Black holes might be dark stars with layers: New solution found

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Do black holes even exist? You might think the evidence is overwhelming. But in a new paper, physicists have shown that Einstein's theory of space-time allows another option, it's that black holes might be layers of shells with dark energy inside. I had a look, and here's what I learned.
Paper here: iopscience.iop.org/article/10...
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#science #sciencenews #physics

[@FourOf92000]

do physicists think singularities _exist,_ or is it more an "our math is messed up but we don't know how to fix it yet" marker?

[@SabineHossenfelder]

I don't know any physicist who thinks that singularities are physically real. Then again that doesn't mean those physicists don't exist!

[@VikingTeddy]

Most scientists don't really believe in a singularity. But any guess as to the size and composition of the object (if any) within would be a guess, so they don't talk about it. All they know for sure is "this is what the math says".

[@francoislacombe9071]

I'm pretty sure that whenever singularities appear in a model, that model is either wrong, or incomplete, or both.

[@PlanetEarth3141]

​@@VikingTeddy If math proved it we wouldn't be asking questions. Thinking humanity knows any math is as insane as a pig flying. Logically any math we depend on that doesn't support all math means we don't know any math or that there is no math. Math is a human invention like all we do. Humanity can not prove any knowledge isn't flawed or represents reality.

[@Llortnerof]

That's kinda the problem. We don't know which it is.

[@lucianomoffatt2672]

Depicting the physicists addicted to finding solutions of Einstein equations as cats eating some herbs is stunning.

[@SabineHossenfelder]

creativity inspired by limitations of stock footage is an underappreciated phenomenon

[@PlanetEarth3141]

​@@SabineHossenfelder It's the seizure of unsound minds.

[@louisrobertson9215]

😂😂

[@mcnaugha]

I’ve been saying for a while now that “solving Einstein’s equations” is nothing but video games by another name. The whole lot of it is video gaming and idea popularity contests. None of it reality. It is a shame the publications of these leads so many to proverbial war against one another’s beliefs… like history repeating itself, again and again. So, much of it so conveniently unfalsifiable… at least not within our own lifetime. As such, there is never anything truly risked.

[@hugegamer5988]

It’s catnip. It’s cannabis for cats.

[@mihan2d]

Doctor: Wide Sabine does not exist, she can't hurt you Meanwhile wide Sabine: 👁️ 👄 👁️

[@Broockle]

It's us who become wide relative to Sabine as she passes the event horizon 😆

[@AnujFalcon]

@@Broockle Age old 'frame of reference' issue. Good one.

[@michaelwinter742]

Beware “wide not” counter-Sabine

[@marcoottina654]

I laughed mute then I would never admit

[@MichaelOfRohan]

Hahaha wow an actually funny comment 💪🌏🫸 🦵🦵

[@deathsinger1192]

1:37 stuff like this is why I love this channel

[@ponyote]

Hearing Sabine say "prof" is the highlight here. Publish or perish is such a thing. Thanks for getting us the real facts. Knowing is half the battle. Brilliant may be the other half.

[@alexrocks00000]

Sabine, I just wanted to say that in your ad read, when you mentioned how much probability you had forgotten, that really warmed my heart. Sometimes it's embarrassing to feel proficient in a field (for me, Biostatistics) and to realize how much of another field you have forgotten. If a smart person like you can forget stuff, then maybe there's hope for the rest of us!

[@Farming-Technology]

Agreed. Every time I learn someone's name; I worry I'll forget how to tie my shoelaces. 😮😅

[@neglesaks]

You might be surprised how often that PhDs and Professors have to look up formulae in thei compendiums. We're human, not machines.

[@xmuzel]

I forgor 💀

[@margodphd]

With increasingly narrow specialties, the path to becoming an expert is inevitably going to include a lot of forgetting. It's only human, y'know? Now, if we could control whether we forget Something Important that will Inevitably Come Up or That Embarrassing Preschool Situation...

[@joshua43214]

This is a good thing (fellow biomathematician here). I could not get rid of the mind poison of probability fast enough once I graduated.

[@user-jr6bl9ih3e]

Thank you, Sabine, for making the fine subtle point that there's a difference between things that could exist according to the solutions to Einstein's equations and things that actually exist. I might that add that for things to actually exist, there must be a physically allowed process or series of steps to arrive at that final state, it's not enough for the final state not to violate the laws of physics to actually exist.

[@whiteeye3453]

Like there isn't proof that gravitational waves exist

[@olbluelips]

@@whiteeye3453there isn’t proof that any physical object exists. Doesn’t mean there isn’t evidence for it

[@whiteeye3453]

@@olbluelips and evidence is ither fake or hoax

[@olbluelips]

@@whiteeye3453 and what's your worldview, exactly

[@whiteeye3453]

@@olbluelips no gravitational waves don't exist

[@dasstigma]

"Disappointingly Human" is a new favourite of mine.

[@Thomas-gk42]

hihi

[@greatPretender79]

Agreed! Will use frequently.

[@Thomas-gk42]

@@greatPretender79 We need a collection of Sabine´s "best of"

[@Rudxain]

It feels like something Glados would say

[@Walter-Montalvo]

Sabine: Black Holes = Hotel California

[@Notsogoodguitarguy]

Welcome to Hotel Blackholifornia

[@sjzara]

They break the laws of physics so that wine becomes a spirit.

[@anuragb.9349]

You can check in anytime you like but you may never leave...

