Is It IMPOSSIBLE To Cross The Event Horizon? | Black Hole Firewall Paradox 

15:57 So basically like that one scene from the Simpsons where Moe throws Barney out of the Bar only for him to just appear behind him?

“So you’ve decided to jump into a black hole…” sounds like the general motto of 2024.

Never name your kids Alice, The are cosmologists lurking round every corner.

A new phrase has entered my list of things that will remain in my mind rent-free: naughty qubit

"Because of the laws of physics, we cannot print an unlimited number of shirts".

I really like the firewall idea, and I kinda hope we end up finding evidence for that. It's a very cool idea to consider, that black holes are actual holes as in the space inside just doesn't exist, and it's also just incredibly funny. Like: "Our calculations say all kinds of impossible things should happen inside a black hole, but those things are impossible so they shouldn't be happening!" "Don't worry, the interior doesn't exist so those things aren't happening."

Dude, i love videos like this. I need to rewatch portions of the video multiple times to understand wtf is the abstract concept that's being explained and i realize that whoever the guy making these animations and montages is, his work is definitely ultra helpful in so many situations.

I feel like a student who skipped the entire semester but then showed up to the final lecture before the exams

I'm in Leonard Susskind's ER = EPR interpretation camp that basically says the following: - An outside observer sees the expected slowing down to infinitesimal rate of motion and dimming we would expect at the EH - If the outside observer waits long enough, they will see the BH evaporate away until there is only a stellar remnant of some sort left - The falling observer crosses the EH and notices nothing out of the ordinary; they fall further toward the singularity in time and when "reaching" the moment of singularity, emerges in the distant future at the moment the BH has evaporated, and there is no BH in existence anymore, nor a "naked singularity", just a stellar remnant of some kind (what ever is left from the evaporation process when it re-emerges from the retreating and disappearing EH - remember, the EH is not a real physical entity) - Thus, the outside observer will (in theory) after a long, indeterminate, but finite, stretch of time see the falling observer fade in again and move away from what once was a BH, while the falling observer simply will be in free fall and not ever even notice that they fell into the BH in the first place Of course, in reality, the chances of the falling observer to emerge again while still alive are slim; they probably have starved by then, unfortunately they forgot to supply an indeterminate amount of cheeseburgers for sustenance until they appear again. The outside observer will have a theoretical supply of cheeseburgers and might survive for a while, but die of boredom in the meantime.

i find alot of these episodes are a bit beyond my knowledge and intelligence but i have still learned alot. thanks Matt and crew

hello, Mr Matt, my idea for antigravity engine: The concept is based on the following principles: 1. A tokamak reactor is used to create a plasma of fusing atoms. 2. The energy released from fusion reactions is utilized to strengthen the magnetic field around the plasma. 3. This enhanced magnetic field accelerates the plasma to near-light speeds. 4. At these extreme velocities, the plasma reaches a new state of matter, where added energy manifests as additional mass. 5. This new state of matter generates a significant perpendicular force. 6. When the tokamak is charged with this 5th state of matter at a specific point, the resulting perpendicular force exceeds Earth's gravitational pull. 7. The system, entangled with the 5th state of matter, disconnects from Earth's gravitational field, effectively achieving antigravity. This concept represents a potential unification of quantum physics and general relativity, offering a novel approach to antigravity technology. what do you think?

This guy is really smart

I must not know enough about the actual definition of equivalence, it sounds like Alice's "hey I noticed a firewall" observation that breaks it is similar to looking out the window on the Vomit Comet and noticing that I'm in an airplane & not a distant gravity-less part of space.

Finally I now have an explanation for that throwaway, unexplained line from kurzgesagt’s old black hole video. Been bothering me ever since

"extra impossible" brand new expression in my vocabulary.. love it ! 😍

Can you say more about why severing the entanglement requires a high energy?

YES YES YES!! PLEASE GIVE BOB AND ALICE ENOUGH ENTANGLED PARTICLES TO EACH COLLAPSE INTO THEIR OWN BLACKHOLES ASAP!! You guys are killing it!! Thankyou Matt and crew, you guys hands down make some of the best content on here! Cheers!

I miss the answering comment questions segment at the end of a video.

Here’s an idea: The “firewall” that Bob encounters is actually/also the entire evaporative history (via Hawking Radiation) of the BH. For Alice, this encounter plays out over the long remaining lifespan of the BH. For Bob, it happens in an instant. The difference in perception is due to the extreme gravitational time dilation near the EH.

