This episode is a primary example of why this channel is so good. I could spend 15-20 minutes reading all the pop-sci articles on a story like this, and would only end up frustrated with pop-sci, and still not really understand what the research was actually saying or why it was important. In this particular case, the research is extremely interesting to me, and in 21 minutes you presented it extremely clearly and without overdramatizing anything! Thank you so much for the work you put into making these episodes, they are definitely appreciated!!
Maybe she could research her sponsors for at least 1 minute too? Maybe a quick "Google" is prudent before jumping on a "good deal" not to sell out peoples personal information, not providing any actual help. Promoting harmful psycological "help"?
If you can prove this, you can make a HIPAA (HIPPA?) complaint against them. The law is pretty generous here - all you need to do is prove that the company sold its users’ identifying info to third parties. Identifying info can be as simple as a name or an email address - it doesn’t need to be detailed. Feel free to ask me more about this law - I used to work in healthcare.
So does everyone else. If you don't want your info sold DO NOT use a online therapy platform. If your desire for a therapist overweighs your concern about data use, then use Betterhelp or other online therapy platform.
Ditto on dropping the BetterHelp sponsorships. It is disappointing that some of the best quality, well-explained science content on this site is invaded by marketing for a company that has consistently shown itself to be untrustworthy regarding their patients’ private health data and also the treatment of their care providers.
I'm surprised, I really thought she had dropped it after the last video got comments just like this one. That last video took me to the vlogger who just read out all the gory details of their past lawsuit. Absolutely insane
@@yrobtsvt especially when you live in the uk. I was stuck with a vodaphone contract I didn't have access to the account to. I couldn't even close the account when I went into branch with ID. I had to let the contract go unpaid and wait until the debt got bought out by local solicitors
Please rethink your sponsorship! "BetterHelp has agreed to pay $7.8 million in a settlement agreement with the U.S. Federal Trade Commission (FTC) over allegations of misusing and sharing consumer health data for advertising purposes."
Even though this video aimed to explain a very specific thing, it's one of the best summaries I've seen to explain what the different regions are around a black hole. It would be perfect if it also explained that the black circle we see (the shadow of the black hole) isn't actually the event horizon even though it's the image we choose to show whenever we mention the event horizon
A Brief History of *Time* is by Hawking, A Brief History of Black Holes is by Dr Becky- though I would assume she probably discussed Hawking’s theories in the book, the similar titles make me think you confused the two
I know, seeing her continue to accept their sponsorships is incredibly disappointing and I'll likely unsubscribe if she doesn't take accountability for it.
Wasn't the hole thing against BetterHelp that... it just hasn't worked for some people? Like every other form of therapy?? At least that's what I read / heard a while back. Don't know if there's new stuff out against them.
@@JordiVanderwaal They sold patient data to advertisers. They have a dubious record of checking credentials of the people they hire and a long, detailed history of substandard care for patients. It is significantly more than 'not working for some people'.
I'd love to see a side project where you have scientists explain what is on their blackboard in the background of interviews! And, do any of them just doodle up the blackboard for the interview, to mess with us?
Seriously, though, I recognize that Anton isn't a scientist like Dr. Becky, but he seems like an earnest enthusiast and I like hearing what interests him.
@@Kivikesku he always put links to scientific papers that he is describing in his videos and he also always mentions it(links to peer review papers) so how does that amounts to click baiting and sensationalism in your mind is beyond me but I'm sure you'll put some proof of that accusation. Even Becky (not just her but many other science educators) is following and liking Anton because he is humble, sincere and great science educator.
love astrophysics, going on to do it at uni. it makes me so happy to find a place where astrophysics can be explained without any arguments, thanks Becky :)
They're one of the highest paying youtube sponsors at present, because it turns out that scamming people with mental health issues is wildly profitable. Becky you should be ashamed of yourself. Unsubscribed.
@@mrdwets8952 If what you say is true, that's pretty simple to deal with. First ad after you learn of a problem "I'm required by a contract I deeply regret signing to tell you the following." That's neutral to the product so it doesn't violate any clauses meant to protect them from being called out, it doesn't say anything that could be sued over, but it does make it clear she's not espousing her own opinion.
Are there any companies that are sponsors of yt videos that aren't shady? VPN, supplements, privacy... They all have a stink. Just don't throw any money at them
@@stargazer7644 If she is contractually bound to making a certain number of ads, it would give everyone a lot more peace of mind if she said so in a community post.
For once I’ve finally read a paper before dr Becky covered it so I got to listen to her clear explanation to test what I got from the paper! Thank you Dr Becky!
I'm sorry Dr. Becky, your content is informative and amazing, but I had to dislike for the BetterHelp sponsorship. I'd tell my story about my really bad experience that reflects a large number of other testimonies from their users and therapists alike, but honestly today I'm just so tired. Mental health struggle is real, and people absolutely need to be able to seek out help for it, but BH is demonstrably not it.
Thanks. I did General Relativity based on Steven Weinberg's book in 1982. I never did any "application" of this work to astronomical observations. Great to learn about this after 40-odd years ....
I think it sounds like we have absolutely no idea what we're talking about. I think it sounds like we're tweaking the math to fit the model. With ignorant words being touted as variables like dark matter and dark energy. It seems like we have black holes in our math. The age of the universe sure went out the window with the James Webb telescope. I wonder how much money we've spent looking for dark matter? How many brilliant students could we have put through school? The answer is in humanity but we don't invest anything in that. The picture of the black hole is a complete lie. There's so many variables in that you could have made a Mickey Mouse picture.
When you get down to it the matter inside a BH isn't a thing, it's some kind of inversion of "thingness" lumped over an intersect that defines the point that matter was a thing at ..before mass just kept pushing toward it and broke something.
@@luke144 Obviously there's a lot of stuff in our theories that don't work, but some findings match our predictions, so it's likely that our current theories are at least close to the truth, even if they aren't complete. We shouldn't pretend that we really understand what's going on, but that doesn't mean that we know literally nothing either.
Dr. Becky, despite not understanding most of what you presented, I still enjoy it as it convinces me of how much I don't know. Bottom line is, black holes win!
Agreed, she has a great singing voice and I usually only get snippets of it in the bloopers And she could adjust some lyrics of songs to fit astrophysics better and be free of copyrights through parody law (at least in the US, not sure about international law on that)
If Doctor Becky has written any a full length physics filks I'd love to hear them. But what we see in the bloopers is the kind of thing I do all day at work singing a phrase that's on my mind (a customer's name I've just on a label, or whatever) and then free-associating another line or two of lyrics 'til I run dry. Very few of this "microfilks" ever get written down let alone developed into full songs; They're just created in the moment to be enjoyed in the moment, and then they're done.
It took me a bit to understand why the ISCO would be closer the faster the spin. You didn't explain that frame dragging affects the process and I had forgotten about it. Black holes can really be counterintuitive at times. Thank you for the video.
4:07 Technically there do exist trajectories within the ISCO that escape to infinity, it's just that trajectories that don't eventually either fall in or escape don't exist in that region.
Sure, but significant charge on a black hole would probably not last long. A positively-charged black hole would very strongly attract electrons, which would quickly neutralize the charge.
Dr Becky, I appreciate the work you do to promote sound science in an understandable way to the public. You're one of my favourite channels. ...BUT the continued sponorships from Better Help need to be addressed before more and more of us leave. You aren't just promoting an unethical company. You're also ruining your own credibility.
I notice that no one complaining about this company has offered any evidence against them. Just accusations. Nor have I seen any of the complainers offering any financial support to this channel. Talk about lack of credibility.
@@michaelsommers2356 maybe you should read the news more and TH-cam comments less. It's right there for you to learn, you choose not to because it's not spoon fed to you?
@@michaelsommers2356 Just accusations hm? Zero documented evidence of wrongdoing? No leaks? No controversies? No sketchy data selling/correlation? 1. Click the TH-cam Search input field. 2. Fill in "betterhelp" and press enter, or see the suggested search terms. 3. Scroll past the BetterHelp sponsored first 3 (or so) entries, if you dare to step out of your comfort zone.
It’s great that Einstein’s theories are constantly being validated, but after all of these years no one should be all that astonished that they hold up.
Honestly thinking of black holes, habitable planets, Space all give me hope because it means everybody were all worth something and our job is to become interstellar and reach higher consciousness to reach out full potential as human beings or homo sapiens sapien.
The improvement mentioned is relative to the chi^2 of 1173.12, so the very first model. As for the massively, I am assuming the second, whole number listed behind the / are the degrees of freedom (d.o.f.), basically how many data points you have minus the number of parameters of your model. If your model describes the data well, the chi^2 will be around that number. If you get a chi^2 value significantly larger than the number of degrees of freedom, that usually means your model is not good. If you get a chi^2 value much smaller, this usually means you overestimated the errorbars on your data.
