Are Black Holes Actually Fuzzballs?

[@InfinitiesLoop]

The best thing about PBS Space Time is that I feel like I’m being taken along the journey of discovery that even the cutting edge physicists are on. It’s not just a channel to learn about already accepted physics. It’s exploration. Thought-provoking. Thank you.

[@yendorelrae5476]

It's the music!

[@alphamineron]

Yea I feel the same, only that I get the illusion of understanding after each video… so I don’t really go anywhere lol

[@ossiehalvorson7702]

One of the only educational resources I've seen covering the problems scientists are on rather than the problems already satisfactorily solved. That's what keeps me subscribed and coming back.

[@eerievibes6854]

And its hosted by gay wolverine

[@withnosensetv]

100% agree. And even more so since they never dumb things down. While they do explain things in a ways that's a bit easier to grasp, they don't hide away the fact that a lot of this stuff is mind-bending

[@PseudoPseudoDionysius]

(As a humanities scholar with a brain too tiny to fully grasp the nuances of this sort of thing) there’s something actually great about the way this show never patronises its audience by simplifying the ideas to the point of distortion. It refuses to pretend really complicated scientific topics are simple without handwaving the facts away, and still produce something compelling enough to *want to* grasp. These videos always remind me how if you’ve learned something interesting but you’re still kind of confused, that’s actually a good thing, because it means you haven’t been duped into thinking you understand something which you really don’t. There’s a certain humility that intellectual challenge breeds that’s really valuable.

[@jamespage6013]

underrated comment

[@sntslilhlpr6601]

I appreciate it as well. It's hard to because most of these vids make me feel stupid. But I'd rather feel stupid than confidently incorrect. This channel is pretty unique in my eyes. It occupies a rare niche between pop-sci and textbooks, much like QED by Feynman. And that's high praise. Only other channel I can think of in the same category is Ben Eater which has real word Comp Sci stuff, which is totally different but similarly mindblowing. From black holes, to subatomic particles, to ones and zeroes putting these letters on your screen, it's all magic to me. And that's why I'm interested.

[@PrivateSi]

Humanities have gone down hill... I blame Social 'Science' infiltration.. This show is part of the neo religion of Scientism and this guy is a Scientism Preacher... It's also very behind the curve, only questioning dogma when a million other mainstream outlets have started questioning bad dogma (such as 'String Theory' becoming the neo poster child for advanced theoretical physics and TOEs).... It's full of woke jokes and leftist BS on top. Source Analysis is the cornerstone of historical research, with Bias Analysis about the most important part of source analysis. Bunch of Climate Alarmist mass-drug pushers, like ALL the other mainstream sci-news channels of the Internazi Neo World Order... ..!..

[@Harmonicaoscillator]

Graham and Mike, Thanks for your comments! I currently am studying physics in California, and I must say, reading that people from all walks of life find joy in pondering the subject brings me happiness. I often study philosophy in my free time with the exact same wonderment you guys enjoy these videos with :) I often find I have the best discussions about physics with people whose background is not in physics, ironically. Their minds are often not as constrained by the equations we learn, and more willing to ask the big, weird questions that I saw other physicists asking when I was young- the very same questions that made me decide to take the path of physics. I hope you all have an awesome day today :)

[@squintyourears]

Well said

[@Traventine]

The answer "there is no inside of a black hole" makes so much more sense to me than "there is an inside of a black hole but it's causally disconnected from our universe and space acts like time and time acts like space and there's an impossible dot at the center that breaks physics"

[@L2p2]

As per relativity if somethings falls into a black hole it will cross event horizon and feel nothing. This means there is an inside of a blackhole as per relativity. it as if the information is left out in the Event horizon as the stuff inside is casually disconnected as it to keep entropy in balance

[@medexamtoolscom]

I've been saying this since 2005. I've been expecting the firewall hypothesis since before the word was even used for it. Because the temperature of the hawking radiation should be only as cold as it is because it is extremely redshifted, but if you fall in, it becomes more blueshifted, or rather less redshifted, and that ADDS to the velocity blueshifting of falling toward it, so it should reach the planck temperature as you get close to the event horizon, which should annihilate the reference frame itself. People kept telling me that the hawking radiation would disappear if you were in freefall because it is just a form of unruh radiation, but that makes no sense, if you're even a few feet away from an atomic nucleus sized black hole where its gravity is negligible, being in freefall isn't going to make its terawatts of nasty radiation disappear to you.

[@anonymous-rb2sr]

what about the answer "there is an inside and it isn't disconnected" lol the event horizon is literally a structure that is a result of the inside of a blackhole, there, your "there is no inside" theory is disproven, next

[@icy3037]

@@anonymous-rb2sr are you being serious

[@Daniloxidado]

@@anonymous-rb2sr we might need a little more than "nah it's the opposite you're wrong" to disproven that theory

[@LucasHenderson]

I worry everyone's ignoring the most important take-away: Black holes may actually be Flying Spaghetti Monsters.

[@olbluelips]

Now im hungry :(

[@jamieg2427]

checkmate, atheists 💪

[@artiomgera6686]

They ain't flying. They laying on the edge of spacetime, just chillin

[@badendhappy2903]

Ramen!

[@koolkid121998]

😳

[@aguywithanopinion8912]

I've been waiting for a video like this for ages. How could a black hole possibly have an interior considering nothing can ever get there from our perspective? This video clarifies so many issues with black holes. I'm now officially a string theory fan.

[@bramkivenko9912]

The problem is that a traditionally imagined black hole could form with stuff already in the inside. This pushes that stuff outward using expanding space because that's the only way you can move away from the centre of gravity without faster than light travel. Overall, I these concepts must be a closer explanation to reality than the traditional description of a black hole.

[@Mark_Cook]

@@bramkivenko9912 What about hyper-massive blackholes?

[@GalactusTheDestroyer]

@@Mark_Cook The universe's largest fuzzball of course! :p Black holes are freaking awesome and scary as crap at the same time.

[@superchinmayplays]

@@GalactusTheDestroyer i have to find that cat

[@anonymous-rb2sr]

average string theory fan vs average science enjoyer

[@Jawnderlust]

The level of quality in all the PBS Space Time videos is astoundingly consistently astounding. Kudos to the entire team and the contributing community.

[@stanimirborov3765]

yeaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

[@arkoutarkout3654]

You can get more info in 18min then 1h show on discovery Canada if they even do science now

[@iJosiah]

Astoundingly consistently astounding..? lol

[@medexamtoolscom]

It's certainly higher than most. Surpassed only by dialect's. And possibly the science asylum's. But there's a big mistake in this one. At 1:41 when he says 10^(10^77) bits, no it's nowhere near that, maybe 10^77 bits but there's only 5*10^123 bits of information in the entire universe. And I don't see any note from them correcting this. So still, beware the things he says, they're still not reliable.

[@BlueZirnitra]

​​@@iJosiah astoundingly consistently astoundingly consistently astounding.

[@ms-ds3wv]

This was one of the better string theory episodes, I think that the discussion of whether string theory is right or not is kind of beside the point. The real value in theoretic models like string theory is that it offers alternative views and solutions that can be important stepping stones for inspiring future theoretic models that can be tested. We have seen this before with theories like the one electron universe. Really hoping for more episodes on thermodynamics and especially how statistical thermodynamics is useful. Also how about an episode on the challenges with designing commercial fusion reactors for power production. Like comparing the differences between how fusion happens in the core of stars and in reactors, how parameters like pressure litteraly differs atronomically in scale.

[@SToNeOwNz]

I agree, as this video shows it has some predictive value. We had counters before abacuses and then calculators, as our understanding grows so does the realised complexity.

[@stapler942]

That feeling when your quantum objects decide to take "fuzzy logic" to a most literal degree.

[@goldnutter412]

oh you said feeling you mean seeing is believing ? pass it on thanks *spams staple button* kzbin.info/www/bejne/n163aKd5grp3jrc that was hard wasn't it NEXT. Cold Atom Lab ? yeah Rob Thompson already knows all about it long ago. NEXT ? well that other URL there when i was raging has 3Blue1Brown and why he loves 808, etc etc etc NEXT ? what is "squared" what is "cubed" what is MOV ? waste of a delete key if you're us.. why not just choose then render it in own context ohh that would be efficient and own database ? and remember things ? well that might bee efficient always has been

[@Vastin]

So, one of the really fascinating things about a black hole with no interior is that it transforms from one of the simplest objects in the universe (as described by classical GR), to one of the most complex objects in the universe. If you have a sphere with no interior, with all its 'information' encoded on the event horizon, that means that not only are two points next to each other on that 'surface' adjacent to each other - but presumably EVERY point on the entire surface is effectively adjacent to every other point? Choose any two points on the surface, and they will be adjacent to each other, because there is no interior volume to keep them apart from each other. The two sides of the black hole that we perceive to be kilometres or even light hours apart are in fact directly adjacent to each other. This means that every particle (or bit, or stringy waveform or whatever), can in principle be interacting with every other one, all at once, in the most massive objects in the universe. What's the theoretical computational output of something like that? It would help explain the maximal entropy...