I once saw a picture of soap stretched out and a rubber band place in it and the soap surface inside of the band popped. It pulled the rubber band taut and left a hole there, and I'd wondered if it wasn't possible for black holes to be like this. Cool to see this idea come up here.

This video was way more understandable some of the previous video. Thanks for the _mostly_clear explaination!!

If it takes a firewall to break entanglement, why is our quantum computers decohering so quickly?

Thank you! Finally I understand 1) why the paradox is really a paradox and 2) why, when a seemingly arbitrary amount of 50% of the black hole has evaporated, the information becomes, in principle, recoverable. I've heard lots about this and everyone has these convoluted, esoteric explanations (even you, Sean Carroll!)

I feel proud to watch this video and not be completely confused about the topic being discussed. Matt/PBS Spacetime Crew have done a good job at building our knowledge up enough to tackle these subjects.

"Einstein halp!" 🤣🤣🤣

Infinities in the math, and paradoxes, are a sure indicator that you need to investigate and rethink. One of my profs told me that as an undergraduate and it stuck with me. Firewalls seem a good indicator that our conception of what happens to information at the event horizon begs more work

I want to thank the patrons of PBSST, because they really enable this excellent work for all of us for absolutely free, so thank you.

these recent episodes are fire.. love the content.

thanks for another one PBS team

Crazy that you're making these videos about such complex things and so many people are turning up to watch. Great job!

As always, an excellent lecture! A real pleasure. Thank you and all the SpaceTime team for your work.

I'm loving these black hole videos

Ngl, a lot of the current boundaries of physics leave me waiting for the new Michelson-Morley experiment that blows up our existing theories.

This all reminds me of something. Apparently black holes and white holes are both equally valid solutions to the math of what happens when stuff gets too dense. If it really makes sense to consider the possibility of there being a firewall so powerful that nothing can ever enter a black hole, and it just gets dimmed by time dilation from the ridiculous mass to the point that it looks like Hawking radiation, maybe we just don't live in a universe with black holes at all. Maybe they're just time dilated white holes. I mean, isn't that what a white hole is? An explosion so powerful that nothing can ever get in?

Every time entanglement is brought up, it really makes me want to see an episode where entanglement is discussed in the context of pilot wave theory.

I don't get why the astronaut seeing a firewall will break equivalence principle. It's like saying someone falling into Earth's atmosphere feeling herself burned into plasma is going to break equivalence principle.

So electron flying through both slits simultaneously fits perfectly into quantum theory, but a qubit being on both sides of the event horizon somehow ruins it?

I don't quite understand why the firewall would break the equivalance principle. Doesn't the surface of a planet act in the same way? It's just a physical barrier as far as I recon, which doesn't interfere with the spatial properties around the black hole. What am I missing here?

I’ve been waiting for you to talk about this. All the current pros studying this all say they have a firewall.

Excellent video Matt and team, keep the hard work.

What I always asked myself is whether Hawking Radiation completely throws the possibility of falling into a black hole off the table. Since it is said that a black hole will evaporate in a *finite* amount of time, wouldn't that mean that the time dialation near the event horizon can become so great that the actual black hole would shrink just before one would enter? Would that also imply a trip to the vastly distant future where the black hole completely evaporated, or became small enough to tear the traveller to pieces?

The thought that spacetime doesn't exist "inside" a black hole is eerie, but also beautiful in a way

How I understand it as a non-physicist is: - from outside point of view, anything falling into the hole gets slowed down indefinitely and appears stuck at event horizon - from falling point of view, you fall as normal but the outside time speeds up indefinitely Then assuming hawking radiation exists and can be measured from outside: - from outside point of view, for a big enough hole, it's very small and barely detectable - from falling point of view, you get ever increasing radiation levels (as time speeds up) and upon reaching the event horizon you receive ALL the radiation emitted by black hole in your direction through it's entire life. Obviously nothing can withstand such radiation levels and is just torn apart and radiated away without ever reaching the inside

Another thing worth revisiting is the kugelblitz video -- how does this work if a black hole forms around you, rather than you falling in? The space disappears? Does it happen faster than the speed of light?

14:22 huh, so it's like a literal hole in space time, a "black hole"

Purely as a layman, it makes me wonder if the firewall is equivalent to the holography argument ie. the firewall is the 2D manifestation of the blackhole's 3D interior. I guess a region in spacetime where the fabric becomes so distorted space behaves like time and vice versa, would probably have some odd properties like violating equivalence. But again, way out of my depth a few videos ago lol

I hope someday Matt does a video on the Wheele-Feynman absorber theory and how it relates to soft photons

i love the idea of the best theoretical physicist just sitting there like. WHERE DOES THE POOP GO! just entire careers centered around trying to decide if information is duplicated or eradicated and which laws of physics theyre willing to accept breaking.. then just landing on I DONT. EFFING. KNOWWW.