Black hole question I've been having trouble finding an answer to; if time dilatation increases exponentially towards infinity as you approach the event horizon, wouldn't the black hole evapourate ahead of you as you got sufficiently close to the event horizon? They have a finite lifespan, so I don't think you could ever cross into it.
Well, in retrospect I suppose you would cross it, but not by falling on, but because the black hole will grow more before it shrinks, and so the event horizon would probably rise to meet and then envelope you, and then space/time role reversal or other weirdness may mean that it doesn't immediately(from your point of view) overrun you in the other direction? I dunno.
Though black holes are usually depicted as a a two dimensional hole, or three dimensional in the sense of a whirlpool shape, they're actually three dimensional "holes" right? I.e. you can fall directly into them from any direction. If that's the case, is the accretion disk a disk? Because of the spin?
No it's for the same reason galaxy tend to be 2d or any solar system. If u have stuff moving in 3d orbiting each other they tend to unite in one plane over time that would include the center spin unless something interfere with it. Cause if u think about it that the direction of all the gas and stuff united to before a star or planet formed would became the direction of spin for the object.
Thanks for the replies! Follow up....does the accretion disk spin independently of the black hole, or black sphere, and when we say a black hole/sphere spins, what exactly is spinning?
@@scottbadger4107 The spin axis of accretion disks are not all aligned with the black hole spin axis due to things like precession of the black hole, magnetic fields or the angular momentum of the material that formed the accretion disk. Spacetime is spinning, or twisting around. The spinning of space (frame-dragging, an effect due to general relativity) has been detected around Earth, and black holes drag space around themselves in an extreme way. The simplistic view of a non-spinning black hole is unlikely to happen in nature since the gas or star that collapsed to form the black hole would most likely have been spinning, since angular momentum is conserved. An accretion disk is also formed due to angular momentum of the matter around the black hole, and the spin rate is also increased by the flow (frame-dragging) of spacetime around the black hole.
Hello Dr. Becky. So nice this video. Congrats to Dr. mummery! Are you planning on doing a video on the evolution of supermassive black holes ft. Professor Hickox? Please say yes!!! 🙏🙏🙏🙏 Thank you in advance and best regards!!
I have few stupid/strange questions: * If BH have charge, is BH a monopole or a dipole? * Is it possible to theoretically spin up a black hole? * if a BH gets high rotation does the shape changes, if so if rotation is high enough can it change shape into torus, or brake apart from the angular momentum? * would such a breakup look like... big bang?
7:17 Matter that gos into a black hole ceases to be discrete, and also can't fission. The only thing happening in a black hole that has any high degree of chance to exist, is fusion, which happens with most all matter that enters it. It creates an element which atomic number would be written similar to 1E+100 (arbitrary large number). Despite the instability under less gravity for such a large element to exist is undone by the gravity preventing fission, since fission needs space, while the gravity denies this space to exist inside the mass of the black hole. You can't split apart if there's no room to split into. Much like 1 m3 of water can't divide into two separate parts if only 1 m3 of volume exists. Matter being compressed inside a black hole is being compressed into even smaller volumes than that of a neutron star.
GAAA WHY ARE YOU STILL DOING BETTER HELP ADS ?!?!? They are very publicly proven to not provide what they advertise. So many people have been vocal about their experiences it’s surprising you either don’t know or don’t care. There are myriad other businesses you can do ads for and I hope they only continue on your channel because of a contract. Ill keep checking back and probably keep feeling uncomfortable at the better help ads and tuning out when I see them.
Great shout-out for back holes! I never miss your episodes which really explain things so well that I, with an old biologist's maths (non)skills can get the picture without reading the papers. So, sorry BetterHelp, I don't need counseling to keep thinking about black holes and matters such as ' - - - whether pigs have wings' (apologies to Charles Dodgson) after Dr Becky explains it!
Mass. Determined by how other objects behave near it Electric Charge - Voltage. The amplitude (squared?) of the EM field. How do you determine this from a billion light years away? Spin - spin is rotational momentum (potential?), momentum is energy, energy is mass, mass curves ST, a black holes spin contributes to its mass. How is this measured vs mass? Conclusion: The EM field is independent of the curvature of spacetime if we can some how measure or deduce the electric charge of a black hole. Wrong? Right?
Question: What would happen if the spin was so strong the ISCO went beyond the event horizon? Or is that not possible, I don’t see why it wouldn’t be, would it be a way to explore inside the event horizon? Also wouldn’t that mean the “black” part of the black hole is more bright then it should be since the Isco goes beyond the horizon effectively reducing the size of the event horizon?
@@michaelsommers2356 Oh yes, I'm sure the $7.8 million they were fined by the FTC last year for selling patient health information to advertisers, which is a violation of federal law, was completely groundless.
@@michaelsommers2356 Maybe you have heard about Google? Posting links don´t work in comments. ("better help sued by" or "Better help pewdiepie" or whatever if you really are seriously interested in facts and not using "PROVIDE SOURCE" as a block card, first link for me at least in both cases)
4:58 For the closest stable orbit around a black hole, it would have to be circular at the speed of light. If the orbit would be elliptical, the speed would vary and would then be once again defined by the orbitals speed max, being the speed of light, while in the remainder of the ellipse it would be lower. Since all matter circling the black hole at similar such distance, it would influence the speed of the matter at the theoretical ISCO, which by all means is a theoretical limit that can't be reached in practical circumstance, due to speed variations by exertion of gravity by the other nearby matter. This can factually even be below the ISCO theoretical limit. Matter circling near the ISCO can attract matter outward, away from the black hole (not by much), and yet, create a gravitational influence that would allow the factual matter in the perfect circle orbit to negate the ISCO's theoretical limit, by an infinitessimal amount though. The theoretical ISCO limit is the one where the orbit is at lightspeed, on an orbital height that requires such, from a said gravitational pull by the black hole's mass. This also means that ISCO's are not constant, and grow or shrink with the black hole's mass shrinking or growing. But, the theoretical ISCO minimum limitation can be an infintessimal smaller, by the matter in orbits near it, outside the ISCO limit (but once again, infinitessimal). Also, the assumption that anything simpy ceases orbital motion and starts falling straight in, is kinda ludicrous. The orbit below the ISCO would deteriorate fast, but be inwards spiral, not a straight line down to the center of mass of the black hole.
14:15 unless I'm missing something, the fit is a big improvement vs the version without the plunging region modelled, but it's not exactly a million miles off from the simple black body approximation.
The only reason I did not press like was the betterhelp sponsorship. They are beyond shady. Lots of other comments surely explain the details better so I'm not even attempting here.
9:55 I kept trying to figure out why I couldn't parse what Becky was saying here and I think it is because the thought wasn't completed in the sentence with the words "because the bigger that region is between the ISCO and the event horizon"
Sunglasses, rent, spoons, tomorrow's homework, all manner of fish, 10mm wrenches, buttons, and the allen key that you need to fix the disposal. And my train of thought.
Guys get over it, she obviously doesn't care Better Help got caught & fined for selling people private sensitive mental health information to 3rd parties. It's 2024 people, money is more important than morals.
1. Does a Black Hole have a "very thick, absolutely not thin (Lack of sufficient internal weak-force interaction)" neutrino-Accretion-disk? 2.could they wobble, ultimately causing Nutation of the jets? 3.which direction(s)? do BHs emit gravitational waves preferentially? N/S or equatorial? if the event horizon vibrates, are there prefered/avoided seismic frequencies? 4. are magnetic field fluctuations, inside of this inbetween region getting compressed and then emitted at the poles at very high photon energies? 5. I like black body radiation, preferably at 24°C, and I Like Hilbert_Einstein's generalLLLreLLativity especially with Kerr icing on Top; it is marvellous, beyond my comprehension.
please stop using better help as a sponsor, their sponsor reads are super triggering. I'm trying to watch a fun video about black holes and suddenly I'm been told about depression and hoplesness, thats just awful
Eh, I don't know of a way around this as far as sponsoring something aiming to promote getting mental health help. Granted, BetterHelp is hot garbage and underpays their therapists along with other problems, but if it were an actual good company, I don't know of better ways to talk about what they do. Coming from someone with chronic depression.
For the "3 measurable properties" - couldn't we still measure those values for different regions surrounding a black hole and see if they're exactly the same everywhere or if there's some variation? technically doesn't that mean there's a lot more we theoretically/hypothetically could measure about a black hole? it's X, Y and Z within a given region of spacetime
Dr. Becky, if the event horizon radius is defined as a region where the **escape velocity** equals light speed, would that not imply that objects could in theory escape from at or even just inside the event horizon, if shot outward at 99.9999999% light speed and then further boosted via some interaction once they've risen above the event horizon? Classical escape velocity is defined as outward speed such that a particle launched from the 'surface' of a massive object at such a speed would fly out away from that object to an infinite distance, reaching zero speed at that infinite distance. Anything slightly less, and the particle would fly out to a very large distance, but then fall back down; anything slightly more, and the particle would fly out to infinity and retain that excess speed even at an infinite distance. If the same classical escape velocity concept applies to the event horizon, then a particle launched from the event horizon at close to escape velocity would fly outward to a great distance, before turning around and falling back. Even a particle launched from just-inside the event horizon, would fly through the event horizon and reach some height above it, before falling back in. Now, if while it is above the horizon, it interacts with something else that gives it an additional boost - or if that particle has a rocket engine attached, and switches on that rocket engine once it's above the event horizon - then that particle could gain enough additional acceleration to escape the black hole completely. This would seem to imply that it's at least theoretically possible for information to escape from inside the event horizon. But is that really the case, or is the very concept of classical "escape velocity" not really applicable in the extremely warped spacetime of the black hole - and my confusion stems merely from misinterpreting or misunderstanding the language used to define the event horizon?