[@Bob-of-Zoid]

It has an interior! It's filled with multidimensional Schrödinger cats! (

[@cebas7]

@@Bob-of-Zoid all heil the Hyperdimensional Quantum Cat!

[@kellyorator9007]

you know what, you just might be onto something for immense computational output of universe being perceived by humans

[@Jake-hd7lt]

Saving

[@Smerpyderp]

Damn. So we could make modified matrioshka brains to feed off the radiation, and assuming we could make it thin enough and close enough to the horizon, it would essentially be a galactic supercomputer wrapped around a Planck length.

[@MSheepdog]

Do I remember you mentioning once that the total information held in a black hole was based on its surface area not its volume? If so that matches pretty well with the whole 'fuzzballs have no inside' thing.

[@iKentEven]

I remember that too

[@TheClintonio]

Isn't that the Holographic principle?

[@juzoli]

Which surface? Every time you add mass to the black hole (or remove by Hawking radiation), the black hole has a new, bigger (smaller) surface. Add up all the surfaces, and you are back to the 3D model…

[@danieljensen2626]

@@juzoli The entropy of a black hole is proportional to the surface area of the event horizon IIRC.

[@juzoli]

@@danieljensen2626 It is coming from the Swartzchild equation, and the fact that the black hole is NOT an object made out of the matter falling into it, but an area of space. And “proportional to it” doesn’t mean there is information encoded to the surface. Actually it is theoretically impossible to have all the information encoded into the surface. That would mean if the black hole grows to twice its radius, then the information travels OUTWARDS from the old surface to the new, bigger surface.

[@michaelniederer2831]

5-stars: "You know what actually doesn't exist? Paradoxes."

[@HWM636]

This host looks more and more like the little guy from game of thrones, each successive episode.

[@neonparisian1296]

This channel inspired me to major in physics. Thank you so much for exposing me to so many exciting and wonderful ideas. I’m in my sophomore year of college right now and I hope to go to graduate school, it’s all thanks to pbs space time and my high school physics teacher. 🙏

[@Matt198d]

Awesome! Keep at it, the world needs more physicists

[@douche8980]

Funny thing about physics is that the more you explore and learn the more you question your own knowing of reality and infact it will challenge your own knowing of this reality (which is highly flawed quite honestly).

[@mynamejef7963]

@@douche8980ignorance is bliss my friend

[@1123Jester1123]

How's that going?

[@neonparisian1296]

@@1123Jester1123 it’s going well! In my senior year now and still planning on graduate school. Doing astrophysics research this summer :)

[@LookToWindward]

I’m becoming much less of a string theory skeptic after watching these videos. There still might not be any direct observational evidence, but the theoretical “coincidences” are piling up fast.

[@michaelcorcoran8768]

Yeah, although I try to remind myself that nearly all of the major pop culture physicist are stringy. I'm really not getting a whole lot of the other argument unless I go look for it.

[@Ryukuss]

making me think we don't know as much as we think we do

[@dabmane]

Very easy to have coincidences when you have 11 or so dimensions to work with 😂

[@jarehelt]

M theory fits the math neater than string theory, but it's the same general idea

[@tompatterson1548]

It’s still just a religion

[@Tubluer]

It seems to me that anyone with a well-developed intuition for physics would immediately sense the likely correctness of the fuzzball model. How could a model the incorporates multi-dimensional cats, hairballs and black holes possibly be wrong?

[@filobio6871]

Good question

[@brianhendsbee3264]

Me was happy

[@therabidsquirrelsage3388]

Oh thank God you were kidding. When I started reading this comment I almost put my head down in shame and left the room. 🤣

[@cautemoc4624]

@@therabidsquirrelsage3388 I mean, it makes sense from a intuitive perspective. Like the video said, neutron stars condense atoms so close that they form a solid. So something denser than a neutron star would condense matter down even further, into it's subatomic particles. If those are strings you have a string ball.

[@chrismiddleton398]

Did you mean a well-developed intuition for the internet? :)

[@WildStar2002]

Woah! I made that! 7:17 😁 Imagine my surprise to see something so strangely familiar while watching one of my favorite KZbin channels! 🤔 Awesome! 🤭 Thanks and keep putting up such excellent content! 😄

[@PSG_Mobile]

Congratulations!

[@WildStar2002]

@@PSG_Mobile Thank you! 😁

[@leifswenson1092]

Yeah congrats! That's really cool! Thanks for sharing.

[@Jwtg_angryrexy]

Congratulations

[@AThagoras]

"You know what doesn't exist? Actual paradoxes." Yes.

[@timbruns1636]

At least they are non-perceivable.

[@innocentbystander3317]

@@timbruns1636 Proof that they are imperceptible? What if we can in fact perceive some paradox, but our brains cannot interpret what we perceive, so what we do think we perceive is not at all what we actually perceive due to some form of pareidolia? Have I established "reasonable doubt" yet, or is that a complexity we no longer conserve in favor of feelings?

[@MemphiStig]

how ironic

[@dlevi67]

@@innocentbystander3317 Methinks you have just solved the problem of SCP-055

[@MrFreakHeavy]

@@innocentbystander3317 Well, paradoxes exist only in our mind. So long as we can't prove that paradoxes can exist without needed something to interpret them as such, we can say that the act of interpreting them is the same as the act of percieving them, meaning paradoxes are imperceivable.

[@will20042]

So if we have a neutron star on the brink of collapse into a black hole, will the strings already be in a larger, stretched out state? Or do they remain near planck-length until the gravity is strong enough to form an event horizon?

[@volkhen0]

In other words, how deep below event horizon is the string sphere surface? If deep below matter would have to go through some intermediate state between neutron soup and string surface.

[@viliml2763]

That's an interesting point. In classical general relativity, the formation of an event horizon is instant because it's just a mathematical artifact. The star continues to collapse under the horizon, and indeed never actual becomes a singularity because of time dilation. If the event horizon were physical instead of just mathematical, all the matter would have to shoot outwards somehow. If the straw analogy is accurate, perhaps it is space itself that crunches up to the surface at the speed of light, and as the matter suddenly finds itself closer and closer together due to the space between it disappearing, the strings forming it combine and stretch out. There would be a brief unstable state before the true fuzzball forms.

[@JosePineda-cy6om]

I was under the impression there was an intermediate state between neutron star and black hole, the quark stars. Probably in quark stars the strings start to get stretched to ridiculous lengths...

[@Leptospirosi]

@@viliml2763 "shot outward" in not exactly the correct word: as the "inside" ceases to exist that is no outwards to shot at. If the space itself bends outwards the strings would simply stay where they are like in an Alcubierre deformation where the object stays still but the space itself displace it. I guess words do not give justice to what it's a mathematical concept.

[@volkhen0]

IMHO the strings don’t merge before EH is created. I think you need more gravity to merge quarks into long strings then to crate EH. EH is nothing special, just spacetime bend big enough to bend light into circle.

[@ethereal2620]

You know a video is top tier when not only it tackles complex questions but leaves you with more questions than before.

[@SuperStingray]

Really interesting video. String theory is still unfalsifiable, but this is probably the best case I've seen made for it. And I've often questioned if black holes even necessarily have to have an "inside" for the same reason it seems paradoxical to ask "what happened before the Big Bang?" They're both edges of the canvas we call space and time.

[@n0tthemessiah]

unfalsifiable =/= not yet falsifiable

[@Napoleonic_S]

I can't even comprehend what could be in or at outside of our so called space time may be like. "places" where absolutely nothing actually "exist"?

[@Napoleonic_S]

I can't even comprehend what could be in or at outside of our so called space time may be like. "places" where absolutely nothing actually "exist"?

[@AllTradesGeorge]

Unverifiable, perhaps...anything can be falsified...

[@kx7500]

reality is unfalsifiable

[@TiberiusXVI]

In a weird way, this feels kind of intuitive. If nothing can cross the event horizon, perhaps the answer of what is on the other side is exactly that. It seems the paradoxes arise from assuming anything ever reached the other side. I mean, we already know from the perspective of an outside observer, it takes infinite time for a photon (or anything else) to cross the event horizon. And we already know it takes finite time for a black hole to dissipate. So, from the perspective of an outside observer, nothing ever enters a black hole. It just gets stuck on the surface for a very, very long time. It's like we've been thinking about black holes all wrong. The gravitational force isn't so strong that it collapses, rather, it is so strong that it can't collapse without breaking relativity, as time is effectively frozen on the surface.