8:50 "Without entanglement there is no space" seems to refer to Leonard Susskind's (and someone else's, Maldacena?) theories relating entanglement to the "spatility" of space. I would love to hear PBS Space Time do an episode on this, it seems like exactly the sort of explanation you are good at.

How would the firewall explain the very formation of the black hole? I mean, it's technically possible to make a neutron star very close to the mass of becoming a black hole, and then trow a few more neutron to transform it into a black hole, where does all that volume, information, mass, energy, disappear, if the space-time itself stop existing? And is it instantaneously, like all the quantum information of all the particles that were making the volume just before it turned into a black hole, suddenly appear on the event horizon? Also, I'm still not sure I understand the whole particle-antiparticle hawking radiation, like AFAIK, both particles and anti-particles have mass, then how come the mass of the black hole gets smaller and smaller as it "eats" those particles? And, if something crazy like negative-mass particles exists, how they decide to only go inside the black hole and never in the hawking radiation? Or is simply a matter of energy, like if this firewall exists, it takes double the energy to break a virtual particle pair, and then half of it goes outside.

Interesting as usual. Thank you!

"Extra impossible" is now my new favourite expression. ;-)

1. If nothing can cross the firewall, then how does a black hole gain mass? 2. What about when black holes merge? Clearly, the event horizons do cross, which would means it MUST be possible to cross the event horizon. In these events, wouldn't it be possible to see the bulk of the material in the accretion disks being annihilated by 2 firewalls? 3. Further, how is this ridiculously powerful energy field being created? What mechanism (that no one has ever measured/seen/theorized before) is creating it? This episode seemed to explain everything in more comprehensible terms than usual, yet, I'm more confused by the subject matter somehow. A TRUE information paradox... :)

So, where this black hole firewall take the energy to power up a giant screen of death for octillions of years? Because this sound to me like a quite promising energy source.

Crazy to think it wasn't all that long ago that even the idea of black holes didn't exist yet. Now we're trying to untangle their mysteries and coming up with theories like these.

While I wasn't a fan of Antman: Quantumania, I do appreciate how the many of the visuals and concepts they dealt with mirrored actual scientific happenings described here. Appreciate them doing some homework👍

Spacetime itself is an evaporating black hole.

For a stationary black hole, it would appear to you that you never fall through the event horizon, because any light that has fallen in further than you can never reach you, but the mass can still lense some light to you, as long as that light hasn't yet fallen in further than you. So to an object falling into a stationary black hole, the black hole would appear to shrink away from it, all the way up to the moment when it reaches the Roche limit and the tidal force renders it to quarks. But stationary black holes probably don't exist.

I absolutely agree about our theories being broken. And not only because of this... Either way, I hope someone can solve this conundrum soon. But I wouldn't hold my breath.

It’s always the edge cases that get you.

Best channel next to Fraser Cain, SFIA, Cool Worlds and SEA

Don't touch the edge is the galactic version of don't drop the soap.

That intro was top tier

Great vid as allways, top content

Just about every Black Hole Information Paradox video on RU-vid seems to forget that: 1) From the outside observer’s perspective, it takes a falling object infinite time to reach the event horizon, but meanwhile the bh is sloooowly evaporating as Hawking radiation, so the latter process will finish first. And therefore 2) Due to time dilation, the Hawking radiation looks like an explosion of gamma rays to the falling object’s perspective. If that observer survives the Hawking gamma storm, it will still see the black hole radiating away all of it mass and vanishing before it gets even close to the event horizon.

"A lot of energy is needed to break entanglement" Okay, but need and exists is two different things. As presented on the video, there is no explanation to where this necessary energy would come from. It doesn't seem to be emerging from the theory itself and rather being "there is a firewall because a firewall would solve this problem"

