A "metaphysically terrifying” look inside black holes | Janna Levin

[@dylanconner8167]

I love black holes. There is literally nothing else more extreme that we know of, both terrifying and amazing. An absolute existential dread. I reeeeaaally hope I'm alive to see us fully understand them, they're what got me interested in space as a kid!

[@24k-n6x]

I felt the same, till i realised that this type of science is based on belief and not actual knowledge. We know about black holes only by these people that claim to know. Its a dogma, the space religion. Nothing different than medieval roman catholic church.

[@aarshsingh5936]

Me too

[@silvermainecoons3269]

@@24k-n6x. Uh no. You don’t understand the scientific method. Physics, astronomy, cosmology and every other scientific field has data and evidence backing up the theories. Just because we don’t understand everything yet does not mean we can’t trust the data we do have at the moment. It’s nothing like religion, it’s not dogma and it’s not something we have to just accept because of faith. There’s usually only two reasons people leave comments like yours, religious indoctrination or belief in conspiracy theories, or both. Which one are you? 😂😂

[@imladenov8238]

@@24k-n6x one of the most moronic comments i've ever read

[@kingblue3171]

I would say Vacuum Decay is equally as fascinating and terrifying as black holes

[@kielvostro]

I thought when we enter the black hole we can go to Murph's room and touch the books?

[@dr.j3685]

And say stay

[@jamesshore3191]

Only if its being manipulated by ascendent humans capable of observing and manipulating time/the 4th dimension.

[@westerling8436]

No, that's Inception

[@starxpowerxx]

@@westerling8436interstellar genius

[@jamesshore3191]

@@westerling8436 Incorrect.

[@journeywithin9155]

“Energy cannot be created or destroyed on transferred” so maybe all the consolidation of matter or energy ends up so packed that it explodes on another side, perhaps another dimension, and creates its own universe like a Big Bang.

[@NastyCupid]

A fun hypotheses, but you still have an infinity paradox on your hands with that theory, i.e. was there a primordial black hole? If so, what created that one?

[@ErnestoSun]

Very convincing. We are pretty sure within a black hole. Universe is not eternity, just part of it. Eternity is cascades of universes.

[@greyMvtter]

@@NastyCupid could there ever be any way to escape that paradox tho? are there any other theories that come close to explaining it?

[@asiremu]

Don't mind me, just commenting to see how this comment section evolves.. Everyone's comment here is very interesting :)

[@abebeRed95953]

Energy can be destroyed during neuclar reaction

[@ryandubyah2345]

This is easily one of the best videos of this nature that I’ve watched. Factual, clearly spoken and NOT by a robot voice. To the point. I really enjoyed this one, thank you!

[@-TheMaskedMan-]

Yes, it’s explained very well and it sounds as though I was listening to a good story.

[@privaterizk4936]

Well, it's BigThink. You can actually expect more. It's one of the channels that I rely for some knowledge.

[@chrisstevens-xq2vb]

@@privaterizk4936So you think infinite density bending nothing without force is science?

[@mrb2349]

Yes, I hate the so-called science channels which have AI written scripts, stock video clips and text to speech narration.

[@denzeldl]

You can also find these black holes in between the seats of your car. 🕳️

[@nizamieminov3648]

Lol😂

[@hekalkal8111]

THERE IS ALSO A PINK HOLE.😜😜😜

[@AlexDeLarge1]

And your couch, and sometimes they just pop up randomly and things are just gone.

[@3PhaseSparky]

all my socks are in a black hole somewhere

[@hekalkal8111]

@@3PhaseSparky 😁😁

[@michaeldebidart]

I recently came across a Nova documentary about black holes hosted by Dr. Levin and I was instantly drawn to her charm and enthusiasm. I’ve been reading up on her and to echo a comment on another video, if intellectuals were as celebrated as movie stars or athletes, she would be an absolute legend.

[@Aviator27J]

From what I understand (and I've only taken two upper level astrophysics courses), she's describing black holes from the point of view of relativistic physics regarding singularities. Relativity (specifically general relativity) says a black hole is infinite density in infinitely small space (or as she rephrases, is no longer space at all), but quantum physics requires a finite number, a specific definition of density and spatial dimensions. It has to be a point with measurement on some scale. Of course, one issue in physics is that quantum mechanics is the most verified, most exact aspect of physics we have, and while we're sure Einstein's relativity isn't complete, it's also very well proven on large scales (particularly velocity, gravity, and their relationship with space-time), yet we can't get quantum and relativistic physics to meet. In the very large, we use relativity to a very accurate degree; in the very small, quantum measurements are extremely precise. Where they meet, we can't yet resolve. So in that way, her description of black holes as infinite singularities makes sense, but it isn't the only way to view them.