[@0verClockin]

Nope

[@marccowan3585]

If you fell into a black hole, and survived spaghettification, you’d cross the event horizon in finite time (even though to an outside observer it would appear like you froze on the horizon) so this can’t quite be right unfortunately

[@0ptixs]

Huh this is so interesting, what if space time exerts forces back on the mass that keeps it from collapsing, idk if that makes any sense

[@cautemoc4624]

@@marccowan3585 We don't really know this is true. For all we know, if an observer survived spaghettification, they'd just observe time passing extremely quickly as they approached the surface until eventually the whole thing just disappeared out from under them.

[@TiberiusXVI]

@@marccowan3585 Full disclosure, I am not a physicist, but I totally agree with what you're saying, if you model a black hole as existing infinitely. But we know the black hole doesn't exist forever, so that model doesn't really make much sense. The GR model seems to suggest from the outside observer perspective nothing ever crosses the event horizon, and yet the existence of Hawking radiation and evaporation of black holes suggests, sometime before infinity, everything that fell into the black hole will be emitted. So, I mean, maybe there is some weird quantum relativity reality bending going on, but as far as anyone outside the black hole is concerned, it would seem black-holestranauts never get the pleasure of crossing the event horizon as, after they are turned into spaghetti, they are converted into Hawking radiation, and sprinkled into space over the eons. Good discussion though. We are but mere mortals here.

[@134StormShadow]

Ok, having seen the furballs might cats produce I can agree with these theories. The gravitational attraction they exhibit towards carpet fibres is enormous and makes it almost impossible to remove them.

[@SlinkyTWF]

Shroedinger's Hairballs.

[@Gamesaucer]

Honestly, this sounds really cool. The idea that a black hole is essentially the edge of spacetime is, well, oddly compelling. In a universe that's for all intents and purposes infinite, the idea of seeing the edge is such a strange one, but also such a cool one. They're holes punched into the fabric of spacetime itself due to gravity in excess of what the universe is able to support... sort of like living in a block of Swiss cheese... or seeing bubbles of nothingness. Whether or not it's actually the truth, it's an interesting change of perspective on the nature of the universe, making me think about it in ways that I haven't before. I very much look forward to physicists figuring out more, and giving us laypeople yet more new perspectives. Science is such a wonderful thing to see in action, because even the wildest ideas can turn out to be meaningful descriptions of reality when rigorously tested and refined. And in the meantime we're left pondering them. As a side note, I imagine the Penrose diagrams of black holes that have been shown in videos before no longer hold if this is the case? I mean, I wasn't expecting to get spit out of a white hole in another universe upon jumping into a Kerr black hole with its "ringularity" anyway, but that was still a compelling idea in its own right as well.

[@kliersheed]

also fits well with the whole expansion thing. imagining a baloon blowing up and our whole universe is the surface of said baloon so everything expands simultaniously at all points in the universe. and the black holes would be the matter thats to heavy for the baloonsurface (spacetime) to support it so it would break through. just that whatever makes the baloon expand, doesent escape through the holes like air would, it still keeps the pressure up. so maybe if you went through a black hole you would come into the inner of that baloon and find out what that force is that expands the universe. maybe its just void. or maybe its like a plasmodesm of a plant from one cell (universe) to another. so a parallel universe thats same as ours but the opposite (like we are 1 and they are -1) and before the big bang there was only 0. sero being the equivalent of everything, as 0 can be // -4+4 //or // -2 -5 - 6 + 3+3+2+2+3 // so basically like our universe is stable by having positive and negative partilces and forces, forming atoms and stable planetary orbits etc, another universe could be the stabilization for our universe, or maybe several universes in subsumarium stabilizing each other. and the black holes would be where +1-1 are no longer stabilized (by space time) and collide, negating each other (void) while at the same time maybe new things can be created (asl ong as they are null in total). or maybe the universes arent entirely stable yet and the black holes are the places where it equalizes the differences until its really stable? like cells exchange ions.

[@chrismiddleton398]

It's also cleaner than the pure relativistic inside, where time becomes space-like and space become time-like and nothing can happen anyway until after the end of time... ugh.

[@CaptainCuttlefish74]

I'd assume the Penrose diagrams wouldn't hold up, since those are attempting to model the inside of black holes, and you can't exactly model the inside of something that doesn't have an inside.

[@traekas7228]

“In a Universe that’s for all intents & purposes infinite,…”. Just wanted to say that there’s been a recent report on this (from Anton Petrov[?]) that says that the Universe is not infinite, it’s now theorized that it’s shaped like a donut 🍩. I mean, who knows what lies beyond our reach, past our furtherest explorations, to date? All we have is the Known Universe, shaped like a Coppiceman’s breakfast.

[@andromedadelux]

Or maybe more like a barrier. A field that does not let information transcend or transform itself OUT of space time.

[@neopalm2050]

"Its interior isn't empty, its interior doesn't exist."

[@unvergebeneid]

Yeah, that was 🤯

[@Raptorel]

There's also a complementarity part that you left out that says that someone can fall into the fuzzball and from her perspective it looks like it fell through the event horizon but from an outside perspective it looks like it crashed on the surface of the fuzzball. The way this works is that the fuzzball starts vibrating in the way the person "hit it" so both perspectives are true, that vibration looking like nothing happened from the person's perspective. Pretty wild.

[@Vastin]

This largely depends on whether the 'translation' of being smashed into 2D and then 'projected' into a holographic 3D coordinate space preserves the relative coordinates of the thing that fell in. One can have a non-random, but extremely different coordinate translation that preserves your information, but does not preserve YOU - like a funhouse mirror but to a far more extreme degree. In that case you've likely stepped into reality's most efficient wood-chipper. In principle the information that described you is all there, it's just been reordered in a manner that would essentially appear random to an observer within the 'interior' 3D space. Honestly, I've never bought the 'you won't notice an event horizon' argument, because its based on GR - and GR just doesn't work at the EH. It returns an infinity, and any infinity, even a supposedly 'nonphysical' one like the EH, is a bad sign for your theory. There's also the problem that tidal forces and the apparent density of a black hole fade as it gets bigger - when we can be fairly certain that no matter its size, a black hole represents the maximal possible density in our universe (plank density?). That only works if it is 2D and the EH is essentially physical - though perhaps physical in a very different way than we are used to seeing in macroscopic objects. On the other hand, the translation could be completely isomorphic and you'd just drop through into a separate 3D coordinate space as if nothing had happened. I don't think that's likely, but who knows at this point?

[@nichl474]

her? Who is she?

[@Raptorel]

@@nichl474 the evil woman thrown into the fuzzball, of course.

[@dominikbeitat4450]

Dr. Space Time: "Hyper-Dimensional Quantum Cat" Me, an intellectual: "Ah, yes, a Flerken."

[@rae5679]

aw cute flerken kitty so adorable! yay cosmic kitty(:

[@martinelduin2214]

Another Flerken hairball on the carpet?? wtf!

[@ava_niche]

And the hairball is the Tesseract, explaining why when someone breaks through the fuzzball (i.e. touches the space stone), they get teleported to literal nothingness

[@acetate909]

A paradox is whats left over after an incomplete theory is applied.

[@TimecastGaming]

Minus the strings being the surface, this was always my sort of internal theory of black holes. The entirety of the mass existing purely on its surface while the inside being the absence of space or time. The idea of a singularity has always bothered me. And because the surface of the black hole expands as it gains Mass it stands to reason that that's where the mass is going. The confusing part was that I don't think it's surface area increases its size relatively to the mass it gains if that mass is thought of as particles. But if that mass is strings, and those strings can stretch. It just makes perfect sense.

[@Vastin]

Yeah, the weird thing about a black hole event horizon, is that its rate of growth is LINEAR to the mass dropped in, while with a sphere of (ideallized non-compressible) 3D matter, that rate is always the Cube Root of the mass. This suggests that not just one, but TWO dimensions are being compressed out of existence when you hit the event horizon, otherwise we should see expansion at the square root of mass (2D growth rate). As strings are themselves 1-dimensional objects and if they follow this odd tension structure as explained in the video, then that might address the linear (1 dimensional) growth rate of the EH.

[@DemoniteBL]

Interesting, my "internalized" theory of black holes ever since I first learned about them was that there was no singularity, but instead a sphere of matter below the event horizon. I believe there are reasons why this can't be true, but I also could never wrap my head around singularities (or ring singularities).

[@MultiTipsie]

Nice to read that my logic is mostly the same as that of others here! I had the same idea, minus the calculations which I do not have any conscious knowledge about at all, but plus the strings, be it in a slightly different form. I am really a noob here I realize, now reading everybody's comments.

[@darkonyx6995]

It's good to remember that gravitational black holes also do not have a singularity, since the singularity is not anywhere inside it, but at the future of whatever enters the black hole, due to the shifting of space and time inside. Not only that, but take fuzzballs with a grain of salt, even if they sound perfect and logical, there is no real evidence to back them up yet, a lot of discarded physics concepts were mathematical beauties that made complete sense, yet, they were discarted for a series of reasons. M-Theory might be a mathematical beauty, but unfortunately, it isn't a falsifiable one, while gravitational black holes can atleast be somewhat predicted with current physics.