[@vincentkinequon4631]

Did the " scientists " even consider the notion that nothing can enter a black hole. Surely someone has, they didn't just assume that Matter falls into a black hole do they? I can go on and on. Did the inflationary hot big bang really happen as we think it did. And ultimately, are our finest thinkers going down endless rabbit holes that may take them exactly to where they started. Like I said "on and on". But anyway, I love science and the conceptions of these wonderful people, whether right or wrong. 😊

[@Spiegelradtransformation]

A lot of talk noone knows!

[@Notsogoodguitarguy]

So, our math professor gave us an example of how math can be used to calculate the "real world", but if one isn't careful with where limits are placed and so on, then you get things that are mathematically correct, but has nothing to do with reality. His example was with derivatives concerning car breaks. They could simulate how the car would behave while breaking by...I've forgotten already, it's been like 6 years, but, basically, the car's speed would start approaching zero, then dip bellow zero, then back over, and oscillate like that until it approaches zero (imagine a sinus wave, but slowly converging to zero, that's how the graph looked like). And his student presented the graph to him proudly, cause it was apparently a tough calculation. The professor looked at it and then asked - "If you step on the breaks while driving, do you start rocking back and forth until you stop completely?" Is it possible that something like this is happening here as well? There's a mathematically sound solution with these gravistars that doesn't actually conform to reality? Like the "mathematically correct" solutions to warp drives that require negative energy densities and more power than the entire universe can generate?

[@zinken255]

If you step on the breaks while driving, do you start rocking back and forth until you stop completely? No, not at the start, but possibly at the end, at least for the occupants.

[@Notsogoodguitarguy]

@@zinken255 hehe

[@garethdean6382]

Yes, that's correct; the solution is stable,like a pencil balanced perfectly on its point, but there's no real way to produce it naturally. It could exist,if you could magically make it, but we don't know HOW it might be made. Whereas 'regular' black holes will just happen.

[@blogattacker]

I just love the cool names they come with: gravastars

[@TheRABIDdude]

Sounds like a gravy brand

[@suicune2001]

@@TheRABIDdude I was thinking more like Space Jam.

[@Mikaci_the_Grand_Duke]

"👏👏👏 Sabine, what are you doing!?" 😂

[@MCsCreations]

Fascinating stuff indeed! Thanks, Sabine! 😃 Stay safe there with your family! 🖖😊

[@gregjones2217]

Thank you sharing such an interesting concept. Certainly worth thinking about. We have so much to learn.

[@pineapplepizzasandwich1974]

I never imagined I would get to experience a Sabine & Flextape crossover but I am glad I did.

[@stuartschaffner9744]

You have an episode from two months ago, explaining Kerr's new paper, which I suspect answers many of the questions raised here. First, in practice, there are no known black holes with zero angular momentum. Not only is it difficult in practice to get mass to stop rotating completely but also quantum mechanics implies that the ground state of any particle having angular momentum is nonzero. If I understand correctly, Kerr's paper suggests that angular momentum turns the Schwarzschild point of singularity into a ring. Matter tends to follow toroidal paths that take forever in proper time to approach the singularity. I never specialized in any of this, so I can't say much more useful.

[@Ken-1]

That is how I understood it. Importantly, he suggests that the centrifugal throw of rotating black holes can counteract the pull of gravity within their event horizon, potentially creating an inner region where matter and light are free to move almost normally (thus avoiding the supposed "ring singularity"). That's the interesting region. Perhaps said gravastar (or a baby universe even) could exist within it. I do like this more sensible approach to explaining black holes

[@Posesso]

Really loved the speed ticket joke

[@isaacyonemoto]

Isn't it the case that the analysis of gravitational waves uses statistical methods and filters that are trained on our expectation of black hole mergers and we'd have to redo analysis from raw data against a gravastar statistical model to really be sure?

[@garethdean6382]

Sort of. To find merger candidates data is filtered to look for the 'chirp' expected of a merger, a signal rising in intensity and frequency that appears at both LIGO detectors at the right time. In this way only merger signals that fit the general pattern of what we expect will be processed,something which can be said to be limiting. On the other hand a lot of work has been done on identifying any other signals present, for novel processes and to try and find ways to eliminate noise. So we know we're not missing any significant weird signals. The LIGO detections require gravitational wave emission from two inspiralling dense masses,but not necessarily black holes.(For example we have at least one neutron star merger on record.) So we should be able to identify mergers of things that are like, but not black holes. We can also predict what signal other kinds of merger would produce and check LIGO data for that. Which is what's been done with the gravistar model; there's a big enough discrepancy there that we know LIGO should detect it and it shouldn't resemble a black hole merger. The difference is just too great.

[@davestorm6718]

I would say yes, though, I doubt resources will be spent to study anything that strays this far from the main stream.

[@j-jlevy]

Once more, as the rest of all of your posts, loved it.

[@nusu5331]

Awesome as always! Saw you interview with the philosophy show from the swiss. Would love , if you would do a special series, where you dig deeper into the questions about whats the matter of the universe, does free will exist and all that. Maybe you could even interview other scientists too.

[@Sandysand701]

I've always thought a black hole is named for its appearance, not for what it actually is, there is no doubt the gravity culminates from a huge amount of trapped material, so no way is it a porthole to another dimension/realm. Actually you could say It's behavior is the opposite of a star, a star emits energy, a black hole consumes it, for all we know the colour of a black hole could be Ultraviolet or Grey, unfortunately the gravity will never let us see, I think a black mass would be a better description.