The concept of escape velocity still applies, but, roughly speaking, in General Relativity you can regard space around a gravitating object to be "flowing inward" at the local escape velocity. This means that an object sitting still (relative to the gravitating object) is already moving outward at escape velocity "relative to space" (be careful about using the concept of movement relative to space in other contexts, because it isn't actually a thing, but in this specific context it builds the right intuition to understand what's going on). In non-relativistic contexts, that's fine, to actually escape, you have to move at escape velocity relative to the gravitating object, not relative to space, and there are plenty of ways to do that. But at the event horizon of a black hole, just to stay still relative to the black hole you need to move outward at the speed of light "relative to space", and that's the fastest you can move outward, so you can't actually escape. Another way of looking at it (that doesn't involve the classical concept of escape velocity) is that at the event horizon, there are no directions in spacetime that are both unambiguously forward in time and away from the black hole.
@@JonBrase yeah, that had been my understanding as well - until I noticed for the first time the actual term "escape velocity" being used as part of the event horizon definition; that was a moment when I suddenly felt like I didn't understand anything anymore... You're right, of course: the gravitational "acceleration" at the event horizon isn't a Newtonian quantity, and using the Newtonian concept of "escape velocity" in that context is just flat-out inappropriate! Spacetime is strongly warped there; an object attempting to stand still at the event horizon would actually have to attain (or experience) infinite acceleration, which is of course an impossibility. Now, having read up on this in more detail from expert sources, I'm just mad (not for the first time, either) at sloppy language and misleading terminology being used in the popular exposes of black hole physics... **grrrrrrrr**
@@Spherical_Cow The Newtonian escape velocity formula actually gives the correct escape velocity for GR, it's just that with Newtonian gravity a trajectory that travels faster than the local escape velocity at any point will always escape unless it actually collides with the gravitating object (which, for a point mass, is vanishingly unlikely), regardless of what direction it's headed in initially, whereas in GR, even a point mass (a black hole) will have a set of directions for which escape velocity won't save you, which larger the closer the escape velocity gets to c. At the horizon, only traveling directly outward at c will prevent a collision with the singularity (and it won't properly escape either).
@@JonBrase No, that's the whole point: the Newtonian escape velocity formula is incorrect in the relativistic limit: it only gives the "correct" (to a good approximation) result in the Newtonian limit. The GR version of gravitational acceleration (producing the "force" of gravity) at the event horizon, has extra terms beyond the normal Newtonian ones; it's those extra terms in the equation that completely blow up the Newtonian analogues in the extreme environment near the event horizon. Ignoring those extra non-Newtonian terms produces vastly, horrendously incorrect inferences about black holes: such as that of "escape velocity" being an applicable concept at the event horizon, or such as that of ultra-supermassive black holes (on the order of trillions of solar masses) having an arbitrarily low gravitational acceleration at their event horizons... which is utterly, patently wrong.
@@Spherical_Cow Part of the issue here is that defining acceleration and velocity can be tricky in GR, because time and up/down distances are not the same for all observers. But in Schwarzschild coordinates (the most sensible coordinates for an observer far from the black hole to use), the escape velocity formula is *identical* to the Newtonian formula. The acceleration needed to hover at the horizon is an observer dependent quantity, for the object hovering at the horizon, it's infinite, but external observers see everything happening near the horizon slowed down (infinitely so at the horizon itself), so they actually will observe a finite surface gravity at the horizon.
I'm very dissapointed Dr Becky, you of all people should know the importance of research which you clearly did not do before promoting better help. That or you just don't care 😞 please take accountability for this and at the very least stop accepting their sponsorships.
Dr Becky: I hope you can explain something to me about black holes: If the supernova birthing the blackhole blows away all matter, how can there still be mass in that spot? Ive been taught that matter mass warps spacetime but something isnt adding up...if there is no matter, how can there be mass?
Clearly it doesn’t blow away all matter. It runs out of fuel to keep an equilibrium between inward and outward pressure from burning fuel. At a point where the core of the star can no longer burn fuel, because the material in the core can no longer be made heavier, the outer layers collapse into the core and is bounced back and the remaining material bounced out from the star, and that’s what we see as a supernova. The remaining core which is now super heavy is what ends up as a singularity, black hole.
@@syntaxed2 The fusion leads to matter being turned to heavier and heavier stuff until the core is iron. Iron can’t produce energy, but needs energy, and at that point the fusion stops, resulting in the leftover matter collapsing in on the core, because the pressure is gone. And that leftover matter bounces off the core and that is the supernova. If the core is heavy enough it ends in singularity and that may be what they say is the result in no matter?
GRR!!! Will scientists ever learn that 10% of men have difficulty distinguishing red and green lines in their charts??? I've brought this up at numerous conferences in my field (not astrophysics), and everyone nods and agrees it's a good idea to avoid red and green lines when it's important for their audience to distinguish them, but after 30 years nothing has changed, even though everyone agrees with the idea. Dr. Becky has more influence than I do. Maybe she (or her viewers) could have some influence?
This annoys me as well. No point in showing me nice charts when the lines all look the same colour/indistinguishable to me. Especially as most software now comes with accessibility checking features and employers (including academia) now have to meet legal requirements on accessibility. (My university recently underwent a rebrand and every single colour combination and typeface choice in the new branding was triple-checked for accessibility).
@@reubenmckay That's awesome! I mean your university's consideration of color combinations that can be perceived by nearly everyone. (It's also effective branding.) I never thought of it as an accessibility issue, but I guess it is. The solution is SO simple and it affects so many people. Just use a different crayon! @StevenStyczinski-sy8cj That's one reason the problem persists.
If it was nudged in the ISCO, it could also escape, right? Second, would going faster than light even allow an object to leave a black hole? Once you're inside, there isn't anywhere you can point that leads back outside.
Clarification needed. Matter can escape up to the event horizon but only matter that was not captured into the accretion disk. Example very high speed for example that sent out in pulse in jet away from a Black Hole that approaches the black hole in question near the rotation poles of the black hole where some of this will go direct into the black hole and some will curve towards the black hole but not enough to actually hit the event horizon and thus shoots by the black hole but in a way it can't be captured by accretion disk. Is this correct? I saw another sight not understand the ISCO did not mean all matter inside of that will fall in. It just that something that actually is orbiting up to the ISCO but not inside it will fall into the black hole of it's orbit decays inside the ISCO. The matter orbiting will be made part of accretion disk. Then as the matter orbiting loses momentum it must fall in as it is orbiting.
We need this done on a massive scale. We will get so much information from collecting all the data and doing this with all known black holes. A lot of hard work, but this needs funding.
Dr Mummery mentioned the number of possible x-ray binary stellar size black holes, but what of the supermassive black hole Sagitarius A* at the centre of The Milky Way? Do we lnow its spin and thus something on how it formed?
Is it just me, or has it been quite a while since Dr. Becky last mentioned the theory of supermassive black holes being the result of galaxies merging ? (Honestly, it _might_ be me.)
Question about the spin: I had assumed that the infalling material was first collimated by the accretion disk rather than falling in directly from whatever direction it originated from. Your explanation implies it does indeed fall in from the direction of origin. Is there no collimating then? Trying to answer my own question: no or minimal collimation if there is no or very low spin and hence little or no accretion disk. Is this correct?
Aloha Dr. Becky. So, everything in the universe is "moving" relative to everything else. So too are the black holes. This means they are moving in a specific direction. Does the front edge of their trajectory experience more friction? Ate things gobbled up more from one side than the other side? If so, does that mean the event horizon would kinda be elliptical? Not to a great deal, but it would seem logically there would be. Very curious. Thanks for your time.
@@TwoFoxGibbon Huh? Do you mean the frame of reference centered at the BH? In that frame of reference, the BH is stationary, by definition of the frame of reference. Do you mean, the frame of reference in which the galaxy isn’t moving?
Hey Dr. Becky, if you crossed the event horizon at near the speed of light, would you be able to use the ultra intense gravitational pull inside there to exceed the speed of light. If that gravitational pull is able to keep light inside, the amount of pull should have enough pull to let you get at least the speed of light. As we all know, physics break down once you cross the EH. Maybe the physics inside allow for such speeds.