[@APaleDot]

You're telling me a man named Cumrun developed a theory where what we thought were holes are actually hairy balls. You can't make this stuff up.

[@djtan3313]

Samir!

[@heisenmountainb6854]

Underrated comment lmao 🤣🤣😂😂

[@coreyschroeder9442]

@@djtan3313 Samir mathur and Oleg lunin, I personally studied under Lunin. Genius level!!!

[@michaelkaliski7651]

Answers to any problem can be obtained by applying string theory. The problem then becomes one of picking the correct answer from an infinite number of possibilities.

[@finnerutavdet]

Are you saying that you believe in multiverses that are not even atomic in their nature ? ...............

[@drdca8263]

*from an extremely large but technically finite set

[@Kirkaiya]

This was an awesome episode, and amazingly, I followed all of it. Fuzzballs are an amazing idea - that spacetime itself could have this 2D spherical surface, a shell of sorts, which has no interior, is mind-blowing. Thanks so much for making it all so clear!!

[@editingdude122]

As the years go on the camera gets closer and closer to Matt

[@ExternusArmy]

Matt looks especially like a wise tramontane monk that teaches you a new ability in this episode.

[@SimonClarkstone]

Something about the way it is shot makes his proportions seem odd. Like it was shot from much closer in than usual or something.

[@AndrewKamensky]

@@SimonClarkstone lol I'm getting some bobble head vibes

[@gentrymiller3170]

@@SimonClarkstone i think the camera was slightly above and angled down to cause this

[@maalberico]

Can everyone just grow up and stop picking on Peter Dinklage?

[@TheLifeOfRyanB]

I always wondered what that "Woah, I know Kung Fu" moment felt like. Maybe I do already.

[@jargontrueseer]

For 2022 could you guys make a "current science recap" of sorts? I feel like it would help me ND many others if you could summarize all currently proven theories about reality so that we have a base for moving forward. Theories are awesome, but some people, including myself, get quite confused about what is theory and what is fact in our current time of innovation in theoretical physics.

[@painstruck01]

think of a scientific theory as a fact that can be tested. "the sky is blue" is my scientific theory. test it to see if it is true, and you will learn more about the sky.

[@jargontrueseer]

@@painstruck01 thank you but that's not what I'm talking about. I do what science I can when I have time, but I'm not able to do every quantum experiment or get a good enough telescope to observe the movements of far of planets, stars and galaxies. What I'd like is a refresher of all the stuff spacetime has covered so that when they reference something I can already have a general idea of what it is they're talking about.

[@joeybru]

That seems hard. Remember, "no royal way to geometry"? Well, actually, there is: Each PBS video is an amazing effort on simplification and explan... well, at least trying to express in laymans terms the results of dozens or more years of progress - by 100s of people who had finished multiple years of training on maths&physics&etc BEFORE they became researchers. Youdeem to ask to further compress that into a paragraph.To a physicist it feels like, the result might be very shallow. Mentioning even the basics of the intricate interconnectedness of all those concepts seems... too much for a video. Perhaps a poster w the web of areas of physics, astronomy would serve u best? Did u google this? Did you try wiki'ing thode concepts you hear? Videos on string theory are even more challenging because it is a bunch of difficult, related theories. None of them is supported by experiments as we dont nearly have the energies to get down to that scale (perhaps he should have stressed this more).

[@jargontrueseer]

@@joeybru fair and that makes sense. I guess probably more of what I wanted was like a history of physics thing but that only had the stuff that survived to today's most accepted models of physics. This still would likely be a pretty big project though. Also yes! Not too long after i finally found a poster that briefly explains the main fundamentals of physics. I wish I had a link right now, but I'm sure if i found it it's still out there. Thank you for all the suggestions and corrections and yeah I agree it's probably far too much to ask. Still, at least it was a question out of curiosity which is never a bad thing! That's what led me to love this and research it myself so overall I'm happy for that drive!

[@crusaderACR]

@@jargontrueseer There are no facts in science. Anything can be doubted and remodeled, provided sufficient data. What we do know for certain is that none of the current theories hold up when taken to complete scrutiny. They break laws, or fail to reconcile the Quantum and GR "realms" I guess the best answer to give is that we know absolutely nothing for certain. We can only speculate. Which, unfortunately, would mean a rather empty video.

[@Adreitz7]

This seems to match well with the observation that, due to time dilation, no matter should ever be observable to pass into the event horizon from outside, which prompts the question of how a real GR black hole (with mass interior to the event horizon) could ever form. From my perspective, the thought experiments from the point of view of an individual falling into a black hole (in finite time in their frame of reference) are flawed because they ignore the fact that such an observer would see the rest of the universe accelerate due to their own time dilation. Close to the event horizon, trillions of years external to the black hole should pass in an instant, in which time the black hole would evaporate from Hawking radiation. Thus the observer would instead be crushed up against the event horizon before their subatomic particles are sprayed back out into the now heat-deathed far-future universe. Now that I think about it, this should also mean that the objects going into the black hole will come out in the same order that they went in, since, being closer to the event horizon sooner than other objects, they should get time dilation-teleported to the far future "sooner". You might even expect objects (or at least their constituent subatomic particles) to come out mirrored (radially with respect to the black hole) for the same reason. Weird.

[@Kullioking]

Did you just finde a way for time travel???

[@ILoveDashie20]

It already exists.

[@AWESOME100percent]

Holy! Does this mean that a black hole is like a incredibly slow explosion? So you know how you drop a rock into water, it creates a hole, and then that water comes crashing back together and then shoots out water from a crash? Could it be?

[@explesis6575]

I recommend you watch the video about falling into a black hole by science clic, where they explain that you wouldn’t see the entire future of the universe unfold, also, matter can never pass through the event horizon only relative to a distant observer, so a black hole could still form by the mass coming together and then forming an event horizon. Even if it were the case that the universe were sped up, the person falling in would still fall into the centre and be crushed before the bh has evaporated.

[@thomasreedy4751]

What observation? Do you mean a hypothesis? What you mean about time dilation. We can see black holes eat stars, that is evidence that they exist, it funnels in. We can see light bend around black holes and that has allowed us to view the same event multiple times - evidence of gravitational lensing. The Gravity is so large it bends light. But matter crossing the event horizon? We can’t see anything on the other side because light can’t escape. I don’t see how that is evidence of time dilation.

[@ruatsangawhite7261]

Matt this is one of the best episode ever, same as previous episode.. it's a banger,not that other episodes are bad they're all great..but recent episodes are a banger,the concept of non-existent spacetime is so interesting...i guess fuzz balls are just fuzzily interesting in this massively complicated yet exciting, existing and non-existing fabric of SPACE-TIME

[@Math4e]

I watched the episodes all the way from the beginning. I'm so excited to reach the discussions in the comments sections very soon. The reason I'm writing this comment thought is something altogether different! It's to say this episodes was one my favorite episodes all the way from beginning. Just omg!

[@andersjjensen]

We finally have an religious alternative to The Flying Spaghetti Monster: The Hyper-Dimensional Quantum Kitten That Coughs up Fuzzballs!

[@Vistico93]

Praise be to The Big Electron! (whoa... whoa...) Here's to hoping it will not lead to wars with each side convinced they have the One True Equation ;-)

[@RM-cv5sc]

Holy hairballs

[@jaybingham3711]

Blasphemy. Without FSM, there would be no angelhair momentum. FSM moves in slippery ways. But His special sauce undeniably nourishes all. All hail His noodly goodness. Ramen.

[@NewMessage]

" They simultaneously must exist, but can't." Like my checking account balance.

[@therret2901]

The No-Money Conjecture.

[@simpathey]

I love that what we think we know is constantly changing as we uncover more evidence about the universe and how it might work. This channel is such a fun trip, even though my mechanical physics classes I took in college didn't cover space time I am always excited to see what is on the Horizon ...and yes this was a PUN!

[@toonvank6165]

Every time I try imagine 4 spatial dimensions my brain just makes that loud “GONK” sound of a windows error message.

[@kazedcat]

You cannot imagine 4d. The way people deal with it is either just following the math or think of them in terms of their shadows and parts.

[@slipperycorruptor]

My man just described this state perfectly.. Have an upvote

[@Summon256]

@@kazedcat If you cannot imagine it - then all of those things are pointless! Because why bother describing it using math and shadow crap if in the end of the day you cannot visualise it anyway?! Sounds like a waste of time to me…

[@ritemolawbks8012]

@@Summon256 They use more than 3D geometries and other abstract coordinate systems in all physical and social sciences. In spacetime, since you obviously can't visualize 4D, you can simply it with 1-2 coordinate(s) for space, and one for time.

[@kazedcat]

Summon256 I have a surprise for you. You also cannot imagine 3D objects. What we do is imagine 3D objects in 2d perspective. We are just so good at it that we don't realize it but there are cases where this limitation is apparent. Gun mechanism are like a 3D puzzle and trying to think about all the pieces moving together is impossible. You can only imagine what you can see and imagining a moving part behind another moving part is very hard unless you break things down and imagine separate individual parts.