[@j.f.christ8421]

John Mitchell was the bloke who first thought of black holes (way back in 1783), and he called them dark stars. Reading his wiki he also thought up the balance used in the Cavendish experiment. Also into earthquakes & magnets, smart dude.

[@reddragon7030]

Ok but what if.. they’re not stars, but superatoms

[@JJEMTT]

👀

[@mahshshsrklingfa7031]

Or cheesecake

[@reddragon7030]

No.. as is they have less in common with stars, and more in common with atoms. Follow electron shell theory, and the event that strong force collapses space.

[@TheRABIDdude]

I think you just described a neutron star my dude.

[@reddragon7030]

I mean.. you could be correct! The theory came from stacking matter (theoretically) over and over until you collapse the electron shell, and then searching for a comparable observation. At some point the object gets so dense photons do not emit, and what would you call that? Note* KZbin wiped my first attempt to respond

[@JeffACornell]

Could this be extended to a continuous solution? Instead of nested shells of matter, each right where an event horizon would normally form, you could have a continuous distribution of matter that's right at the edge of forming an event horizon at every point within itself. If increasing the number of nested shells improves the stability, would this type of continuous distribution be perfectly stable?

[@xavierdemerson1913]

Your videos are delightful and amazing Good job !

[@rustychilders7231]

I have no formal education on any of this. I always thought since the universe started in a super dense state, black holes were just returning to that state. Maybe the stars that collapsed were formed of larger chunks that didn't become stable enough. Simplistic I know.

[@Mike-yt4jq]

OH wow. This is so interesting to me right now . I've been very interested in gravity among many other things lately. Your videos are superb. Thanks Sabine!🤓🙏✨️

[@icaleinns6233]

Loved the Eagles reference! Well done!!!

[@mashw]

Very cool. Reminds me of the models of rotating black holes which have a doughnut shaped ergosphere and an inner event horizon, PBS Space Time did an episode a couple years ago on this.

[@mikeward9870]

Check out anytime. Since it takes forever to hit the center, perhaps Rovelli is right, when it gets down to a quantum squeeze size, perhaps it bounces back out?

[@gonzaloperez5787]

Hello Sabina, as always, your videos are very interesting. Could you someday talk about the theory that suggests black holes could actually be quark stars? It's proposed that after the level of gravity resistance of neutrons, there could be another level of nuclear resistance in quarks. Regards

[@Overt_Erre]

FINALLY Sabine touched on my favorite black hole theory!

[@TheIgnoramus]

Wonder-full times 😂🎉 your videos have just been getting better. I can see the bottle-neck opening, this year is gonna be wild!

[@hamishfox]

I love the humor in these videos. The cats with the catnip was just *chef's kiss*

[@askquestionstrythings]

I like the idea your Proff gave of making two predictions, one for the thing and one for the exact opposite. This complies with how I view a similar idea in statistics where you make a hypothesis (a thing is a thing) and a "Null" Hypothisis (a thing is not a thing). I feel testing an idea and the exact opposite of that idea helps lead to evidence for and against the idea.

[@zblackrider]

Sabine always with the fun.

[@_andrewvia]

I enjoyed the humor in this video. Thank you!

[@EROSNERdesign]

Great stuff. More please.

[@gristlevonraben]

always a great video! and funny! and wise.

[@SB5SimulationsFerroviairesEEP]

Thank You! Stéph.

[@jimparry2743]

Sabine, I have been watching your excellent videos for years and I love them (however, that doesn't necessarily mean I understand them). I have noticed recently, that you appear to have developed an English sense of humour - Bravo!! Is this something you've always had or is it part of your ongoing 'development' as a brilliant content creator? Kind regards, Jim - England x

[@RollcageTV]

Are those gravastar layers *turtle* shells? I mean, it could be turtles all the way down 🐢.

[@khuti007]

I had a "prof" grade 7 science teacher like that, he had great answers but i never found out what they were. As soon as I asked a question, I always had the leave the class, sit outside and stare into space. Thats why i like it so much.

[@delphinazizumbo8674]

"It's full of stars." --David Bowman, about to get shredded

[@Jeewanu216]

Ms. Sabine, I was wondering if you'd heard of the recent statement from Kerr regarding the singularity issue and any thoughts you might have. Love the work ♡

[@_zoinks2554]

Sabine, I went to the Black Forest to visit my ancestral village but in fact it is a very green place. I demand an explanation for this!

[@starman2337]

I've always pictured black holes as shells of frozen time. Objects seen falling toward the horizon approach light speed, so appear shorter in the direction of travel and are never seen to cross. As they approach c, length becomes zero and forms a shell, preserving information about it at the EH surface. Frozen time prevents a singularity as viewed from the outside Universe. The increased mass means the horizen moves a tiny bit away from the center for the next shell. When the black hole evaporates, information in those shells imprints on the Hawking radiation, preserving it.

[@aadilnaqvi4399]

That's quite neat.

[@krox477]

What is time??

[@starman2337]

@@krox477 I think I know what time is until someone asks me to explain it. Then I know not.

[@starman2337]

@@aadilnaqvi4399 And since time in the outside Universe goes by increasingly faster near the EH from the infalling object's point of view, the black hole evaporates before it has a chance to reach the center to form a singularity.

[@johnjameson6751]

When something is uncertain or unknown, I think it is good science to consider and idea and its opposite, and make contrary predictions based on each.