No, for the same reason that launching an object at 0.5C while traveling at 0.5C doesn't get the thing to 1C. Velocity is never really fully added, instead space and time change to make it always less than the speed of light. I can't remember the exact equation, but it's one where combining two velocities below a maximum always adds to less than that maximum
@@bengoodwin2141 "rapidity", w, adds linearly in special relativity, and: tanh(w) = v/c so your hyperbolic trig identities give the relativistic velocity addition: w'' = w + w' v" = (v + v') / (1 + vv'/c^2)
physics is fine inside the EH, it crashes at the singularity. The problem inside the horizon is curved time: the future is at smaller radii, and the past is at larger radii, so all time-like paths point to the singularity. It's like: say Friday (tomorrow) is the singularity and Wednesday (yesterday) is the horizon. Which way to we point our rocket, even w/ infinite thrust, to avoid Friday and get back to Wednesday?
@@bengoodwin2141 No, that's not quite right: what you say applies only to flat spacetime (as in the context of Special Relativity.) But general relativity creates a weird situation where spacetime itself can move (see e.g. the Lense-Thirring, a.k.a. frame dragging, effect near spinning black holes.) When spacetime itself is moving like a conveyor belt, an object moving near light speed through such spacetime in the same direction, relative to a distant observer, can attain an apparent velocity greater than light speed relative to that observer. (This is a little bit like, if it were really possible to construct a Warp Drive, then one really could travel faster-than-light without breaking the rules of General Relativity.) Of course, in practice the problem is that no light from inside the black hole can reach a distant observer, so in reality the distant observer can't actually observe such apparently superluminal motion of infalling objects.
Excelent video! I have one question, in rotating black holes, ISCO can have two configurations, right? One referring to the orbit in the same direction as the spin and the other in the opposite direction to the spin, right? Wouldn't that affect that information, or at least add a second orbit? Another question, about the previous question: is this stable, or over time all orbits end up decaying to a specific configuration?
However... isn't ISCO outside the ergosphere? Because if in the ergosphere of a rotating black hole the orbits are not stable, doesn't this mean that ISCO is also outside the ergosphere?
Dr Becky this article from live science says Radial migration happens to lots of other stars too. "Roughly half the stars in the solar neighborhood are thought to have been born elsewhere [and been pushed outward]," Debattista said. And the further out from the Milky Way's center, the higher the percentage of stars that have migrated. outward, he added. Are black holes merely the birthplace of suns?
Would have liked to have seen a more in-depth explanation of the innermost stable circular orbit (6GM/c^2 for non-rotating black holes) that didn't conflate it with the marginally bound orbit (4GM/c^2 for non-rotating black holes) and photon sphere (3GM/c^2) for non-rotating black holes. Also should mention that the Kerr effect is different depending upon whether a particle is orbiting in the same direction as the black hole's rotation or opposite, or something in between.
You see something accelerating as it gets closer to the event horizon. Now you have a good idea where it is inside the black shape. Tow black holes merge, but when they touch, the masses are still falling together. When do they actually join into one? Is there a signal at that moment?
If I consider a black hole as a system with ins and outs, ie matter in hawking radiation out, then just knowing the current mass, charge and spin won’t tell you how much matter the black hole has “Processed” into radiation unless you can determine how long the black hole has existed and the typical “processing” rate of matter into radiation. So is there any way to assess how old a black hole may be?
Can you _warp drive_ out of a black hole? I have read that you can get to the Andromeda Galaxy within a week with some special warp drive (I don't remember what it was really called). But because you drive so fast your week is more a year on earth because of time dilation. So I wonder how this would work near a black hole or inside the event horizon.
Pure science fiction. The fabric of space is composed of electrical energy. It's what allows electromagnetic waves to propagate from point A to point B. The universe is flat, meaning the shortest distance is already a straight line. You can't warp energy fields to move matter from A to B. You can however increase the permittivity of space by increasing the amount of electrical energy and decreasing the permeability (other electrical fields). Copper wires vs aluminum wires for instance. But that's strictly electromagnetic waves. For every action, there is an equal and opposite reaction. To accelerate mass forward, you need to accelerate mass backwards.
Looking at the graphic showing the ISCO in relation to spin, the question that leaps to mind is: is it possible for a black hole to spin fast enough such that the ISCO is at or inside the event horizon?
This episode is a primary example of why this channel is so good. I could spend 15-20 minutes reading all the pop-sci articles on a story like this, and would only end up frustrated with pop-sci, and still not really understand what the research was actually saying or why it was important.
In this particular case, the research is extremely interesting to me, and in 21 minutes you presented it extremely clearly and without overdramatizing anything! Thank you so much for the work you put into making these episodes, they are definitely appreciated!!
Maybe she could research her sponsors for at least 1 minute too? Maybe a quick "Google" is prudent before jumping on a "good deal" not to sell out peoples personal information, not providing any actual help. Promoting harmful psycological "help"?
Dr. Becky, please please PLEASE drop BetterHelp as a sponsor. They sell people's medical information to advertisers! 😫
If you can prove this, you can make a HIPAA (HIPPA?) complaint against them. The law is pretty generous here - all you need to do is prove that the company sold its users’ identifying info to third parties. Identifying info can be as simple as a name or an email address - it doesn’t need to be detailed. Feel free to ask me more about this law - I used to work in healthcare.
So does everyone else. If you don't want your info sold DO NOT use a online therapy platform. If your desire for a therapist overweighs your concern about data use, then use Betterhelp or other online therapy platform.
@@tomkelley4119 They have literally been fined by the US FTC for it.
@@tomkelley4119 they already got a 7.8 million dollar fine for it
@@tomkelley4119 They have been fined for it. This is not a new thing.
DROP Betterhelp!
You people need to stop. lol
@@wizarddragon yeah let's support the billion dollar health company that sells patient data lol
@@wizarddragon At least they are people.
My local NHS had me do Better Help
CBT. Was free to me, but also useless 😅
It’s meant literally for me to be targeted
Ditto on dropping the BetterHelp sponsorships. It is disappointing that some of the best quality, well-explained science content on this site is invaded by marketing for a company that has consistently shown itself to be untrustworthy regarding their patients’ private health data and also the treatment of their care providers.
I'm surprised, I really thought she had dropped it after the last video got comments just like this one. That last video took me to the vlogger who just read out all the gory details of their past lawsuit. Absolutely insane
Orwell says it's either Black Holes, or therapy. You must choose. I won't repeat what Freud said. 😂😂
@@yrobtsvt contractual agreements are pretty hard to get out of when you're busy
@@yrobtsvt especially when you live in the uk. I was stuck with a vodaphone contract I didn't have access to the account to. I couldn't even close the account when I went into branch with ID. I had to let the contract go unpaid and wait until the debt got bought out by local solicitors
@@yrobtsvt She might have a contract :-(
Panic! At the ISCO
LOL!
Brilliant
:D yeah, Or Isco Inferno .. (1976)
👏👏👏👏
🕺🏼💃🕺🏼💃
Omg such a good joke 😂😂😂😂
Please drop BetterHelp as a sponsor! They lied to patients about selling personal information to advertisors.
Unexpected Mapmen appearance at 8:05. I didn’t know Dr. Becky could be even more awesome!
Map men map men map map map men men. 😊
Haha! Came here in the comment section to write exactly this!
I'll have to look into these map men, since Dr Becky fans approve
@@OrafuDa ...men.
Oh the cut away to mapmen, awesome🎉🎉
Please rethink your sponsorship! "BetterHelp has agreed to pay $7.8 million in a settlement agreement with the U.S. Federal Trade Commission (FTC) over allegations of misusing and sharing consumer health data for advertising purposes."
Even though this video aimed to explain a very specific thing, it's one of the best summaries I've seen to explain what the different regions are around a black hole. It would be perfect if it also explained that the black circle we see (the shadow of the black hole) isn't actually the event horizon even though it's the image we choose to show whenever we mention the event horizon
Stop using better help as a sponsor. Just look at the problems closely. It’s very weird watching a TH-camr who seems to be disconnected from TH-cam.
I finished A Brief History of Black Holes yesterday. Fantastic book, thank you Dr B!
I absolutely loved it ❤
What did Hawking say about the particle theory of Gravity? I haven't read it yet.
A Brief History of *Time* is by Hawking, A Brief History of Black Holes is by Dr Becky- though I would assume she probably discussed Hawking’s theories in the book, the similar titles make me think you confused the two
@@stevenkirkwood7039 Particles can't escape the interior, period. So to would be the actual force of gravity. Gravitons.
Do Quarks inside a black hole multiply as their bonds are ripped apart by the insane gravity?
Map Men Cameo - Excellent. Black hole spin measurement - even better.
Aw cmon, not BetterHelp *again* ! They're way too shady to be trusted. Please Becky, don't keep them as sponsors !
