is inevitable as soon as they are in orbit around each other. That's guaranteed by the gravitational waves which carry away orbital energy. Of course, for a large orbit the merger may be very far in the future, but it's no less guaranteed.
Makes me think that the big-bounce theory could be more likely than a single big-bang Universe. Always had a sneaky little penchant for that one over a single event.
Agree, makes more sense somehow 🤗
Quasars winking out and the expansion of the universe eventually making other galaxies unobservable makes me wonder how many other phenomena observers might have seen a few billion years ago that we'll never know about.
66B is the max mass BH can form an accretion disk, without an AD, it's not easy to see a BH across the visible universe, so, the fact is we are not really sure whether there are more massive ones hiding out there.
Well done Becky
SMBH can happen by 2 or more BHs combining so the age could be less than one half the MAX accretion rate. Many more SMBHs are required to support the theory. Another problem is Dark Matter which affects gravity around the BH.
Hi Becky, thanks for the content! But I have a question, what happens when the black hole hits that maximum size? I didnt quite get it, how does it stop growing?
It's not that there is a maximum size that any black hole could reach, but there is a maximum rate at which a black hole can grow, and, assuming one grows at that rate, the age of the universe puts a limit on how long the BH could have grown at that rate, and thus puts a limit on how big it can have grown. Just like your age puts a limit on how far you could have run in your lifetime, given your maximum running speed.
Q: How big can black holes grow?
A: Yes
I can clearly see that you're a lady who knows her facts. You always talk about all those intergalactic bodies so well. Such will to explore the universe, such science! But the big question here is: why would anyone ever dislike ANY of your videos? They're not only very informative, but. also... very impartial. I wouldn't be surprised to find out the truth about black holes, but, THAT will always be a mistery to me. Cheers! Rock on!
How does time dilation effect the speed of the accretion disk effecting mass calculations?
Thanks for this great video! Love your channel :)
There is a question which is killing me for years. I'm gonna ask it here in case you read that comment and have time to answer :)
From the point of view of an observer, away from a black hole, an object falling towards the black hole will have its time slowed down until being totally stopped at the event horizon. Is that right?
If yes, how come a black hole can grow, from our point of view (earth)? Any object (accretion disk, other black holes, stars, etc.) would never pass beyond the event horizon as, from our point of view, the object is frozen in time.
I know I am wrong somewhere, cause black holes can grow. Would you please be able to explain me what I am missing?
Please note that I am aware that from the point of view of the object falling towards the black hole, time passes normally for itself.
Thanks in advance :)
The black hole acts as though all the mass and charge that fell in is smeared out over the event horizon.
So mind blowing about the fate of quasars! Thank you!!!
It really is just 🤯🤯🤯 the things I study could just poof and disappear
متوهجة دائما في سماء المبدعين
i love how you're able to put all this in a way that makes sense to people who dont have the science degrees you have. also am i the only one here who finds you super attractive? >~
Book called, Space : Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.....the end.
And always remember the most important advice of all. . . .
Don't panic
And don’t forget your towel
Dang it! I missed so much information because I kept thinking about mergers...need to listen again.