[@bjrnhjortshjandersen1286]

You are quite inspiring...not always totally easy to follow but still...🙂

[@D_Ding0]

Thanks for the great explanation! You’re funny, I love it ❤

[@felipemarques2015]

Greiner's Field Quantization is my favourite introductory book about Quantum Field Theory

[@JAAB9296]

What a great channel !

[@simonzinc-trumpetharris852]

I remember first hearing about gravastars several years ago. And MECO's. You need to do a vid about these too.

[@nox5282]

Sabine I’m not a physicist but I am doing thought experiments of timeless physics and now I have a promising result that has potential unify physics, specifically cosmology with quantum mechanics and statistical mechanics. I was able to show how conservation of energy emerges from very simple fundamental principles. What do I do now? Do I self learn deeper until I’m at the level of a master degree? Or do I reach out to someone who can help me develop this proper? My idea shows how universe can manifest physically from a conceptual space, it shows how the universe got its boundaries etc. It all started by reimagining gravity as the least action through a mass-energy field

[@nigeldepledge3790]

I'm so glad that you pointed out that the singularity in a black hole is a purely mathematical entity. If the Schwarzchild solution is correct, we can never know what is at the centre of a black hole. Of course, I have to acknowledge that the Schwarzchild solution is for a non-rotating black hole, which almost certainly cannot exist unless someone finds a way to break the conservation of angular momentum.

[@ELXABER]

The final stage of a black hole's evaporation, depending on its initial size, could leave behind either a tiny black hole or a stable, dense object resembling a "dark star". Suppose a quark star or neutron star is in the center of a 'Black Hole' with special matter (Infinite compression is not decided by zero) and particle-antiparticle pairs near the Event Horizon. In that case, one particle falls In, and the other escapes. If the negative energy particle escapes, then the laws of energy and matter conservation are resolved. Also, the resulting mass from the 'Dark Star' or dead star which has an evaporation leaving a dead star, could account for some of the lost mass attributed to dark matter. Dark energy, or the dark particle escape from the 'Black Hole', accounts for some of the 'Dark Energy' and would probably be stronger nearer a 'Black Hole.'. I think if we can find the remnants of a 'Black Hole' or dead star with extreme density mass, we could work backward from that.

[@AB608052]

I think I came up with something like this years ago. I wonder if it's similar. I said in large dense objects like a planetary core, if the thermal pressure overwhelmed gravitational pressure, there could be a relaxation through the inducement of a quantum state, primarily lowering the energy via degeneracy... it was a pretty approximate idea, kind of a Linus Pauling. I had put it out on Twitter, I wonder if it was annoying because it was smart or stupid. I'm just a chemist

[@AB608052]

Right, and the # of quantum states would increase as you went closer to the center. Layers maybe.

[@starventure]

Ah, but what of the old "what would happen if I fell to the center of the earth?" problem? If the center of ANY mass is where gravitation is cancelled out by the surroundings, should not a black hole obey the same laws? Instead of a singularity at the center, a near singularity as a shell around the center with either normal matter(super high elements?) or absolutely nothing?

[@AB608052]

It's been a long time since I thought about this, and I'm not a physicist, but I think you did a perfect 180 @@starventure

[@AB608052]

Actually, that might be a quantum mechanics with gravity in it. Hey, maybe you're the smartest man in the world@@starventure

[@starventure]

@@AB608052 The power of alcohol...

[@JohnSmithoriginal1]

You have the best science channel on All of Youbtube. Respect on your name !.

[@edcorns3964]