I know, seeing her continue to accept their sponsorships is incredibly disappointing and I'll likely unsubscribe if she doesn't take accountability for it.
Wasn't the hole thing against BetterHelp that... it just hasn't worked for some people? Like every other form of therapy?? At least that's what I read / heard a while back. Don't know if there's new stuff out against them.
@@JordiVanderwaal No, the thing against betterhelp was selling the therapy details of their clients to whoever offered enough money.
@@JordiVanderwaal They sold patient data to advertisers. They have a dubious record of checking credentials of the people they hire and a long, detailed history of substandard care for patients. It is significantly more than 'not working for some people'.
@@JordiVanderwaal They were accused of sharing their clients personal info with Facebook - don’t know if that was proven, though…
I'd love to see a side project where you have scientists explain what is on their blackboard in the background of interviews! And, do any of them just doodle up the blackboard for the interview, to mess with us?
Do Quarks inside a black hole multiply as their bonds are ripped apart by the insane gravity?
Your episodes about black holes are the best. You are even more excited than in your other videos, it's contagious. Thank you, Dr. Becky.
naw, she's a galaxy girl.
I think it's her area of expertise.
Anton Petrov covered this, but to get the scoop from the lead author, who works down the hall from Dr. Becky, WOW!
Anton Petrov is a click baiter and a sensationalist. I would not follow him.
@@Kivikeskuperhaps, but with 100% less betterhelp....
Seriously, though, I recognize that Anton isn't a scientist like Dr. Becky, but he seems like an earnest enthusiast and I like hearing what interests him.
@@Kivikesku he always put links to scientific papers that he is describing in his videos and he also always mentions it(links to peer review papers) so how does that amounts to click baiting and sensationalism in your mind is beyond me but I'm sure you'll put some proof of that accusation. Even Becky (not just her but many other science educators) is following and liking Anton because he is humble, sincere and great science educator.
@@robydee920 It's his video titles.
love astrophysics, going on to do it at uni. it makes me so happy to find a place where astrophysics can be explained without any arguments, thanks Becky :)
fancy that i just ate some uni at a jap sushi restaurant i did 🐳
Stop advertising for scams please.
They're one of the highest paying youtube sponsors at present, because it turns out that scamming people with mental health issues is wildly profitable.
Becky you should be ashamed of yourself. Unsubscribed.
She may not know about not everyone is so involved on YT news and drama etc..
@@rushyscoper1651people have been telling her in the comments for some time now
Contracts are a hell of a thing huh? I am sure she wont take another sponsorship from them in the future.
@@mrdwets8952 If what you say is true, that's pretty simple to deal with. First ad after you learn of a problem "I'm required by a contract I deeply regret signing to tell you the following." That's neutral to the product so it doesn't violate any clauses meant to protect them from being called out, it doesn't say anything that could be sued over, but it does make it clear she's not espousing her own opinion.
I hope somewhere out there, a black hole researcher publishes a paper titled "Panic! at the ISCO"
Better help is shady. Don't promote them.
What are the good stories behind this company?
Are there any companies that are sponsors of yt videos that aren't shady?
VPN, supplements, privacy... They all have a stink.
Just don't throw any money at them
Hey, Dr. Becky, do you think you hit more than 50% "STOP SHILLING FOR BETTERHELP" comments yet?
She must be stuck in a contract.
@@stargazer7644 If she is contractually bound to making a certain number of ads, it would give everyone a lot more peace of mind if she said so in a community post.
id return the dirty money
For once I’ve finally read a paper before dr Becky covered it so I got to listen to her clear explanation to test what I got from the paper! Thank you Dr Becky!
Betterhelp ad means I'm not watching this video, nor any further video until the issue is remedied. Choosing sponsors ethically is important.
I'm sorry Dr. Becky, your content is informative and amazing, but I had to dislike for the BetterHelp sponsorship. I'd tell my story about my really bad experience that reflects a large number of other testimonies from their users and therapists alike, but honestly today I'm just so tired. Mental health struggle is real, and people absolutely need to be able to seek out help for it, but BH is demonstrably not it.
Thanks!
Thanks. I did General Relativity based on Steven Weinberg's book in 1982. I never did any "application" of this work to astronomical observations. Great to learn about this after 40-odd years ....
Yes, l agree with some comments, stop with the Better Help ads. They only exist to make money. As most people.
Mass Charge and Spin makes it sound like its just a really really big quark.
einstien tried to model particles as tiny singularities, I think. The math didn't work out
quarks also have color (but not really), flavor and weak hyper charge or weak isospin--pick 1.
I think it sounds like we have absolutely no idea what we're talking about. I think it sounds like we're tweaking the math to fit the model. With ignorant words being touted as variables like dark matter and dark energy. It seems like we have black holes in our math. The age of the universe sure went out the window with the James Webb telescope. I wonder how much money we've spent looking for dark matter? How many brilliant students could we have put through school? The answer is in humanity but we don't invest anything in that. The picture of the black hole is a complete lie. There's so many variables in that you could have made a Mickey Mouse picture.
When you get down to it the matter inside a BH isn't a thing, it's some kind of inversion of "thingness" lumped over an intersect that defines the point that matter was a thing at ..before mass just kept pushing toward it and broke something.
@@luke144 Obviously there's a lot of stuff in our theories that don't work, but some findings match our predictions, so it's likely that our current theories are at least close to the truth, even if they aren't complete. We shouldn't pretend that we really understand what's going on, but that doesn't mean that we know literally nothing either.
Dr. Becky, despite not understanding most of what you presented, I still enjoy it as it convinces me of how much I don't know. Bottom line is, black holes win!
With all that singing always in the bloopers Dr. Becky should just make a second channel with song covers.
I would watch it!
That channel would likely get lot of copyright strikes.
Agreed, she has a great singing voice and I usually only get snippets of it in the bloopers
And she could adjust some lyrics of songs to fit astrophysics better and be free of copyrights through parody law (at least in the US, not sure about international law on that)
If Doctor Becky has written any a full length physics filks I'd love to hear them. But what we see in the bloopers is the kind of thing I do all day at work singing a
phrase that's on my mind (a customer's name I've just on a label, or whatever) and then free-associating another line or two of lyrics 'til I run dry. Very few of this "microfilks" ever get written down let alone developed into full songs; They're just created in the moment to be enjoyed in the moment, and then they're done.
It took me a bit to understand why the ISCO would be closer the faster the spin. You didn't explain that frame dragging affects the process and I had forgotten about it. Black holes can really be counterintuitive at times. Thank you for the video.
4:07 Technically there do exist trajectories within the ISCO that escape to infinity, it's just that trajectories that don't eventually either fall in or escape don't exist in that region.
Chiming in with the others, better help is a well-known trap. The only service they reliably provide is reducing bank balances.
Dr Becky Question: If two blackholes were positively changed would they repell each other?
I belive so, it's used in a concept for using microscopic black holes to make a very efficient battery. Purely hypothetical of course 😂
Sure, but significant charge on a black hole would probably not last long. A positively-charged black hole would very strongly attract electrons, which would quickly neutralize the charge.
@@michaelsommers2356 "very strongly attract *any* *_free_* electrons" FTFY.
I am so thankful for Dr. Becky. ♥
Dr Becky, I appreciate the work you do to promote sound science in an understandable way to the public. You're one of my favourite channels. ...BUT the continued sponorships from Better Help need to be addressed before more and more of us leave. You aren't just promoting an unethical company. You're also ruining your own credibility.
I notice that no one complaining about this company has offered any evidence against them. Just accusations. Nor have I seen any of the complainers offering any financial support to this channel. Talk about lack of credibility.
@@michaelsommers2356 maybe you should read the news more and TH-cam comments less. It's right there for you to learn, you choose not to because it's not spoon fed to you?
I dont think she's ruining her credibility as an astrophysicist, but I do want her to stop promoting betterhelp
@@davidlange1000yeah she was still a great astrophysicist but she's losing the " trust " of people for advertising the scam
@@michaelsommers2356 Just accusations hm? Zero documented evidence of wrongdoing? No leaks? No controversies? No sketchy data selling/correlation?
1. Click the TH-cam Search input field.
2. Fill in "betterhelp" and press enter, or see the suggested search terms.
3. Scroll past the BetterHelp sponsored first 3 (or so) entries, if you dare to step out of your comfort zone.
It’s great that Einstein’s theories are constantly being validated, but after all of these years no one should be all that astonished that they hold up.
Honestly thinking of black holes, habitable planets, Space all give me hope because it means everybody were all worth something and our job is to become interstellar and reach higher consciousness to reach out full potential as human beings or homo sapiens sapien.
that pitch for better help was wild...
Chi square improvement from 353.05 vs 352.34 is "massively improved" (@ timestamp 14:15). What defines massively?
The improvement mentioned is relative to the chi^2 of 1173.12, so the very first model.