[@captainoates7236]

To be honest I have been struggling to understand the content of the majority of videos on this channel, gripping nonetheless. This one just lost me. I have long said that if you think you know a subject, try teaching it to someone else. All respect to you Matt for doing that.

[@ritemolawbks8012]

You shouldn't feel self-conscious at all. This video is high level and covers a specific field of theoretical research. Even if you watched every episode and had a degree in physics, it would still be abstract and difficult to understand. It would help to know Hawking Radiation, Event Horizon(s), Black hole Information Paradox, and introductory string theory, but if anyone claimed to know everything about theoretical physics, report them for trolling.

[@josheelpranlal7219]

Fantastic video. Since first delving into the quantum realm in high school (I didn't catch a zombie disease), string theory, D-Branes and all were touted as an arbitrary and lofty concept. Everywhere you'd see debates whether string theory is real or not. I love how elegantly the idea of fuzzballs handles multiple paradoxes, and how you showed us a frightening inside view of our galactic furry overlords (11:20) And can I say Matt and team bravo, this was easily one of the best spacetime edu videos I've seen in years.

[@vietthanhpham8074]

nice what if reference there :DDD

[@superchinmayplays]

wheres the giant cat

[@GideonFrazier]

Is nobody going to mention the fact that Matt literally has a bobble head in this video? Lol

[@Ignirium]

Yeah that was a little distracting noticing his head is larger proportionally to his body and trying to stop myself noticing it and paying full attention to what he's saying lol.

[@williamstamp5288]

Whyyy though?

[@Ignirium]

@@williamstamp5288 It's funny :)

[@kendallhudak]

Big head mode: Enabled

[@jonathanr.]

@@williamstamp5288 So you concentrate on his head talking instead his hands moving constantly?

[@LordAmerican]

Are we just going to ignore the fact that at 11:20 they just nonchalantly showed us exactly what's inside a black hole? It's just so ... magnificent. It is certainly the most profound truth of reality.

[@FredPlanatia]

Ok, i watched the whole thing now. Can i give you and the spacetime team an award? This was just awesome. I learned so many new things and they were so clearly explained that as a lay-interested person I feel like I really got some insight to understand better why black holes are the frontier of quantum gravity and why some feel string theory is such a promising direction to pursue. Wishing you an excellent break and looking forward to future episodes of ... Space Time.

[@drew-et1mm]

ive always had a strong belief the singularity (as a point) doesnt exist. this solution of fuzzballs and black holes as a surface really tickles my brain in just the right spot

[@Vastin]

Most of physics holds the belief that singularities can't exist - which is why its a little strange that so many articles are written about the 'interior' of black holes in GR, because we have known almost from the beginning that those GR solutions are almost certainly wrong the moment you approach the EH closely.

[@multiverseandparallelunive6224]

THE FUZZBALL ??????? SOLAR MASSES 🌞

[@Alverant]

I never bought the idea that black holes have infinite density. We say "there's nothing stopping it from collapsing further" when the strong nuclear force is overcome, but what we mean is "nothing we know for sure". I believe there is a maximum density. The event horizon isn't a thing, just a border where the escape velocity is c. Past the event horizon the escape velocity could be 1.5c or higher (if physics didn't already break down).

[@crystaldazz]

I barely understand 10% of what's being discussed, but once in a while, I learn a little bit of something. I'll never be able to learn it all, but I guess that just means there's always something more to aim towards, eh?

[@9erik1]

So if black holes are fuzzballs as a means of solving the information paradox, what happens with Hawking radiation? Is the preserved information radiated outward, "unpinching the straw" in the 1D model? Or is the fuzzball black hole effectively become a permanent boundary between spacetime and absolute nothingness? How would it even make sense to talk about such a boundary?

[@viliml2763]

I assumed that the strings separate from the fuzzball and fly out.

[@FutureChaosTV]

Imagining the strings are not motionless they should impart momentum on the surrounding fabric of space-time and maybe as such create radiation that removes energy from the "fuzzball"?

[@Sean-xc9im]

They cover that at the 8:00 mark

[@9erik1]

I guess what I'm wondering about is the deleted spacetime: is the formation of the black hole/fuzzball the precise point at which you start deleting spacetime? How does the deleted region evolve over time as the fuzzball radiates? How do the 1D strings pile up to make the higher-dimensional boundary of the deleted region? Is the conclusion of fuzzball evaporation that spacetime effectively stitches itself back together?

[@cademosley4886]

​@@9erik1 The current fashion is that spacetime emerges from the entanglement of regions of space (their quantum vacuum states). In that framework (about which I'm not qualified to say anything, but I'll handwave at something anyway), only the "touching" surface of the fuzzball would be entangling with surrounding space. There's a principle called the monogamy of entanglement that's apparently the actual mechanism that disallows the interior ("non-touching" parts) of the fuzzball to be entangling with the surrounding space, IIRC. As the fuzzball radiates away, the formerly embedded radiation would reentangle with surrounding space. Anyway, long story short, that'd be the mechanism you'd want to be looking at to answer your question. You'd look at the specific process of entanglement of every qbit in the fuzzball & outside space, when it's broken and when it's reestablished, and there's your "deleting" and "stitching itself back together" mechanisms. We know a lot about entanglement forming & breaking, so I think that part is better understood than other parts. (C.E., I have no idea what I'm talking about, lol. But all of those online lectures on blackhole "wormhole" evaporation by Engelhardt, Susskind, et al., seem like they could combined with these fuzzball ideas in these kinds of directions.)

[@kikop.2957]

As a physics student i have a question: how accurate those fuzzballs could reproduce the merge of two blackholes in respect of the final state of the new black hole (surface area, hence entropy; mass, angular momentum, charge...)? Great video!!!

[@unvergebeneid]

I would expect the theory to be a long way from being able to explain such a complex process. Seems like the one black hole that was modelled wasn't even spinning for example.

[@unvergebeneid]

@@hyperduality2838 seek help.

[@peterkelley6344]

If fuzzball A collides with fuzzball B ... one ought to have a larger Fuzzball - not a new structure called a Black Hole ... . Just thinking mind you.

[@unvergebeneid]

@Michael Bishop wait, we'd be able to measure the difference of what was it, a Planck length?

[@goldnutter412]

It's just data. There is no spoon. No screen, no computer. Just all of US and no such thing as THEY THEM ITS ALL US. ALL IN THIS TOGETHER 1/7 do a DIV in code please. 57 ? nah couldnt be 12=3 but it has to be 6 where do we stash the 1 ? 0h eye know

[@MrDominos106]

It's crazy how I can be a high school dropout and absolutely hates school but love channels like this lol

[@juzoli]

I never understood why do we treat black holes as a perfect sphere regarding gravitation. If something is falling into the black hole, due to time dilation, we “see” this thing frozen in time on the surface. Doesn’t it create a “bump” in the gravity of black hole? So the gravity right above where this mass have fallen into the black hole should be stronger than on the other side, because the mass distribution on the surface is not equal.

[@thstroyur]

"I never understood why do we treat black holes as a perfect sphere regarding gravitation" Because Penrose's theorem

[@knyghtryder3599]

İ don't understand why we consider them holes , instead of super massive objects , who's matter is strongly compacted

[@StirlingScientist]

The short answer is that Einstein's field equations are already hard to solve for highly symmetric conditions, let alone any kind of realistic case. Theorists are aware that other shapes can, and likely do, exist, but there are only so many supercomputer computation hours to go around. tl;dr: spherical cows strike again 🐄

[@ritemolawbks8012]

Yes

[@patrickcummins79]

@@StirlingScientist "consider a spherical cow" a book I read in college for my degree I never used.

[@oguretsagressive]

Since our universe also meets the conditions for a black hole (i.e. _is_ a black hole), could the expansion be explained by spinning? Of course, the expansion does not have a _spatial_ center, but in a black hole spatial and temporal dimensions are swapped, and ours has a temporal center (a moment of big bang), therefore it could be spinning around the time axis. Which also explains accelerated expansion with increasing distance from the center. I already broke my head trying to imagine this, so what do you think? Any contradictions?

[@arcura9542]

Bayblade

[@aaronsmith6632]

I've had a very similar theory for some time! Keep sharing it, maybe we can popularize this notion.

[@aaronsmith6632]

This could also explain the high ratio of matter to antimatter in the early universe, when the spinning would have been the fastest; as well as the slight preference for weak interactions in the present to generate matter over antimatter in the present, now that the spinning is slower; due to the spinning ice skater slowly opening her arms.

[@SF-tb4kb]

I had a similar thought, but there should be evidence of angular momentum, and there is not apparently. But that doesn't mean I don't agree that the universe could be a white hole. Also, angular momentum doesn't determine a particle's spin, and does not determine its charge. Spin in particle physics is not like an ice skater.