I had professor (quite famous in IEEE circles) who used to say that forgetting the old is as much important as learning the new. His argument was that there's only so much space available in our heads for all the things that we keep crammed in there, so one has to forget something old to be able to learn something new. I agree with that assessment of his, but it turns out that he was right in more ways than just that one. People, especially scientists, tend to get stuck on what they "know" (assume to be true), and that makes them increasingly rigid (over time), and (eventually) unable to learn anything new. I guess this is just another way of saying what Max Planck expressed so long ago -- science does indeed advance one funeral at a time, as those who "know" the old (assume it to be true) either abandon their (wrong) "knowledge" (which doesn't happen that often) or die (of old age, which, thankfully, happens quite regularly), freeing some space (in the collective human mind) for the new to replace the (now-forgotten) old. I think that this problem of getting stuck on the old (pretty much always) stems from not learning how to deal with self-importance first (and it's cardinal rule to learn that very thing first), as those who do not learn how to keep their self-importance in check tend to fall prey to the cost sunk fallacy. In other words, having invested so much of their time and energy into something that has already taken a big chunk of their lives, they (practically always) have trouble letting go of that which is "obviously wrong" (that is, obviously wrong to everybody else but them). Anyway, this dance between forgetting the old and learning the new is one of the main reasons why scientific breakthroughs usually (when they don't happen by pure accident) come from outsiders to the field. Einstein was a perfect example thereof... but he, himself, did eventually fall into the same trap of refusing to let go of what he "knew" (assumed to be true), and then ended up trying to fit his perfectly-crafted round peg (of a theory) into the square hole (of reality) for the rest of his life. Having recognized that trap myself, I like to avoid it by occasionally "forgetting" (putting aside) everything I "know" (assume to be true), and then amuse myself by coming up with all kinds of "crazy" models of reality (that still fit all of the observations of that reality). I guess that's why I still haven't completely ruled out the simulation hypothesis (which is indeed very hard to rule out, and that's what makes it so appealing even to some physicists out there). I have, however, realized that simulation hypothesis is a non-problem to begin with (to genuinely inquiring minds), because any hardware that this (presumed) simulation would be run on would have to exist in a universe that's just as mathematical as this one. That other (presumable) universe might have different rules (laws of physics) than this one, but I've also concluded that all possible mathematical models can always be mapped to each other. In other words, for any two mathematical models (or mathematical universes), there will always exist a mapping function (also mathematical, obviously) between them... which, if you are following my logic, means that all mathematical universes are fundamentally (that is, generally, if not in exact details) equivalent. What this means is that the only real difference between any two forms of... existence (as to not limit ourselves with the term 'universe') is in whether they are finite (in at least one aspect) or infinite (in all of their aspects). This existence that we're all sharing right now is obviously finite in at least one aspect (otherwise, quantization of anything in it would be impossible), and this finite existence is, therefore, fundamentally equivalent to any other finite existence (that may or may not exist out there), and fundamentally different from any infinite existence (at least one of which must exist out there), which is what makes the simulation hypothesis such a non-problem to begin with. But, I'm now digressing, and moving too far away from the subject of this video. Star-within-a-star-within-a-star-within... huh? I can't imagine how that would work (in practice), but I'm always intrigued by any fractal (self-resembling) structures. This universe is undoubtedly fractal in nature, but that aspect of it would be the consequence of the fact that this universe is being... generated (for the lack of a better word) from "simple" (nothing simple about it) recursive (self-referencing, mathematical) rules. I now wonder what the limit of this star-within-a-star-within... etc. model would be. Singularity at the center of it all (which would defeat the whole purpose of the model, namely, trying to avoid black holes and their singularities)? Or an empty (holographic) sphere of some "volume" (that is, occupying certain region of space of certain volume), but with no actual space inside of that sphere? Those would be the only two options (that I can think of) for a black hole as well, so... what exactly is this model bringing to the table (that's actually new)? I guess... it would solve the problem of needing extra (never observed) dimensions of space(time) if you could have a black-hole-within-a-black-hole-within... etc. (if it works for stars, it must work for black holes, too) in just 4 dimensions. In other words, it seems to me that this model (using only 4 dimensions for its fractal structure, by decreasing the size of the structure in each iteration) is (mathematically) equivalent to a model that uses hyperdimensional space and then embeds (in that hyperdimensional space) the same (that is, mathematically equivalent) fractal structure by increasing the number of dimensions by 1 in each iteration. Then again, if one started with infinitely divisible space (which is [mathematically] equivalent to having infinite number of dimensions to work with), any finite number of dimensions could be constructed out of that (infinitely divisible) space, and no one existing inside of those (finite) dimensions would ever be able to detect all those (infinitely many) other "dimensions" (which aren't really dimensions, it's just how mathematics sees them), so having any finite number of (whether observable or not) dimensions in a physical model is... a non-problem to begin with. Hmm... In any case, there are certainly some interesting ideas in this model, regardless of whether the model itself has any correlation with (this, physical) reality or not.

[@YummyFoodOnlyPlz]

It seems like you think the new is always more good and correct, the old that got forgotten should righteously disappear. That's an extremely dangerous bias to hold. Nature doesn't care about the chronological order of the gained knowledge and insights.

[@markmcclain4342]

I recently learned what the “nothing can escape a black hole not even light” means. It’s the escape velocity that is greater than the speed of light and since matter can’t travel faster than light is unable to ever get past that high escape velocity. That’s a big point I didn’t understand. But past the event horizon if you had some way to travel faster than light, you could possibly escape. That’s a bit exotic and I think probably not possible but I like the idea.

[@sapelesteve]

Interesting video Sabine. What I want to know is what separates the layers in these so called dark stars? 🤔🤔

[@ravinsaber]

Wide Sabine is going to give me nightmares 😭 excellent video as always 💜

[@henriksundt7148]

There's no better place to grow your knowledge than Brilliant? Not true! Stay scientific, dear Sabine.

[@adnan7698]

Great. They took out the coolest 2 things about a black hole, event horizon and singularity. This is why we can't have nice things

[@djackson603]

Sabine, does this mean that black holes are behaving as atoms do? Exhibiting properties similar to the electron shells and the nuclear shell model?

[@adamgibbons4262]

Please do a video on plasma cosmology and the electric universe theory. I would love to hear your thoughts on these topics

[@esecallum]

Not allowed . It's forbidden. Even the work electric is forbidden

[@PietroSperonidiFenizio]

Sabine knowledge for its own sake is not bad. A lot of math was developed before we knew what was it for. Think topology or non Euclidean geometry and so on. I think it's fascinating that you can find gravestar inside others. Now if someone had a question for you where should it go?

[@luislopez-tx4tl]

coming from a math background this is so interesting. i have hard time narrowing down my question, how do scientists and physicists know when the math is too good to be true

[@NICMULBERRY]

Very very very very very very INTERESTING!!!

[@MrHichammohsen1]

Finally some sense in black hole research.

[@JonBrase]

From EHT observations, the exterior of GR black hole solutions has been tested to decently high precision. However, a significant bit of discomfort I have with black holes is that the interior of GR black hole solutions is an untestable prediction, so I'm inclined to believe that the existence of black holes with GR-conforming interiors is as much an article of faith as any of the alternatives. Eventually near-horizon effects should let us determine if there are exterior deviations from GR, though, but depending on how close the QG corrections to GR are to the Planck scale, we may, for any given black hole, have to wait for approximately one evaporation timescale before any differences are observable.