As for the massively, I am assuming the second, whole number listed behind the / are the degrees of freedom (d.o.f.), basically how many data points you have minus the number of parameters of your model. If your model describes the data well, the chi^2 will be around that number. If you get a chi^2 value significantly larger than the number of degrees of freedom, that usually means your model is not good. If you get a chi^2 value much smaller, this usually means you overestimated the errorbars on your data.
Black hole question I've been having trouble finding an answer to; if time dilatation increases exponentially towards infinity as you approach the event horizon, wouldn't the black hole evapourate ahead of you as you got sufficiently close to the event horizon? They have a finite lifespan, so I don't think you could ever cross into it.
Well, in retrospect I suppose you would cross it, but not by falling on, but because the black hole will grow more before it shrinks, and so the event horizon would probably rise to meet and then envelope you, and then space/time role reversal or other weirdness may mean that it doesn't immediately(from your point of view) overrun you in the other direction? I dunno.
Though black holes are usually depicted as a a two dimensional hole, or three dimensional in the sense of a whirlpool shape, they're actually three dimensional "holes" right? I.e. you can fall directly into them from any direction. If that's the case, is the accretion disk a disk? Because of the spin?
It is a sphere, not a hole.
I think because of the spinning, yes, similar to how it is with the planets in the solar system being mostly in the same plane.
No it's for the same reason galaxy tend to be 2d or any solar system.
If u have stuff moving in 3d orbiting each other they tend to unite in one plane over time that would include the center spin unless something interfere with it. Cause if u think about it that the direction of all the gas and stuff united to before a star or planet formed would became the direction of spin for the object.
Thanks for the replies! Follow up....does the accretion disk spin independently of the black hole, or black sphere, and when we say a black hole/sphere spins, what exactly is spinning?
@@scottbadger4107 The spin axis of accretion disks are not all aligned with the black hole spin axis due to things like precession of the black hole, magnetic fields or the angular momentum of the material that formed the accretion disk.
Spacetime is spinning, or twisting around. The spinning of space (frame-dragging, an effect due to general relativity) has been detected around Earth, and black holes drag space around themselves in an extreme way. The simplistic view of a non-spinning black hole is unlikely to happen in nature since the gas or star that collapsed to form the black hole would most likely have been spinning, since angular momentum is conserved. An accretion disk is also formed due to angular momentum of the matter around the black hole, and the spin rate is also increased by the flow (frame-dragging) of spacetime around the black hole.
Yes, please drop BetterHelp as a sponsor. Thank you!
Hello Dr. Becky. So nice this video. Congrats to Dr. mummery!
Are you planning on doing a video on the evolution of supermassive black holes ft. Professor Hickox? Please say yes!!! 🙏🙏🙏🙏
Thank you in advance and best regards!!
Not betterhelp 😢
I have few stupid/strange questions:
* If BH have charge, is BH a monopole or a dipole?
* Is it possible to theoretically spin up a black hole?
* if a BH gets high rotation does the shape changes, if so if rotation is high enough can it change shape into torus, or brake apart from the angular momentum?
* would such a breakup look like... big bang?
Thanks for all the solid facts and sciences!! 🎉
7:17 Matter that gos into a black hole ceases to be discrete, and also can't fission.
The only thing happening in a black hole that has any high degree of chance to exist,
is fusion, which happens with most all matter that enters it. It creates an element
which atomic number would be written similar to 1E+100 (arbitrary large number).
Despite the instability under less gravity for such a large element to exist is undone
by the gravity preventing fission, since fission needs space, while the gravity
denies this space to exist inside the mass of the black hole. You can't split apart
if there's no room to split into. Much like 1 m3 of water can't divide into two separate
parts if only 1 m3 of volume exists.
Matter being compressed inside a black hole is being compressed into even smaller
volumes than that of a neutron star.
GAAA WHY ARE YOU STILL DOING BETTER HELP ADS ?!?!?
They are very publicly proven to not provide what they advertise. So many people have been vocal about their experiences it’s surprising you either don’t know or don’t care.
There are myriad other businesses you can do ads for and I hope they only continue on your channel because of a contract.
Ill keep checking back and probably keep feeling uncomfortable at the better help ads and tuning out when I see them.
Great shout-out for back holes! I never miss your episodes which really explain things so well that I, with an old biologist's maths (non)skills can get the picture without reading the papers. So, sorry BetterHelp, I don't need counseling to keep thinking about black holes and matters such as ' - - - whether pigs have wings' (apologies to Charles Dodgson) after Dr Becky explains it!
i thought you had finally dropped betterhelp, pretty disappointed...
I don't see you providing any financial support to the channel.
@@michaelsommers2356
You have no idea if they are supporting her in any other way.
@@Elora445 I see very few people contributing via the Thanks button, and there is no Patreon or similar. What other way is there?
@@michaelsommers2356
Maybe they are one of the few, then?
Fascinating! Thanks, dr. Becky! 😃
Stay safe there with your family! 🖖😊
Hitherto I've yet to used hitherto in a sentence.
Love the videos!
Not any more.
Mass. Determined by how other objects behave near it
Electric Charge - Voltage. The amplitude (squared?) of the EM field. How do you determine this from a billion light years away?
Spin - spin is rotational momentum (potential?), momentum is energy, energy is mass, mass curves ST, a black holes spin contributes to its mass. How is this measured vs mass?
Conclusion: The EM field is independent of the curvature of spacetime if we can some how measure or deduce the electric charge of a black hole. Wrong? Right?
Let's not do BetterHelp, eh?
If someone needs help, they should look for a professional, not a damn app.
Question: What would happen if the spin was so strong the ISCO went beyond the event horizon? Or is that not possible, I don’t see why it wouldn’t be, would it be a way to explore inside the event horizon? Also wouldn’t that mean the “black” part of the black hole is more bright then it should be since the Isco goes beyond the horizon effectively reducing the size of the event horizon?
How can you promote BetterHelp's brand? I wouldn't want to be associated with them if I could help it
She might not know. I didn't until very recently. Hopefully she'll notice all the comments on this video and do some research.
@@samdoehart1333 Why don't those complaining about the company ever cite any actual evidence?
@@michaelsommers2356 Oh yes, I'm sure the $7.8 million they were fined by the FTC last year for selling patient health information to advertisers, which is a violation of federal law, was completely groundless.
@@michaelsommers2356 Maybe you have heard about Google? Posting links don´t work in comments. ("better help sued by" or "Better help pewdiepie" or whatever if you really are seriously interested in facts and not using "PROVIDE SOURCE" as a block card, first link for me at least in both cases)
4:58 For the closest stable orbit around a black hole, it would have to be circular at
the speed of light. If the orbit would be elliptical, the speed would vary and would then be
once again defined by the orbitals speed max, being the speed of light, while in the remainder
of the ellipse it would be lower.
Since all matter circling the black hole at similar such distance, it would influence the speed
of the matter at the theoretical ISCO, which by all means is a theoretical limit that can't be
reached in practical circumstance, due to speed variations by exertion of gravity by the other nearby matter.
This can factually even be below the ISCO theoretical limit.
Matter circling near the ISCO can attract matter outward, away from the black hole (not by much),
and yet, create a gravitational influence that would allow the factual matter in the perfect circle
orbit to negate the ISCO's theoretical limit, by an infinitessimal amount though.
The theoretical ISCO limit is the one where the orbit is at lightspeed, on an orbital height that requires such,
from a said gravitational pull by the black hole's mass.
This also means that ISCO's are not constant, and grow or shrink with the black hole's mass shrinking or growing.
But, the theoretical ISCO minimum limitation can be an infintessimal smaller, by the matter
in orbits near it, outside the ISCO limit (but once again, infinitessimal).
Also, the assumption that anything simpy ceases orbital motion and starts falling straight in, is kinda ludicrous.
The orbit below the ISCO would deteriorate fast, but be inwards spiral, not a straight line down to the center
of mass of the black hole.
If a black hole became a point in space time, there would be no spin.
14:15 unless I'm missing something, the fit is a big improvement vs the version without the plunging region modelled, but it's not exactly a million miles off from the simple black body approximation.
The only reason I did not press like was the betterhelp sponsorship. They are beyond shady. Lots of other comments surely explain the details better so I'm not even attempting here.
9:55 I kept trying to figure out why I couldn't parse what Becky was saying here and I think it is because the thought wasn't completed in the sentence with the words "because the bigger that region is between the ISCO and the event horizon"
We can be certain that some portion of a black hole's mass consists of unpaired socks.
Sunglasses, rent, spoons, tomorrow's homework, all manner of fish, 10mm wrenches, buttons, and the allen key that you need to fix the disposal.
And my train of thought.
The other sock of the pair has been emitted as Hawking radiation.
@@jamesdriscoll_tmp1515 Also pens, pencils and guitar picks.
Dr. Becky, you are such a charming communicator; I really enjoy your videos.
Dr Becky! Off the shoulder look...
Guys get over it, she obviously doesn't care Better Help got caught & fined for selling people private sensitive mental health information to 3rd parties. It's 2024 people, money is more important than morals.