That point about the singularity expanding to the event horizon gave me a few ideas. Half of what's on this channel goes over my head without a repeat watch, and these ideas might have already been addressed or shown to be impossible with info in other videos I don't remember, but who knows. What if a star/stellar mass collapsing into a black hole is it crossing over the breaking point of a sort of "quantum pressure", not to dissimilar to protons turning into neutrons in neutron stars or even neutron stars into the theoretical "strange stars", where "normal" matter goes from being in a defined yet unknowable state, to being changed into some other, new phase of matter where all possible quantum states are "filled"? In this case it could be not that the forces within the event horizon get even stronger towards the center, but that the body of the black hole is a sort of homogeneous and equal density of "full" space-time, possibly where there is no "real" distinction between the center and near the edge of within the event horizon, and new quantum information flowing in is not destroyed, but is altered in a way that it can cram into an un-claimed quantum state. Given the existence of things like the "Planck Length" and "Planck Temperature", this says to me that all cells on the spreadsheet of quantum information have defined ranges, and therefore, every point of space-time has a defined amount of possible quantum states, and those quantum states could be crammed full by the absurd amount of energy in the process of a collapse. And on top of this "state-cramming", given the sheer energy required in neutron stars to convert protons, and even vastly more energy for that "neutronium" to turn into the theoretical "strange matter", I don't think it's that far off of an idea that the collapse into a black hole could cross this energetic barrier to transform into this new state of matter, possibly one beyond anything we can concieve as of now. A bit of a long shot, but as an extension of this, in regards to hawking radiation and evaporation, is that conversely to the (to my knowledge) typically un-entangled matter that adds to the mass of the black hole, in the pairs that form near this boundry, the in-falling half bounces off of the surface, alters one of the taken quantum states on the surface (like how observing a particle changes its information, the thing that makes it never fully knowable), and that which it interacted with cannot change into one of the other quantum states taken within, so that information which *has* to change because it was interacted with changes into an information state that is available, and the only available states it can take are *outside* of the event horizon, thus performing the process of evaporation. Think of it like the "death by 1000 cuts" but it's "Death By Eleventy Bajillion Hawking Pairs Tea-Bagging The Surface Of The Black Hole". Another way this could work is that (some of?) the information of the in-falling particle could be in a way "locked" by the escaping particle, destructively (to the black hole) interacting with this "full" matter on the surface, causing this same "nowhere to go but Out" effect, causing of these occupied states to change in a way that forces it to superposition/tunnel to the other side of the event horizon. While this my not be the most accurate descriptor, in this theory, the black hole doesn't destroy information, the black hole IS the information. I spent over an hour writing this comment and re-writing and processing this all, it's almost 4am, I would like a cookie and some sleep now please.

I love these dense episodes

We don’t enter the black hole. The black hole grows around us. We are frozen there until the end of time, or when Hawking-radiation disintegrates us. Side-note: it resolves the information paradox.

You already cannot cross it. In the reference frame of a distant observer, you take forever to cross it, that is not an illusion, you just asymptotically approach it. So you either take forever to cross it or hawking radiations if real destroys the black hole before you cross it. From your falling perspective this time is finite, but the black hole evaporates before you enter it, or if you enter it, there is no outside anymore, because infinite time has passed outside.

I would love to watch an episode about black holes in the context of string theory.

One thing I've wondered for a while about black holes, and maybe some of you can clear up this confusion, is: Since time stops at the event horizon (for the outside observer), if you fall into a black hole, the outside observer should "see" you simultaneously hitting everything that's fallen in before you, and being hit by everything that'll fall in after you, exactly when you cross the horizon (which he'll never actually see because 1) it's in the infinite future and 2) redshift; but it seems to me that that's the correct extrapolation from what he does see) Doesn't that mean that while you fall in, you'd in turn see the outside universe speed up, getting UVshifted to the point where it annihilates you as you get close to the horizon?

I am not convinced there is a paradox at play here. If i sat a qubit on my desk and put a mirror across the room from it, i would be able to see the qubit by looking both directly at it, and by looking at its reflection in the mirror. No one would claim the qubits been duplicated - i can just either look at it directly, or at an image if it. In the same way, when the qubit falls into a black hole and the last light to interact with it gets caught in the event horizon, im not look at the _actual_ qubit on the event horizon. Im looking at an image of it in the very last moment before it passed the threshold. Edit: heres an analogy - say i was on a spaceship orbiting a black hole, and im holding some object, but i have my eyes closes and have no idea what it is. I throw the object in, and once I’m good and sure its passed through the event horizon i open my eyes, look and the event horizon and see the object was a lit lightbulb. However, the object was actually a flashing lightbulb. If i was inside the black hole id be able to look directly at the lightbulb and see this additional piece of information, but since the impression caught on the event horizon is just a snapshot of the object, the information is lost to the outside world. To me this busts the paradox - the actual nature of the object would continue to exist below the event horizon, but would not above it.