[@aaronsmith6632]

@@SF-tb4kb The angular momentum in this context is a metaphor. Since the axis is time, it would produce outward acceleration in each of the other spatial dimensions, which we see with Hubble expansion and this would explain acceleration normally associated with dark energy. Particle spin acts very much like angular momentum, although quantum in nature, and in addition to left vs right handed asymmetry with weak interactions, there are other asymmetries in particle physics, for instance there are only left-handed neutrinos, if I remember right. Arvin Arsh has an amazing video on the standard model that covers the different types of particle spin asymmetry that summarizes everything nicely. The basic idea is particle left or right-handed spin is relative to the direction the particle is moving forward in. Spin along a time axis is obviously an abstract concept, but intuitively, as association or preference for a particle to be left or right-handed would make sense. There is a known CPT symmetry in particle physics, in which simulantously negating a particle's charge, polarity (left or right-handed spin relative to its forward direction), and time produces a symmetry. So polarity and time are two of the variables of this symmetry. I hadn't connected the black hole idea to this time axis rotation theory, but all-in-all it seems very intuitive to me. I'm a layperson with an interest in physics. I've never heard this theory grace the lips of the mainstream physics community. I wonder what they would say.

[@esqueer]

If the event horizon of the fuzz ball is actually "rough," even at the insanely tiny planck scale, wouldn't the surface area of the black hole be substantially different than if it were perfectly smooth? If the surface area is greater, wouldn't that correlate with expected values of hawking radiation? If the surface area is different, is this something string theorists are looking into?

[@andrycraft69]

When you simplified the explanation by analyzing a 1-dimensional fuzzball and how you can clearly see the separation between the two "ends", my mind immediately went to discontinuous functions in mathematics. My question then is, can we talk about the interior of a fuzzball as being a "spacetime discontinuity"? And if so, is such a concept seen anywhere else in physics?

[@jomanout5866]

Move something with mass to c, same thing

[@StefSubZero270]

I think a spacetime discontinuity is more like a Singularity. Here in this case, its not even a discontinuity, its like if the whole graph on which you are describing your function would be non existent, rather than just be a discontinuity of the function

[@MarekKowalczyk]

Probably the most interesting episode so far AFAIC.

[@nickhart8212]

Firstly, thanks for such a great series, Matt and co! As a total non-astrophysicist, I’d really appreciate a layperson’s explanation to a question I've had for several years. Why can't black hole singularities be ring-shaped... My starting point: Is it true that one would be weightless in a theoretical void located at the very centre of a planet? If so, the cross-sectional gravity profile *within the planet’s diameter* would be w-shaped. The central apex has zero gravity. The w-gravity well is a 2D ring around the nadirs of the w (rotated about the central apex). Black holes: If my starting point above is not wrong, what about larger masses... Eventually large stars or super massive bodies either collapse into black holes, or large stars fail to collapse completely and form neutron stars. Instead of a collapse to a singularity, might a supernova be the extreme gravitational ripping (or rebound following collapse) of the star into this extremely vertically-stretched super-small w-shaped gravity profile (rather than a singularity point)? The ultra-dense matter/energy ring at the w-nadirs might be proportionate to the Scharzschild radius. Hawking radiation escapes in proportion to the narrow cross-sectional area of the zero-gravity apex. A neutron star has insufficient mass to overcome spherical cohesion and rent itself (or rebound following insufficiently energetic collapse) into a ring-shaped well. The above might apply no matter if the black hole is rotating or non-rotating. The singularity problem is replaced with an extremely dense, non-point ring.

[@danielobrien9502]

Yes. I tried explaining this idea to a teacher at one point: "if the mass of a black hole corresponds to its surface area rather than to its volume, doesn't it make sense that there is no inside to a black hole, that they are locations where space and time just.. arent?"

[@megalodon1726]

The mass of a black hole is proportional to its radius, not its surface area (according to the equation for the Schwarzschild radius).

[@theodorixjohnson4336]

Which begs the question….. what is the 0th dimension(space and time that just……. Dont?)

[@superchinmayplays]

@@theodorixjohnson4336 0th dimension is just a point ig

[@superchinmayplays]

In classical Euclidean geometry, a point is a primitive notion that models an exact location in the space, and has no length, width, or thickness. In modern mathematics, a point refers more generally to an element of some set called a space. (copied and pasted this lol)

[@superchinmayplays]

im probably not right im just a 13 year old watching these vids lol

[@BenLiuChungHin]

Kind of makes sense - where they have tried to explain how information can be stored on the surface of a Black hole without it falling in to conserve the Information. This will allow much more capability to store data without it going in.

[@billa38000]

I had no idea that string theory could propose such an elegant solution to the black hole problems. In your episode it seems like there is no problem with this theory. It could be interresting to explore also problems so we can have a less biased opinion.

[@matthewgartell6380]

Manscaped sponsorship would be great for this upload

[@firefly618]

This is amazing! That's a brilliant solution to the black hole "problem"

[@saltycreole2673]

Thanks for not patronizing us. Complicated ideas explained straight up. I have to watch a few times as I have no professor to ask questions about this subject.

[@erdemmemisyazici3950]

Interesting. The problem with the String Theory is that while it explains pretty much everything amazingly well, it's not very easy to prove experimentally. At the moment we need beyond-the-capacity-of-all-of-humanity type machines to test for a "string". But certainly fascinating.

[@joshhufford8815]

I've seen a lot of discussion on how you can never observe anything cross an event horizon from an outside perspective. A while ago, I had the thought that as you're falling toward the event horizon yourself, time dilation and Hawking radiation would cause the black hole to shrink before you reached the horizon, so maybe black holes actually have no interior, not even spacetime. I didn't know a lot of physics, so I did the math that I could and mentioned the idea a couple places online but was told that I didn't know what I was talking about. This (along with this channel) inspired me to start seriously learning the math behind the physics. Whether or not black holes actually work like this, it's exciting to see a theory with real math behind it predicting something that I was told was "bad science".

[@uninspired3583]

The passage of time doesn't change from my perspective as I fall in, it only changes relative to the outside observer. If there is no "interior" to the black hole, what is causing the gravitational effect in the first place?

[@joshhufford8815]

@@uninspired3583 A clock on a massive planet appears slower if you are a distant observer vs if you are on the surface. Therefore the clock on the surface speeds up as you approach it. The idea is that the rate of Hawking radiation should also speed up as you approach the black hole and if you combine this with the formulas for black hole evaporation rates, you'll get that you never reach the horizon As for the second question, I'll refer you to a cool idea called "fuzzballs" which is a construction that reproduces the gravitational effects of black holes, but does not have an interior lol

[@uninspired3583]

@@joshhufford8815 yeah I still need to finish watching the video.. Interesting. I haven't done the math, tbh. From the perspective of the one falling, how long would it take to fall to the centre of the black hole? Then accounting for time dilation between the centre and event horizon.. You're suggesting at some point the black hole shrinks and event horizon passes you by before you reach the centre?

[@joshhufford8815]

@@uninspired3583 I'm suggesting that as you approach the event horizon from outside the black hole, it shrinks fast enough that you never cross it

[@LouisChiaki]

I have been waiting for a channel that explains these latest theoretical physics research for me as a physics PhD. Now I found it! Thanks PBS!

[@svnyea7132]

@Louischiaki please you're the one who doesn't look like a bot. Isnt his head bigger than normal????

[@exhalerwolf1272]

Another episode of mind = blown¹⁰ First time I saw String Theory actually being useful.

[@crimsontwilight4501]

Hey, not sure if you’ve brought it up before, but the “quantum pressure” is at least a fourth property.

[@Njadmessi]

@johnnytheprick you are another who doesn’t understand

[@Mohammad__M__]

Well, black hole quantum pressure wasn't discovered when the fuzzball papers were written, so maybe in near future they'll add that up too. but I still wonder, is quantum pressure an independent property of a black hole? isn't it actually calculated using mass and maybe spin?

[@Njadmessi]

@johnnytheprick 1st quantum mechanics shouldn’t be taught to a five year old, but you act like that and that’s your understanding but basically anything quantum means on the very small scale. Like pressure of quarks being compressed or in a neutron star where the proton and electron combine into a neutron because there isn’t enough room

[@СавелийЖуков-ф1щ]

@@Njadmessi When that sorry excuse for a sapient being compared itself to a five-year old he insulted all five-year olds.

[@crimsontwilight4501]

@@Mohammad__M__ I mean, it’s a property, but you’re right that it wasn’t found until recently.

[@CHEVYCAMARO4GEN]

Sometimes the best science video is the one that gives you more questions than answers.

[@XraynPR]

Physics: "Alright, we got to get our naming schemes together. So many people are confused by the term Black Hole, as it's not really a hole it's a somewhat misleading name" Also physics: Fuzzballs

[@waterH-O-H]

secret leaked notes: call them _space voids_ .