1. Does a Black Hole have a "very thick, absolutely not thin (Lack of sufficient internal weak-force interaction)" neutrino-Accretion-disk? 2.could they wobble, ultimately causing Nutation of the jets? 3.which direction(s)? do BHs emit gravitational waves preferentially? N/S or equatorial? if the event horizon vibrates, are there prefered/avoided seismic frequencies? 4. are magnetic field fluctuations, inside of this inbetween region getting compressed and then emitted at the poles at very high photon energies?
5. I like black body radiation, preferably at 24°C, and I Like Hilbert_Einstein's generalLLLreLLativity especially with Kerr icing on Top; it is marvellous, beyond my comprehension.
please stop using better help as a sponsor, their sponsor reads are super triggering. I'm trying to watch a fun video about black holes and suddenly I'm been told about depression and hoplesness, thats just awful
They are also a pretty shady company
Eh, I don't know of a way around this as far as sponsoring something aiming to promote getting mental health help. Granted, BetterHelp is hot garbage and underpays their therapists along with other problems, but if it were an actual good company, I don't know of better ways to talk about what they do. Coming from someone with chronic depression.
You can just skip ahead, past the add. It's not that hard :v takes just a few seconds
Grow up
For the "3 measurable properties" - couldn't we still measure those values for different regions surrounding a black hole and see if they're exactly the same everywhere or if there's some variation?
technically doesn't that mean there's a lot more we theoretically/hypothetically could measure about a black hole?
it's X, Y and Z within a given region of spacetime
Dr. Becky, if the event horizon radius is defined as a region where the **escape velocity** equals light speed, would that not imply that objects could in theory escape from at or even just inside the event horizon, if shot outward at 99.9999999% light speed and then further boosted via some interaction once they've risen above the event horizon?
Classical escape velocity is defined as outward speed such that a particle launched from the 'surface' of a massive object at such a speed would fly out away from that object to an infinite distance, reaching zero speed at that infinite distance. Anything slightly less, and the particle would fly out to a very large distance, but then fall back down; anything slightly more, and the particle would fly out to infinity and retain that excess speed even at an infinite distance.
If the same classical escape velocity concept applies to the event horizon, then a particle launched from the event horizon at close to escape velocity would fly outward to a great distance, before turning around and falling back. Even a particle launched from just-inside the event horizon, would fly through the event horizon and reach some height above it, before falling back in. Now, if while it is above the horizon, it interacts with something else that gives it an additional boost - or if that particle has a rocket engine attached, and switches on that rocket engine once it's above the event horizon - then that particle could gain enough additional acceleration to escape the black hole completely. This would seem to imply that it's at least theoretically possible for information to escape from inside the event horizon. But is that really the case, or is the very concept of classical "escape velocity" not really applicable in the extremely warped spacetime of the black hole - and my confusion stems merely from misinterpreting or misunderstanding the language used to define the event horizon?
The concept of escape velocity still applies, but, roughly speaking, in General Relativity you can regard space around a gravitating object to be "flowing inward" at the local escape velocity. This means that an object sitting still (relative to the gravitating object) is already moving outward at escape velocity "relative to space" (be careful about using the concept of movement relative to space in other contexts, because it isn't actually a thing, but in this specific context it builds the right intuition to understand what's going on). In non-relativistic contexts, that's fine, to actually escape, you have to move at escape velocity relative to the gravitating object, not relative to space, and there are plenty of ways to do that. But at the event horizon of a black hole, just to stay still relative to the black hole you need to move outward at the speed of light "relative to space", and that's the fastest you can move outward, so you can't actually escape.
Another way of looking at it (that doesn't involve the classical concept of escape velocity) is that at the event horizon, there are no directions in spacetime that are both unambiguously forward in time and away from the black hole.
@@JonBrase yeah, that had been my understanding as well - until I noticed for the first time the actual term "escape velocity" being used as part of the event horizon definition; that was a moment when I suddenly felt like I didn't understand anything anymore...
You're right, of course: the gravitational "acceleration" at the event horizon isn't a Newtonian quantity, and using the Newtonian concept of "escape velocity" in that context is just flat-out inappropriate! Spacetime is strongly warped there; an object attempting to stand still at the event horizon would actually have to attain (or experience) infinite acceleration, which is of course an impossibility. Now, having read up on this in more detail from expert sources, I'm just mad (not for the first time, either) at sloppy language and misleading terminology being used in the popular exposes of black hole physics... **grrrrrrrr**
@@Spherical_Cow The Newtonian escape velocity formula actually gives the correct escape velocity for GR, it's just that with Newtonian gravity a trajectory that travels faster than the local escape velocity at any point will always escape unless it actually collides with the gravitating object (which, for a point mass, is vanishingly unlikely), regardless of what direction it's headed in initially, whereas in GR, even a point mass (a black hole) will have a set of directions for which escape velocity won't save you, which larger the closer the escape velocity gets to c. At the horizon, only traveling directly outward at c will prevent a collision with the singularity (and it won't properly escape either).
@@JonBrase No, that's the whole point: the Newtonian escape velocity formula is incorrect in the relativistic limit: it only gives the "correct" (to a good approximation) result in the Newtonian limit. The GR version of gravitational acceleration (producing the "force" of gravity) at the event horizon, has extra terms beyond the normal Newtonian ones; it's those extra terms in the equation that completely blow up the Newtonian analogues in the extreme environment near the event horizon.
Ignoring those extra non-Newtonian terms produces vastly, horrendously incorrect inferences about black holes: such as that of "escape velocity" being an applicable concept at the event horizon, or such as that of ultra-supermassive black holes (on the order of trillions of solar masses) having an arbitrarily low gravitational acceleration at their event horizons... which is utterly, patently wrong.
@@Spherical_Cow Part of the issue here is that defining acceleration and velocity can be tricky in GR, because time and up/down distances are not the same for all observers. But in Schwarzschild coordinates (the most sensible coordinates for an observer far from the black hole to use), the escape velocity formula is *identical* to the Newtonian formula. The acceleration needed to hover at the horizon is an observer dependent quantity, for the object hovering at the horizon, it's infinite, but external observers see everything happening near the horizon slowed down (infinitely so at the horizon itself), so they actually will observe a finite surface gravity at the horizon.
I'm very dissapointed Dr Becky, you of all people should know the importance of research which you clearly did not do before promoting better help. That or you just don't care 😞 please take accountability for this and at the very least stop accepting their sponsorships.
She's been ignoring these comments for months and months now. There is no possible way she does not know about them.
@@vonwuxNo, if you support something that I think is bad then you are either evil or misinformed, duh
@@MrMctastics Nothing at all to do with _thinking_ they are bad. It's well documented and not remotely difficult to find information on.
@@vonwuxI would guess it's likely that she has some kind of contract and isn't allowed to stop taking their sponsorships or talk about this.
@@bengoodwin2141 Unless she signed a contract for over a year without doing any research, that is simply not the case.
really cool paper. you explained it really well. Great video! Its so cool that you work with the guy who’s research is making all the news
Stopped watching the video as soon as the BetterHelp add came out… you are a scientist… do some research on your sponsors before accepting them…
Dr Becky: I hope you can explain something to me about black holes: If the supernova birthing the blackhole blows away all matter, how can there still be mass in that spot?
Ive been taught that matter mass warps spacetime but something isnt adding up...if there is no matter, how can there be mass?
Clearly it doesn’t blow away all matter. It runs out of fuel to keep an equilibrium between inward and outward pressure from burning fuel. At a point where the core of the star can no longer burn fuel, because the material in the core can no longer be made heavier, the outer layers collapse into the core and is bounced back and the remaining material bounced out from the star, and that’s what we see as a supernova.
The remaining core which is now super heavy is what ends up as a singularity, black hole.
@@mikaelbiilmann6826 But Leonard Susskind and Kip Thorne have said there is no matter left...
@@syntaxed2 The fusion leads to matter being turned to heavier and heavier stuff until the core is iron.
Iron can’t produce energy, but needs energy, and at that point the fusion stops, resulting in the leftover matter collapsing in on the core, because the pressure is gone. And that leftover matter bounces off the core and that is the supernova.
If the core is heavy enough it ends in singularity and that may be what they say is the result in no matter?
GRR!!! Will scientists ever learn that 10% of men have difficulty distinguishing red and green lines in their charts??? I've brought this up at numerous conferences in my field (not astrophysics), and everyone nods and agrees it's a good idea to avoid red and green lines when it's important for their audience to distinguish them, but after 30 years nothing has changed, even though everyone agrees with the idea.
Dr. Becky has more influence than I do. Maybe she (or her viewers) could have some influence?
90% of men don’t see that as a big issue!
This annoys me as well. No point in showing me nice charts when the lines all look the same colour/indistinguishable to me. Especially as most software now comes with accessibility checking features and employers (including academia) now have to meet legal requirements on accessibility. (My university recently underwent a rebrand and every single colour combination and typeface choice in the new branding was triple-checked for accessibility).