Who wants to be the first to find out? 😂

I wonder idk like 2years ago, about similar thing. That is "probing" (so to say) black hole with entangled particles. I know that it is not really the same stuff as described in this video, but still. I'm kinda happy I came up with it before it was published on PBS. Btw lovely episode!

I always thought that Hawking radiation itself acts as a firewall, due to time dilation. If time slows down for an outside observer, the it speeds up for the inside observer.

Thanks for this episode which I have been asking about for years now. The comments are asking about how the firewall is spontaneously generated in the first place. In my opinion, and keep in mind that all astrophysical (actual) black hoes are rotating, if spacetime is thought of as 3D surface tension of a 4D fluid, just for argument’s sake, then once a black hole forms, say from a collapsing star, the angular momentum of the star is retained and the vortex keeps going so much so that there is substantial interstitial shear at all elevations in the black hole. This shreds spacetime so that it’s effectively quantum foam but macroscopic. In my opinion, the firewall solves these paradoxes and will eventually have to drive theoretical physics to these same conclusions. It doesn’t even break GR, it’s just an expansion of it.

So good to have my mind completely blown. Quantum entanglement creates space.

That new merch tee is fire. Er not actually fire. Looks like collider activities that I totally understand

I've always been attracted to the idea that a black hole is basically a very high energy elementary particle. I don't know enough physics to know if that is at all sensible. I made it barely through quantum II in college. But in my lay opinion, I always liked the idea. I really wanted to take GR but was told that there was no way I could handle the math and there was no sense in auditing the class if I couldn't do the math. I really wanted to audit the coass though.

I'm love'n these black hole videos 😊

A bit of a tangent, but an insightful tangent appears when one appreciates that at the Event Horizon, there is a steep gravitational gradient. Gravitational gradients (steep or not so steep) affect local timekeeping. In the Hawking Radiation scenario, the pair of virtual particles are maximally entangled, meaning they are oscillating at their characteristic de Broglie frequency. At the instant of the birth of a pair of virtual particles, they are jointly oscillating in perfect phase-locked synchrony. But as they separate along the black hole's gravitational gradient, they drift out of phase with each other: they necessarily decohere with their increasing separation distance. Now apply that same thinking to a pair of entangled particles (or qubits) in a Bell test experiment. Due to the ubiquitous presence of gravitational gradients (e.g. those affecting the Earth's tides), the Bell test particles also drift out of perfect phase-locked synchrony; they ineluctably decohere with separation distance. Bell left this phenomenon out of his mathematical model, assuming that timekeeping was uniform along the axis of separation. If you add gravitational gradients back into the underlying model for the derivation of Bell's Inequality, you don't get that his presumptive hidden variable, λ(x,t) is an odd-function, integrating to zero. Rather you get a non-zero "beat frequency" term arising from taking a gravitational path integral. This discrepancy suffices to explain why the Bell Inequality doesn't apply to time-varying (oscillating) characteristics in a cosmos suffused with gravitational gradients. The not-so-hidden variable is time itself (and any characteristic (like phase of the de Broglie wavelength) that is a function of distance and time. The (essentially random) phase of the Bell test particles suffices to explain why Bell test experiments do not obey his inequality, due to decoherence arising from differential timekeeping, thanks to gravitational gradients.

13:35 "... Alice could descent very close to the event horizon to see that there is a firewall" --> If the firewall is exactly _at_ the event horizon, Alice actually can't see (or otherwise observe) that there is a firewall. It's just as inaccessible as for further away situated observers.

You've got me curious about a possible connection between event horizon barriers and those perhaps lesser barriers at the limits of a solar system, or even potentially of a star or planet (like ours). Thank you for the "food for thought."

"[firewalls] makes it extra impossible to even think about observing the same qubit both inside and outside the black hole" 11:20 we've been thinking about it all episode, so we know firewalls aren't real.

This show has top rated talent.

I still think that the best solution is just that nothing ever even reaches the event horizon. What a distant observer sees, objects slowing as they approach and then being frozen on the horizon, only to eventually evaporate away with the whole back hole as Hawking radiation over aeons to come, is what actually happens. From the perspective of an infalling observer, time around them speeds up and they see the black hole evaporate beneath them as the aeons fly by in an instant, vaporizing them in a blast of Hawking radiation and scattering their particles back out into the universe (where they form the very Hawking radiation that more-distant observers see).

We're already in one. The moment we crossed the EH was our "big bang."