[@Ausiguy1]

Sabine, would you mind doing a video to explain the following to us like we're 5 years old. Here is the thought experiment: 1. Let's say we have a star or mass that is slowly gaining additional mass by consuming nearby planets and/or stars 2. As it gains mass it's density and gravitational force increases and it's diameter would either grow or shrink (please explain which is correct) 3. At some point it's gravity reaches the point at which light passing close by would be refracted (lensing) 4. Then the gravity reaches a point where light from the surface can no longer escape 5. At this point it's still just a mass that is still just absorbing masses that get drawn into it 6. So effectively this is what's referred to as a black whole, but underneath the event horizon it's just a large mass with large density and gravity 7. There should be nothing that dramatic occurring that would all of a sudden reduce the inner mass to a singularity where all the mass just magically disappears 8. So isn't this a simple explanation for how black holes form and what they consist of? Again, please explain why not like we're 5 years old. Thanks so much. Peter

[@garethdean6382]

There's a whole bunch of problems with this. A minor problem is that as a star gains mass it increases its fusion rate, its temperature and thus the outward force of radiation and matter. Larger stars resist adding more mass, above about 100 sun's worth a star can't grow larger feeding on gas. Above about 300-500 sun masses it's actively ejecting entire sun's worth of mass as a powerful solar wind. (Incidentally this means that more massive stars get larger, not smaller as they gain mass, but their cores get smaller and more dense.) The major problem is that as more mass is added, objects in the star must move faster to avoid compressing. A star so massive that light cannot leave its surface will have particles just under its surface that need to move faster than light to avoid collapse; no matter can do that without having more than infinite energy. So all the particles in the star will be too slow to avoid collapse and will all collapse inwards forever. Creating a 'traditional' black hole. Before this though there are other processes that will kick in. Core-collapse Supernovae happen when a star's core gets too heavy and collapses, forming a black hole or neutron star,Type1a supernovae happen when a white dwarf gets too massive and instantly fuses,vanishing in a blast of energy. Pair-instability supernovae happen when a star's core gets too hot, creates antimatter and collapses. We've even seen a few neutron star mergers, where two neutron stars collide, fracture and form a black hole with the release of a massive blast of energy and heavy elements.

[@danielh.9010]

I'm not able to give a simple answer. However, there are classical examples in astrophysics where matter accretion occurs, e.g. en.wikipedia.org/wiki/White_dwarf#Binary_stars_and_novae . About the conditions for the creation of a black hole see en.wikipedia.org/wiki/Black_hole#Gravitational_collapse . About question 2: That's difficult to answer and depends on which object we're talking about. For example, en.wikipedia.org/wiki/Stellar_evolution#White_and_black_dwarfs states that higher-mass white dwarfs have a smaller radius than lower-mass ones. About question 3: Light is always "refracted" by gravity. It's just that the effect is normally so small that it's barely observable. But stars are massive enough to cause measurable gravitational lensing. And black holes even more so. About question 4: At that point a black hole has already formed. Matter always undergoes gravitational collapse, and if there is no physical process that is able to generate enough pressure to stop the gravitational collapse, then it will collapse into a black hole / singularity. Typically, in stars the process that generates the pressure to stabilize the star is the fusion reaction inside the star. Once that fusion reaction fizzles out the star quickly collapses. If during that collapse it becomes dense and hot enough to allow fusion of heavier elements then that fusion process will halt the collapse until the fusion reaction fizzles out again, and so on. In the end the star's core collapses either into a white dwarf or a black hole or something more exotic (e.g. neutron star), depending on the mass. If at some point an event horizon forms (i.e. light can't escape) then the black hole has already formed and the matter inside of it is quickly collapsing into a singularity. About question 6: For all we know that mass is concentrated into a singularity. The mass limit at which matter collapses into a black hole is the Tolman-Oppenheimer-Volkoff limit, and is somewhere between 2 and 3 solar masses. About question 7: Wrong, see 6. Also, the mass doesn't disappear. It's part of the singularity. We don't know any laws of physics that would prevent the mass from quickly collapsing into a singularity. We just expect that there are unknown laws that prevent if from being concentrated into a point.

[@danielh.9010]

By the way: here is high-quality animation of the visual effects while falling into a black hole: kzbin.info/www/bejne/aqO3p2ytq9uUqpo . Yes, the event horizon is not "magical" and the laws of physics still work normally inside of it.

[@Scubadooper]

I would suggest a gravastar forms due to the curvature of space time at the event horizon preventing bosons from communicating force in the direction out of the gravastar leading to the quantum foam becoming fractionally dimensioned, e.g. 2.5D 2D plus "in". A bit like Apollonian sphere. I'd also suggest the quantum foam could be responsible for the "random" aspect of gravity in Oppenheim's post quantum gravity model (that seems to negate the need for dark matter or dark energy)

[@linuxophile]

One of the few things we can learn from history is that if there is a mathematical solution of gr then it exists somewhere. Iirc schwarzschild solution was initially discarded on the basis of being unphysical

[@EinsteinsHair]

It was unphysical. Schwarzschild was solving for a non-rotating star. Of course it had an infinity at the center, but even Newton's equation had that infinity, but we knew all of the mass of a planet or star was not actually at the center, so we knew this was unphysical. Einstein and Schwarzschild noticed the odd radius, but since most of a star's mass would be outside the radius, clearly it was some sort of mathematical artifact. Neither of them proposed that there could be a new type of object where all of the mass was inside the radius.