Astronomers are worse at making plots than they are at naming things.
It's 8 percent and banning red and green from charts would make them worse for 92% of men.
@@reubenmckay That's awesome! I mean your university's consideration of color combinations that can be perceived by nearly everyone. (It's also effective branding.) I never thought of it as an accessibility issue, but I guess it is. The solution is SO simple and it affects so many people. Just use a different crayon!
@StevenStyczinski-sy8cj That's one reason the problem persists.
If it was nudged in the ISCO, it could also escape, right?
Second, would going faster than light even allow an object to leave a black hole? Once you're inside, there isn't anywhere you can point that leads back outside.
interesting content, disliked for the sponsor tho
Clarification needed. Matter can escape up to the event horizon but only matter that was not captured into the accretion disk. Example very high speed for example that sent out in pulse in jet away from a Black Hole that approaches the black hole in question near the rotation poles of the black hole where some of this will go direct into the black hole and some will curve towards the black hole but not enough to actually hit the event horizon and thus shoots by the black hole but in a way it can't be captured by accretion disk. Is this correct? I saw another sight not understand the ISCO did not mean all matter inside of that will fall in. It just that something that actually is orbiting up to the ISCO but not inside it will fall into the black hole of it's orbit decays inside the ISCO. The matter orbiting will be made part of accretion disk. Then as the matter orbiting loses momentum it must fall in as it is orbiting.
MAP MEN! MAP MEN! MAP MEN!
MAP MAP MAP MEN!
We need this done on a massive scale.
We will get so much information from collecting all the data and doing this with all known black holes.
A lot of hard work, but this needs funding.
Sorry Dr. Becky, any time I see BetterHelp, I click off. By felicia.
Dr Mummery mentioned the number of possible x-ray binary stellar size black holes, but what of the supermassive black hole Sagitarius A* at the centre of The Milky Way? Do we lnow its spin and thus something on how it formed?
Is it just me, or has it been quite a while since Dr. Becky last mentioned the theory of supermassive black holes being the result of galaxies merging ? (Honestly, it _might_ be me.)
dislike for this sponsor, not the content
Question about the spin: I had assumed that the infalling material was first collimated by the accretion disk rather than falling in directly from whatever direction it originated from. Your explanation implies it does indeed fall in from the direction of origin. Is there no collimating then? Trying to answer my own question: no or minimal collimation if there is no or very low spin and hence little or no accretion disk. Is this correct?
Aloha Dr. Becky. So, everything in the universe is "moving" relative to everything else. So too are the black holes. This means they are moving in a specific direction. Does the front edge of their trajectory experience more friction? Ate things gobbled up more from one side than the other side? If so, does that mean the event horizon would kinda be elliptical? Not to a great deal, but it would seem logically there would be. Very curious.
Thanks for your time.
Moving in a specific direction... in what reference frame?
@@drdca8263 In the frame of reference to its position located within a galaxy.
@@TwoFoxGibbon Huh?
Do you mean the frame of reference centered at the BH? In that frame of reference, the BH is stationary, by definition of the frame of reference.
Do you mean, the frame of reference in which the galaxy isn’t moving?
@@drdca8263 Are you Dr. Becky?
@@TwoFoxGibbon I am not Dr. Becky. Why do you ask?
Hey Dr. Becky, if you crossed the event horizon at near the speed of light, would you be able to use the ultra intense gravitational pull inside there to exceed the speed of light. If that gravitational pull is able to keep light inside, the amount of pull should have enough pull to let you get at least the speed of light. As we all know, physics break down once you cross the EH. Maybe the physics inside allow for such speeds.
No, for the same reason that launching an object at 0.5C while traveling at 0.5C doesn't get the thing to 1C. Velocity is never really fully added, instead space and time change to make it always less than the speed of light. I can't remember the exact equation, but it's one where combining two velocities below a maximum always adds to less than that maximum
@@bengoodwin2141 "rapidity", w, adds linearly in special relativity, and:
tanh(w) = v/c
so your hyperbolic trig identities give the relativistic velocity addition:
w'' = w + w'
v" = (v + v') / (1 + vv'/c^2)
physics is fine inside the EH, it crashes at the singularity. The problem inside the horizon is curved time: the future is at smaller radii, and the past is at larger radii, so all time-like paths point to the singularity. It's like: say Friday (tomorrow) is the singularity and Wednesday (yesterday) is the horizon. Which way to we point our rocket, even w/ infinite thrust, to avoid Friday and get back to Wednesday?
@@bengoodwin2141 No, that's not quite right: what you say applies only to flat spacetime (as in the context of Special Relativity.) But general relativity creates a weird situation where spacetime itself can move (see e.g. the Lense-Thirring, a.k.a. frame dragging, effect near spinning black holes.) When spacetime itself is moving like a conveyor belt, an object moving near light speed through such spacetime in the same direction, relative to a distant observer, can attain an apparent velocity greater than light speed relative to that observer. (This is a little bit like, if it were really possible to construct a Warp Drive, then one really could travel faster-than-light without breaking the rules of General Relativity.) Of course, in practice the problem is that no light from inside the black hole can reach a distant observer, so in reality the distant observer can't actually observe such apparently superluminal motion of infalling objects.
@@DrDeuteron yeah, that looks a bit like what I learned.
Excelent video! I have one question, in rotating black holes, ISCO can have two configurations, right? One referring to the orbit in the same direction as the spin and the other in the opposite direction to the spin, right? Wouldn't that affect that information, or at least add a second orbit?
Another question, about the previous question: is this stable, or over time all orbits end up decaying to a specific configuration?
@@quantum_relativity Ohh, I didn't know that! Thank you for the explanation! 🥰
However... isn't ISCO outside the ergosphere? Because if in the ergosphere of a rotating black hole the orbits are not stable, doesn't this mean that ISCO is also outside the ergosphere?
@@quantum_relativity thx again for the explanation! 🥰
Eww. Ad skip...3:40
Thank you!!! i hate better help with a passion
@@jaybennet4491 You should look into an English tutor.
You should do more interviews. I know it's probably a lot of work if they aren't just down the hall, but you are very good at it.
Dr Becky this article from live science says Radial migration happens to lots of other stars too. "Roughly half the stars in the solar neighborhood are thought to have been born elsewhere [and been pushed outward]," Debattista said. And the further out from the Milky Way's center, the higher the percentage of stars that have migrated. outward, he added. Are black holes merely the birthplace of suns?
Would have liked to have seen a more in-depth explanation of the innermost stable circular orbit (6GM/c^2 for non-rotating black holes) that didn't conflate it with the marginally bound orbit (4GM/c^2 for non-rotating black holes) and photon sphere (3GM/c^2) for non-rotating black holes. Also should mention that the Kerr effect is different depending upon whether a particle is orbiting in the same direction as the black hole's rotation or opposite, or something in between.
You see something accelerating as it gets closer to the event horizon. Now you have a good idea where it is inside the black shape. Tow black holes merge, but when they touch, the masses are still falling together. When do they actually join into one? Is there a signal at that moment?
If I consider a black hole as a system with ins and outs, ie matter in hawking radiation out, then just knowing the current mass, charge and spin won’t tell you how much matter the black hole has “Processed” into radiation unless you can determine how long the black hole has existed and the typical “processing” rate of matter into radiation. So is there any way to assess how old a black hole may be?
Very well explained, thank you.
Can you _warp drive_ out of a black hole?
I have read that you can get to the Andromeda Galaxy within a week with some special warp drive (I don't remember what it was really called). But because you drive so fast your week is more a year on earth because of time dilation. So I wonder how this would work near a black hole or inside the event horizon.
Pure science fiction. The fabric of space is composed of electrical energy. It's what allows electromagnetic waves to propagate from point A to point B.
The universe is flat, meaning the shortest distance is already a straight line. You can't warp energy fields to move matter from A to B. You can however increase the permittivity of space by increasing the amount of electrical energy and decreasing the permeability (other electrical fields). Copper wires vs aluminum wires for instance. But that's strictly electromagnetic waves.
For every action, there is an equal and opposite reaction. To accelerate mass forward, you need to accelerate mass backwards.
For the first time since I've been watching I actually DID hear a siren when you felt you had to stop because of a siren!
Innermost stable orbit for light is always 1.5 times EH, right? Why then is innermost stable orbit for matter depending on spin?
Looking at the graphic showing the ISCO in relation to spin, the question that leaps to mind is: is it possible for a black hole to spin fast enough such that the ISCO is at or inside the event horizon?
No, that’s when it’s at its maximum spin, because matter at the event horizon needs to be moving at the speed of light in its orbit
Is the ISCO different for objects that are spinning in the same vs opposite direction of the black hole?
I agree Black Holes ARE the most fascinating thing to study in astrophysics and having your channel and passion for black holes is quite a treat.