[@liwoszarchaeologist]

Compelling, but aren't current VIRGO and LIGO observations inconsistent with current understandings of fuzzballs? (I have the feeling that Matt et al. are setting us up for a sequel on that very topic).

[@ComradePhoenix]

How so? I'd think the 'ringdown' observed in BH collisions would actually make more sense with fuzzballs.

[@liwoszarchaeologist]

@@ComradePhoenix intriguing, why do you say that?

[@ethannguyen2754]

I really appreciate you respecting the difference between a ball and a sphere.

[@lepermessiah2608]

Very interesting. But what would that look like to a person falling "into" the event horizon? Would they find a solid surface and then die on impact? (assuming the radius is large enough that the tidal forces wouldn't kill you first)

[@BurningDownUrHouse]

You'd smear into strings at the event horizon, just like what happens to anything else that falls in. Depending on the size of the black hole it would happen faster or slower. With big super-massive black holes it would happen slower because the warp of space-time is a more gentle slope compared to a smaller black hole which the hole drops off much sharper. Either way the end result would be the same and the time it takes for this to happen would likely not be a noticeable difference between the two, not that you would ever get to experience both.

[@superchinmayplays]

u hit string = u become string (i think)

[@mastershooter64]

I think the same thing would happen as predicted by GR, the gradient of the gravitational field (or in this case gravitons) would be so great that the difference between the gravity your head is feeling and your feet are feeling would be so large and would keep increasing, which would lead to spaghettification and a thin stream of plasma which was before you would hit the event horizon and get decomposed into it's constituent strings

[@zakzwijn8410]

I think one wouldn't see or experience a solid surface as we know it. We think or surfaces in 3d space, but since it's a hole in space itself, tbh I have no idea how would one experience it. Imagine an entity living in 2D flatland on a sheet, then punch a hole in that sheet. That entity would come across that hole, but it wouldn't experience a surface, since the hole is in a higher dimension. Would it 'warp' to the other side? Would it look like a 2D black hole with all the light bending that comes with it? Would it travel across the boundaries of the higher dimension and experience nothing particular? I have no idea. With supermassive black holes you'd still be crushed to string-size in no-time, since the pull of gravity at the fuzzball string shell is as close to the speed of light as it can get.

[@orthoplex64]

"what does string theory predict is at the center of a black hole?" string theory: "false"

[@WilliamFord972]

And this is another reason why string theory is bullshit

[@SolomonUcko]

无 (wú), null, undefined, etc.

[@jedomann]

Agreed.

[@olbluelips]

@@WilliamFord972 i don't necessarily think string theory is right, but "there is no centre" is a better answer than "something impossible occurs at the centre"

[@Numba003]

I really need to go back and listen to those string theory videos again lol. Thank you for another cool and strangely compelling episode! Stay well out there everybody, and God bless you friends! :)

[@asherplatts6253]

The whole "fuzzball has no interior" makes sense to me, it's like a 4-D hypersphere, flipping the inside to the outside... the interior *is* the surface. So, I'm going to make a huge logical leap, because, step one: the string soup of a fuzzball sounds a lot like the conditions of the early universe... Second step before the leap: gravity and time are two sides of the same coin, the more gravity, the slower the time, yeah? So... are black holes punctures in cosmogical topology that go back in time to the early state of the universe? Or put another way, is spacetime actually cosmologically flat, or does the distortion of gravity cause it to curve back on itself along the time axis, something like a 4-d Klein bottle?

[@cherrydragon3120]

The interior is solid mass if you ask me. A black hole, 4D or not can't be hollow. Otherwise it would have no center of gravity like it has

[@killerhappyface]

Not sure. There are a lot of implications and possibilities here, mostly because deleting space seems wrong to my uninformed mind. Could the space be shunted somewhere or some-when outside the black hole? Could gravity waves from black holes consuming matter be transferring the lost space to the universe by expanding it like waves on a rising tide? But even if the space is moved elsewhere or if the space is just compressed to some minimum constant for matter, that still presents a mathematical incongruity.

[@alwysnxtgen8405]

I think that the theory that math and time is universal languages. And you even pointed out that ti.e is related to gravity just as Einstein did. But humans based their early model of time and what we have now through mathematics. So we sent gibberish into space on the voyager.

[@richardsrichards2984]

Why is it so difficult to accept there is no interior??.1st evidence we have the theory of general relativity which teaches us that Nothing has ever crossed into the event horizon because of infinate time dilation...2nd bekeinstein told us the entropy of a blackhole is proportional to its surface area and not volume.....A blackhole maybe another universe i.e different contants of nature inside but by no means can we just call it a big ballon.

[@Young-ep8ik]

@@cherrydragon3120 It's not 'hollow'. Having a hollow interior would suggest there's empty space but the video is saying spacetime ends at the surface.

[@bulentkulkuloglu]

Then all your great videos on black holes with Penrose diagrams, potential white holes, neighboring universes, etc are all going down the drain. So sad, they made me love black holes. But this new approach is breath taking. As gravity was breaking the atomic structure in neutron stars piling up debree of matter in a condense form, this time black holes are breaking the elementary particles to their constituent strings. Now I like that too.

[@ArchangelApollo]

Having spent a few days digesting the information in this video, it makes sense. I even think black holes being fuzzballs solves the information paradox. Basically, in the paradox, if a friend watches you race towards a supermassive black hole, they'd see you get incinerated at the event horizon. But to you, you'd sail right through, unharmed, to the center of the singularity. If black holes were fuzzballs, you'd get incinerated and your information smeared into the fuzzball of stretched strings.

[@das_it_mane]

6:40 feel like physicists would be able to solve a lot of physics if they just did psychedelics

[@jajssblue]

Fuzzballs would be more evidence that any true creator might be a Cat. Egyptians might be onto something. Plus it'd explain why their might be some sense of a distant and ambivalent higher power. Lol

[@Alex-ck4in]

You have cat to be kitten me

[@cpresto2]

Oh man we're screwed. Game over man.

[@KadeSound]

God is the Lion of Judah so there ya go xD

[@kayden5238]

also fuzz balls being a cats faverite play thing is in the center of attention in most galaxies :O

[@zharul8716]

Observable universe is actually a super giant cat. Confirmed.

[@GiancarloPaniccia]

That might be the coolest single thing that string theory has ever coughed up.

[@tycro]

I see what you did there.

[@Aedus]

If space-time is simply absent within a fuzzy black hole, then are there surface tension mathematics that are analogous to the state of an event horizon?

[@aarondavis8943]

He didn't really focus much on the event horizon. I'm not sure whether this perspective affects it, has no effect or precludes it completely. Would love to see a follow up that connects fuzzballs more to the structural aspects of a black hole that we know and love. Like a black hole's influence on time, for example.

[@joshuascholar3220]

@hm rq it sounds like "4 dimensional time-cube" level word salad.

[@skilz8098]