[@vilefly]

This got me thinking on whether or not black holes can have particle shells just like atoms have electron shells. The outermost shell behind the event horizon would have to be photons, the next possible electrons, and so forth, based on the mass/energy levels of said particles. It just might be very orderly instead of chaotic, with exception of the accretion disk.

[@Spherical_Cow]

Not possible, because gravitational acceleration inside the event horizon exceeds light speed (precisely at the event horizon the gravitational acceleration exactly equals light speed: this is what defines the event horizon to begin with). Thus, inside the black hole, any photon or particle would need to move faster than light (in a direction away from the singularity) just to remain stationary. Since nothing can move faster than light, everything that crosses the event horizon thus inexorably falls down into the singularity.

[@vilefly]

@@Spherical_Cow guess I should have said outside the event horizon instead of inside.

[@idontknowwhatahandleisohwell]

love this

[@davidelliott5843]

Everything has a singularity if you squash it enough. An object big enough to rip stars apart does not need to be infinitely small. It simply(?) needs to be dense enough for its gravity to trap light.

[@nugget6635]

The best explanation I have is that a Black Hole is the next step of Neutron Star in terms of density... The more dense a star gets the smaller it is. (Neutron star is smaller than Earth and white dwarf is Earth sized). Therefore the Black Hole is probably a dot.

[@mojoneko8303]

Once you scientists get this all figured out I'm sure you will be the first to let us know. Looking forward to that video if I live that long. Thanks for the video!

[@Hovercraftltd]

Shells, sounds like an idea in the right direction, in that if gravity has polarity all regular moons, planets, stars indeed all globes and 'black holes' are massive shells with all the action in the protected interior habitat.

[@MrPapamaci88]

Uhm, what is the name of the following theory? I'll describe it. This theory is where black holes are just simply empty shells of ultra-dense matter and light and pretty much everything that can get stuck on them because everything stops due to time dilation at not the event horizon but where time is at a stand-still (or just infinitely slowed) and that's also the reason why black holes can grow by bloating up as a bubble of empty void since it's the shell that grows. The shell itself has a shared gravitational point at the center (like celestial objects of similar mass in binary systems orbit each other around a point and not one or the other) where the gravity of the shell concentrates but also this point has no mass, nothing that would stop it from acting like a singularity, it's just a pure shared gravitational field. Again, an empty shell can also spin as well as orbit around that point at its center. It is similar to the holographic theory which suggests that black holes have all the information plastered on their event horizon but what I'm saying is everything is literally just plastered on the time-stop shell if you will. This is the most simplistic view I can think of on black holes and I would like to know if anyone is actually pursuing this idea.

[@BastilsBlather818]

Hey right on, cool video😊

[@lucdombar4527]

"The fact that it's an answer to the equation doesn't mean it actually exist" But does that mean that it might be able to exist, even if it doesn't happend naturally? (In an artificial/experimental setting for exemple?) I guess it could also show that there is some constraints missing?

[@tinu5779]

To me it always sounds like: Star -> collapse -> magic -> singularity. But what is the magic? Since time slows down the smaller and heavier the "thing" becomes will it ever reach point zero? Or will it just become infinitely slow and never form a singularity?

[@woobilicious.]

Somethings that bothers me about the typical blackhole model (and I'm no expert, so wouldn't mind having someone correct me if I'm wrong) is that we say someone falling in to a black hole, especially a super massive one, wouldn't really notice they're falling it, but there's two things they *would* see, and that's time-dilation causing both the light coming from the universe to blueshift, and hawking radiation to also "blue shift". That someone falling in to the blackhole would never enter it within the lift-time of the external universe, so the blackhole would evaporate before the object would pass the horizon. So it seems like passing the event horizon is purely theoretical thing that would happen under a static, unchanging blackhole. But from a more wholistic perspective, the object would be fried by gamma rays and extremely high energy hawking radiation, it's quite possible the hawk radiation would apply outward pressure too. The only time the blackhole would truely grow is if matter outside the blackhole could cause the horizon to expand outward. Also one of the spacial dimensions becoming "time-like" seems rather crazy and I hazard a guess that would be fairly observable phenomenon as well. So I've been very intrigued by alternative models.

[@perryallan3524]

Some of the aspects of this "new" theory were the basis for a science fiction story I read at least 50 years ago. That a very large black hole could be its own "mini universe" with galaxies and stars - and you could move around within it. If I recall the science fiction story correctly some "elder" race had created their own super massive black hole "mini universe" as they were not happy with the normal universe and wanted to withdraw until something changed in the normal universe (and they had done things to enable that change). This elder race had the science fiction capability to leave their mini universe black hole and look at the normal universe from time to time to see how things were progressing.

[@ivankirkpatrick5884]

Black holes have spin, likely very high spin rates since conservation of angular momentum means anything falling into the black hole brings in some spin which gets faster as it gets closer to the center of spin. The spin results in frame dragging among other things, which distorts spacetime. Also time slows down for the object falling into the black hole. At the horizon, time stops. Like an ice skater pulling in her arms so she spins faster. Black hole spin has a lot of interesting ramifications to the physics.

[@Spherical_Cow]

Time slows down only from the point of view of an external observer outside the black hole; for the object falling in, time keeps on progressing normally. In Relativity, all inertial perspectives are equally valid, so there's no point trying to make absolute inferences.