Something that I never understood is that 2 things related to the firewall paradox is exactly what I would expect to see even from the most basic description of black holes, and yet I've never heard someone mentioning them: -firewall: if from a distant POV I see the BH evaporating in a finite time, and from that same POV I never see alice crossing the EH, doesn't that mean that also from Alice POV she never crosses the EH? And if we see the whole mass of a BH evaporating in billions of years, shouldn't Alice see the same mass evaporate in just the few minutes/seconds of her fall? Isn't this a powerful firewall? -"the interior of the black hole might not even exist": if from a distant POV the BH evaporates in a finite time, shouldn't it also evaporate from Alice POV in a finite time? Shouldn't it evaporate from any reference frame, included any reference frame of any particle falling into the black hole? Doesn't tha mean that a Black hole evaporates before even forming? Or maybe that just before turning into a BH, the matter falling into it "evaporate"? No BH => no paradoxes. An this would not violate our observations because from a distant observer, an object that is *almost* a black hole would be indistinguishable from a "complete" BH. Does someone know where this logic is wrong?

I don't see the problem with the idea of the singularity "expanding" to the edge of the event horizon. Isn't that basically just what happens in our external view of the singularity? The mechanism behind gravity is the warping of spacetime - effectively contracting the space around a large mass in a way that creates a lens for outsiders, but is basically unnoticeable for those passing through. So what's to say that the "event horizon" isn't just the lensed singularity, warped so large that it **looks** like it covers vast distances, despite being miniscule - and the "fire wall" is just the mass itself. So someone falling into a black hole wouldn't notice anything strange beyond the black hole looming over more and more of their vision until they suddenly ran into a mass - that's so much denser than a neutron star that the concepts of heat and black-body-radiation barely means anything as we know them - and subsequently splattered all over it. But defining the difference between such a hyper-lensed singularity and an actual "there is exotic space within" black hole sounds like the sort of task that needs someone that can finagle field equations more than I can. It may just be the layman in me being more comfortable with normal spacetime getting scrunched to an extreme extent than the exotic timespace that's supposed to be in black holes, but it also sounds like it's the simpler theory with much fewer things to invent and questions to answer.

The interior of a black hole might contain a "star" made of quark-gluon plasma, rather than a singularity as is traditionally assumed. Some physicists have proposed that the cores of neutron stars might already contain quark-gluon plasma, due to the incredibly high pressures and temperatures inside these objects. I'll take it one step further, if a neutron star were to collapse further and form a black hole, it's possible that the quark-gluon plasma would be preserved and might even play a role in shaping the internal structure of the black hole. Given that quark matter is already thought to be much denser than neutron matter, it's not unreasonable to think that a quark-gluon plasma star inside a black hole could be thousands of times more dense than a neutron star, if not even more, which would account for the extreme environmental forces.

I'm in the Fuzzball camp. Strings merging and expanding to the horizon is a simpler/parsimonious explanation that removes the need for a firewall. A fuzzshell would be this "firewall", it also removes the need for a singularity, it also explains through fractionation why BH get bigger with more engergy/mass, also explains how info could be maintained and reemmitted as hawking tradition, also provides a smooth transition from neutron degeneracy in neutron stars to BH (which could be called black stars or string stars), also provides a "horizon" on which a holographic universe could unfold. Altogether of all the theories I've reviewed it seems to be on the right track more than any other. It also has the potential to be tested on the astronomic scale by examining variations in gravitational waves and other observations (verifying quantum string theory at the same time).

I kinda like the notion of there not actually being a singularity and there is actually some layer of "normal" space deep inside where the object that collapsed could reside, along with any matter that fell in. Though honestly, the accretion disk itself is enough of a firewall.

I love this channel! I consider myself a midwit: I'm interested in mathematics and physics and willing to put in quite some time, but my IQ is too low to keep up with uni lectures. So this is - besides Veritasium - exactly the amount of information I am able to process at once. Thanks a lot!

I always learn faster when the boss music starts.

Whenever I learn that there's something we cannot explain I think of fish in a pond. The fish do not know of the desert or the sea. We have become fascinated by Black Holes, like pond fish seeing dry land.

Great video, as always, but can you guys consider getting a teleprompter that is attached to the camera right above the lens? That way it would look like he's talking to us, rather than slightly off screen to the right of the camera? I know they make those and this isn't the type of video that works better not looking at the camera. Just a suggestion, thanks!

Thank you for making BH videos. The more the better And please more neutron stars 🥳

Cheers from the Pacific West Coast of Canada.

I keep hearing the AMPS principle as the "ants principle" and I keep trying to imagine the role ants play in the quantum studies of the black hole