​@@hyperduality2838 You forgot to mention the most fundamental property of perpendicularity. The relationship between the Sine and Cosine functions. In essences they are the same exact wave function except that they are 90 degrees or PI/2 linear translations of each other. They are exactly the same at 45 degrees or PI/4 radians. sin(0) = 0, cos(0) = 1, sin(90) = 1, cos(90) = 0, sin(45) = sqrt(2)/2, cos(45) = sqrt(2)/2. There is also an identity equation sin/cos = tan. tan(0) = 0 since sin(0)/cos(0) = 0/1 = 0 tan(45) = 1 since sin(45)/cos(45) = 0.7... / 0.7... = 1 tan(90) = ? since sin(90)/cos(90) = 1/0 = ? Thus sine and cosine are perpendicular to each other. I tend to think that the paradox of black holes is relatively related to the property of the trig functions and our understanding of division by 0. We are taught that division by 0 as well as tan(90) or tan(PI/2) is "undefined". I beg to differ. I believe it is well defined, just that the result is ambiguous... Human's like a 1:1 correspondence when it comes to calculations. They don't like ambiguity because they can not understand it. They assume that everything has to fit the foundations of a function. One input yields one output. When an expression or an equation has a single input with multiple outputs it fails the vertical line test and is not considered a function. Take for example: f(x) = x, f(x) = x^2, f(x) = x^3 are all functions. Now, let's take the equation of a circle (x-h)^2 + (y-k)^2 = r^2 where (h,k) is the center of the circle, (x,y) is a point that lies on its circumference and r is the length of its radius... Doesn't this equation look familiar? Let's see what happens when we take this equation and simplify it by examining the Unit Circle located at the origin. (x-0)^2 + (y-0)^2 = 1^2 == x^2 + y^2 = 1. Since 1 is a perfect square does this equation or formula look familiar? How about A^2 + B^2 = C^2. Hmm, isn't that the pythagorean theorem? How about 1^2 + 1^2 = c^2 hmm sqrt(2)^2... which still equals 1+1 = 2. This is just simple addition which is nothing more than a linear translation or transformation. More than that, we can take the slope-intercept form of a line y = mx+b and assume that b = 0 giving us y = mx. We know that m is the slope of the line defined by rise over run which can be calculated as the ratio of the differences in both the x and y directions from any two points on that line by (y2-y1)/(x2-x1) which can be simplified to dy/dx. When we let the slope dy/dx be 1, we know that the line bisects they XY plane through the origin creating a 45 degree angle above the x-axis. We also know that tan(45) = 1. From this we can see that dy = sin(t) and dx = cos(t). When we observe the properties of the trig functions specifically the sine and cosine wave functions... we know that they are both continuous, we know that their domain is the set of all reals, and we know that their range is [-1,1]. We know that their limits exist for every point. We know that they are oscillatory, periodic, etc... we also know that they are derivatives and integrals of each other. So what makes them different? It's their Orthogonality! The sine is an odd function and the cosine is an even function... Yet we can see that there is a direct relation between linear functions and the trig functions. y = mx+b can be rewritten as y = tan(t)x + b, or y = (sin(t)/cos(t))x + b. The simple equation or expression of 1+1= 2 is the Unit Circle located at the point (1,0). So what about tan(45)? Hmm division by 0 and all of mathematics has an issue from their assumption that division by 0 is undefined. They base their assumptions on the axioms of mathematics and won't deter. I know and understand the axioms from a logical perspective. But from a general perspective I think their assumptions are wrong. I don't think division by or 0 or tan(45) is undefined. No! I will claim that it is ambiguous! There is a subtle difference between being undefined and ambiguity. Being undefined means it does not have a definition. Having ambiguity means there is a set of solutions and we just don't know which one is appropriate. The lack of understanding orthogonality is one thing, but also the lack of understanding opposing parallelism is another. Two lines are parallel if they never intersect. How about two vectors on the same line pointing in opposite directions? for example the unit vector and its opposite They have the same length or magnitude but one is facing East and the other West with a central point between them. Their sign is opposing yet they are on the same line which has a 180 degree or PI radian angle measure. Hmm where have we seen this value before? Ahh yeah, the summation of the three interior angles of a 2D Euclidean Geometric Triangle. Why do I mention this? Because in Physics and even other fields of the sciences, we use these wave functions sine and cosine to map or graph a visual representation of wave motion (energy, sound, light, rhythms, etc...). And these trig functions are based on the properties of triangles and circles. The laws of nature adheres to the laws of these geometrical shapes. Yet these mathematical functions are based on numbers and numbers themselves don't exist in nature directly as they are conceptual or a product of the mind, yet the physical universe is bounded or governed by them. This would have to make one think or even slight be curious to then ask... If the nature relies on the laws of physics and chemistry and they rely on the laws of mathematics which rely on the properties of numbers which are conceptual or a product of the mind, then who's mind does it all come from? My perspective... I see nothing but Intelligent Design!

[@ISK_VAGR]

The problem with this hypothesis is that it introduces another incoherence such as nothingness inside a black hole. Another question is that piercing the black hole (eggshell) will result in a massive explosion or total destruction of the universe because inside the minimal energy level of the “nothing” will be 0.

[@android175]

For nothing to exist, something has to also exist. I think you are misunderstanding what the theory means. There isn’t just nothing and zero energy. Space and time do not EXIST there. You need space for that “nothing” to exist. You can’t have zero energy level if space and time there don’t exist.

[@SirLied]

I think you misunderstood what "nothing" implies insofar as potential possible phenomena. The concept of "piercing" an object implies a revealing of some material interior, usually empty space. But there isn't even any empty space in this instance, but rather a complete lack of any space at all. Think of it like this. If you are in a 1 dimensional universe where there is nothing but an eternal line, you would not humor the possibility of breaking off the line if the premise is that there is no existence of anything beyond the line. Such a circumstance is what we see here. Hope that made some sense, I don't know what I'm talking about tbh

[@bastiaanwilliams8398]

Very interesting theories. Now I can't sleep. I feel like a puppet on a string.

[@aceintheblackhole]

apparently, if you are a physicist, you fix broken things with string. if you are an engineer, you fix them with tape.

[@medexamtoolscom]

Or you fix them with a turbo encabulator.

[@nathangreene3869]

Gotta say I'm glad paradoxes don't exist... Felt like I been entangled in a few of them lol

[@bluezebra2759]

Thank you PBS for real captions, and not that auto-generated ones!

[@FeruRed]

Makes sense then that the black holes are black. Just try to shine a light of any spectrum on a string with massive gravity and (don't) see what happens. So, technically, these fuzzballs are massive "particles" that exist in all quantum fields at once, if not extradimensional.

[@LeoCoot]

I think the focal length is too small and makes your head look huge and your shoulders a bit small ( 2:41 ) (maybe it's due to the massive brain of course :D), you should try a wide-angle lens move the camera further and zoom in a bit, love your channel take care :)

[@bigjay875]

If it was any other Chanel putting up a thumbnail like that i would have skipped it as click bait. Nice work 👍

[@rkristel82]

All hail our cat overlords who created these fuzzballs for their enjoyment

[@joshuakahky6891]

*We've had this idea of being "spaghettified" as one crosses over the boundary of a black hole and nears its singularity, but what would an observer see in the case of nearing (and coming in contact with) a fuzzball?*

[@excentrisitet7922]

Here it seems that an observer should be obliterated... Just as he would in the collision with the impenetrable wall moving close to the speed of light... 😫 No extra universes on the other side. 😥 Or at least how this is sounds to me.

[@GTRWelsh]

someone else said something like... time would get faster and faster as you approach until eventually the whole thing just disappears, assuming you somehow survive the length of the black hole life span (I think, would you age faster??). You never enter the black hole because time would just speed up to insane speeds until the black hole is dead, then time goes back to normal. You'd never reach it. Interesting take, I like it.

[@unvergebeneid]

Don't worry, for small black holes you get spaghettified way before you reach the event horizon. So you can still have that fun experience!

[@McGeistly]

@@GTRWelsh I think if you were to survive, you would witness a weird morphing of the outside universe as light would be able to reach you in weird ways, and you would probably age normally, but the universe would pan out more rapidly. So you would be stuck until you starved or dehydrated and died, but would get to witness thousands or millions of years worth of weird stuff during your remainder.

[@Vistico93]

Some Lovecraftian horror, no doubt (like whatever Erich Zann saw out his window) ;-)

[@proddreamatnight]

Can we talk about how literally perfect the visual effects are for representing what's beiing said? Makes it so so much eaiser to follow along

[@LithicMetals]

Absolutely inspiring! What a fun way to visualize a black hole. I love pondering this concept, it makes me all warm and "fuzzy" (but just on the surface). 😄

[@Neoentrophy]

Nothing wrong with a bit of fuzz around holes

[@-_Nuke_-]

O_O

[@pranavlimaye]

😭

[@damienmcmurray9786]

Scorch the earth around the hole!

[@Super1337357]

These videos where you make his head bigger are super uncanny valley for me. I'm glad you guys went back to normal in later videos.

[@douglasdravininkas166]

How thick are the walls on this fuzzball before being "pinched off"? does this surface maintain the same thickness as it grows, or do the fuzzy walls grow in some proportion to how big it gets?

[@Anoyzify]

Planck-thick ?

[@volkhen0]

I think the vibrations on the string keep their amplitude- they just get longer (there is more of them on the string length). Isn’t it because the vibrations are “done” in the tiny looped dimensions?

[@dougscott3263]

I would believe every word this guy said if he started every sentence with the phrase " In a Galaxy Far Far Away"

[@andersjjensen]

Never believe a science guy. The definition of science was never "to be right" but rather "to be the least amount of wrong possible". Belief has no place here.

[@TheKurtisBLO]

3 weeks and no new video?!? I’m dying over here

[@theexodeus]

What if the same “fuzz ball” is what’s at the border of our universe encasing us, and we’re the singularity point of a higher dimensions black hole, and the reason our expansion is accelerating is because our black hole is consuming more matter and as such is growing in size.

[@jorgepeterbarton]

Around and back again topology of a finite universe.

[@theexodeus]

@@hyperduality2838 what

[@goldnutter412]

THERE IS NO SUCH THING AS PHYSICAL MATTER NEXT loser please ? i say no time limits debate but i have to die sooner or later or you could just go corrupting your embryo to death with the surface corruption we OH WE JUST SAW ONE HOW LUCKY OH AND CRISPR CURED BLINDNESS what are the odds.. ITS BEING LAID OUT FOR THE SHEEPLE BECAUSE THEY STILL DONT GET IT ummmmmmmmmmm kzbin.info/www/bejne/n163aKd5grp3jrc where is the half a droplet ? oh there goes 4 2 1 0 too late

[@goldnutter412]

a 7 fancy that 1 DIV 7 ? a one (______) and oh handy a 7 folding a 1 inside itself perfect numbers 2 6 42 THE END

[@theexodeus]

@@hyperduality2838 what