[@kenw9722]

Thank you for the content. I think it might be beneficial to the audience if you provided sources for your information to non-paywalled sites so it is easier for the public to access this information (arxiv vs iop in this circumstance).

[@emodude35]

Clearly there is some kind of fusion reaction going on inside black holes that produce gravimetric (dark) energy, and form extremely energy-dense spatial particles that create a different region of space with its own fundamental properties. Hopefully further research on QCD can determine what this reaction might be.

[@damo408]

Been saying this for years. Black holes are stars that are in dark mode vs glow mode. It’s replicated in the lab, meaning dark mode vs glow mode plasma.

[@starventure]

Red Supergiant - "I am strong" Neutron star - "I am stronger" Black Hole - "Who do you think you are kidding? I freaking bend light!" Supermassive Black Hole - "Dude...I sit at the center of galaxies...how strong do you think I am?" Sun - "I exist..."

[@duroxkilo]

there are so many ppl saying so many things (and that's fine) but it appears it's extremely difficult to build a coherent working model of sorts at this point. at some point someone will achieve a breakthrough and maybe the solution will be elegant and 'simple' to grasp...

[@uiteoi]

Doesn't the paoli exclusion principal prevent the possibility of a singularity ? What happens as the last neutron falls onto a neutron star before it becomes a black hole ? Do the neutrons decay into something else, such as leptons ? If they remain as quarks, the paoli exclusion should prevent the singularity ?

[@DoctyrEvil]

The singularity in a black hole is a mathematical convenience with inconvenient implications. We model normal Newtonian masses as point masses, which are singularities, but nobody thinks there is a singularity in the center of the Sun or the Earth.

[@user-if1ly5sn5f]

3:39 it’s not a miracle but think of stars colliding and the difference pops up, gotta be some sort of integration or something. Miracles are like the stars aligning without understanding. We can align our neurons to reflect the differences and predict. It’s hard though when you only have 1 and are trying to find 100 or something though.

[@Desertphile]

Thank you; this video is awesome. Am I incorrect in recalling Carl Sagan's COSMOS television series mentioned stars and galaxies might be in black holes? I thought universes can be infinitely scalable.

[@neil1629]

Using nested black holes - I mean gravastars - to solve the singularity problem doesn't come off as too surprising. If the numbers go to infinity, just move up to a bigger type of number - they're basically just 3d-nested fractions. Just like the set of reals is bigger than the set of integers, even though they're both infinite.

[@anthonycarbone3826]

I have a question...What does the opposite side of the black hole look like and what is the supposed depth of a black hole. I am guessing that the stars revolving around a black hole are caught in a tight elliptical orbit around the event horizon on a singular plane of unknown depth. Now our solar system is mostly planets revolving around the sun in a somewhat tight elliptical orbit but the earth's moon orbits the earth on the almost same elliptical plane so it would be impossible for a star to orbit a black hole in a manner that goes behind the opposite side of the event horizon (perhaps called the singularity) of a black star. But the black hole is not the end as there exists other heavenly bodies directly behind the black hole in a depth perspective at some given distance within the same galaxy.

[@danielh.9010]

About what it looks like to cross the event horizon of a black hole: Here is a high-quality animation: kzbin.info/www/bejne/aqO3p2ytq9uUqpo About the depth of a black hole: the distance from the event horizon to the singularity is simply the radius of the event horizon. I think you're probably misinterpreting animations illustrating the gravitation near a black hole that depict a rubber plane that stretches downward where the black hole is. These animations are not a 3D depiction of actual space, but substitute one dimension of space with gravity instead. In summary, the event horizon simply takes the form of a sphere, and the singularity is in the center. By the way: the event horizon can have other geometries as well, it's not limited to spheres (e.g. en.wikipedia.org/wiki/Ring_singularity ).

[@timgerk3262]

In addition to the mathematical solutions (i naively assume these are steady-state solutions) shouldn't there also be a plausible process for transition from the prior matter-energy distribution? The nested shells has an appeal: the ancestor star is divided in shells by the speed of light limit, such that no gram or erg really disappears into an infinitely deep well. Im also comforted that the holographic principle fits to the asympotically dense & thin shells.

[@LauRoot892]

Hi Tim 👋

[@michaelkaliski7651]

“It’s turtles all the way down”, as Douglas Adams may have remarked. Given the essential truth of many of his other musings, gravastars may well be a decent solution to the black hole problem.

[@justtrolin]

this analogy is pretty cool, as it could illustrate that the universe is just layers of blackholes superimposed on each other like russian nesting dolls. but just how mindbogglingly massive would such a layer have to be for us to enjoy relatively coherent existance? like ripples in a pond, each ripple is its own universe with the edge of its wave its own end to the observable uiverse. which is for its sake and reference, only the parts of the ripple they are riding on that they can see. cool. cool story bro.

[@nixboox]

The problem with using binary black holes as a measuring device means they have a unique problem of having to orbit a barycenter. So they are likely not really acting as black holes until they complete their merger at which point we STOP seeing the gravitational waves which means the black holes are NOT rotating when they're individuals.

[@moodiblues2]

Ever since I learned about black holes and the big bang I wondered if the big bang was the product of a black hole in another universe in a multiverse. I felt that this would solve two problems. 1. there’s no need to theorize a singularity and 2. This would solve the issue of the loss of information in a black hole. Our big bang would be opposite of a black hole, a white hole spewing forth into a new universe matter swallowed up by a supermassive black whole in another universe in a multiverse.

[@bestaround3323]

But the mass isn't gone, and the information may not be lost