[@quarky37]

the habitual conflation of physical principles with mathematical principles is surely one of the greatest blunders of popular science communication

[@steelersgoingfor7in2024]

Why do we label anything to do with unknown science absolute? Aren't we always pleasantly surprised when we are proven wrong time and time again? We "know" that most of the universe is invisible to us, and what our instruments detect that our eyes can't are parts of it. Not all of it. Imagine seeing the complexity of it all. Could we only be seeing a miniscule part of an unfathomable process and are just labeling it a black hole? Remember, we all see through the lens of human experience. Surely, we aren't the most complex parts of it all when we encircle every theory within the confines of a human skull. The truth, I believe, is unattainable until we learn to think outside of brains. Whether that is evolution or symbiosis or something we are yet unaware of. It may very well be that we are similar to cells under your fingernail trying to figure out what that shitty smell is every so often. 😅

[@tgdm]

There's also one of the competing concepts of the "dark star" description of black hole anatomy which postulates that while the event horizon exists and spacetime around it behaves the same as described, there is a physical object just beyond it instead of an infinitely dense singularity. The declaration here being that there is a finite amount of stress gravity can exert on matter and the object is more akin to a quark or strange star and it cannot be compressed any further.

[@714_Lucifer]

my issue with quantum physics as a whole is that there is zero experimental evidence to support it. we can do the calculations and make predictions all day long and see that the math adds up beautifully, but we haven't been able to find a testable example yet. My issue with the relativistic view is that density simply cannot be infinite. unless this suggests that the "infinitely small space" is constantly obtaining more density... and how can something be infinitely small? I agree with someone else's comment in that we use infinite far too loosely. almost like it's just an easy explanation to say something is infinite because we can't comprehend the nature of it

[@tgdm]

@@714_Lucifer Hold up, are you saying "zero experimental evidence supports it" in reference to the concept of a black hole and/or singularities with infinite density, or are you aiming that at the entire field of quantum physics?

[@artdonovandesign]

I got Dr. Levin's book as soon as it came out. It's fantastic! REAL physics- not dumbed down yet eminently understandable to the non-physicist. I came to know of Dr. Levin from her memorable segments on the PBS 'Nova' episode, "Inside Einstein's Mind" - which is a MUST WATCH. It's one of the finest physics/science specials you'll ever enjoy. Best to All. 😊

[@BillyOrBobbyOrSomething]

There is no “real” physics without the math my friend. Definitely a great book though

[@ronjon7942]

Thanks for the recommendation of her book, and the episodes. I’m always looking for new perspectives. Well, different perspectives, anyway.

[@quantumxfluxmd6821]

Blackholes were one of the main things as a child that got me so heavily interested into astronomy and physics. Coolest object or "place" 😉 ever.

[@jayp7385]

As a child and beyond, I had always believed black holes were essentially portals to other parts of the universe.

[@kryts27]

Nearly, but not quite true, There is Hawking radiation.😊

[@abhirupkundu2778]

i used to study about black holes as a child@@jayp7385

[@jakel7213]

​@@jayp7385I mean in a technical sense, it is. Past the event horizon is a "place" that is causally separated from our universe.

[@hpwilliams0]

I read Death By Blackhole and was hooked!

[@duprie37]

It helps to think of the singularity as an event in the future rather than just a place in space. There's no escaping that point just like there's absolutely no escaping the fact that you'll reach next Wednesday 2PM no matter what you do. You're drawn inexorably towards it, travelling there through time at the speed of light in fact (if you're at rest with respect to space). Moreover, next Wednesday 2PM you'll be at a specific location in space also and likewise, no matter what you do you cannot avoid arriving at that location whatever it turns out to be: true you may get a choice about its geographical coordinates, but it has to be _some place_ in spacetime & that _some place_ is absolutely where you'll find yourself 2PM next Wednesday, just like it is with a singularity.

[@ShadeAKAhayate]

Indeed. The only thing I'm uncertain of is if the time to reach the singularity would actually be a finite one. Especially in a rotating black hole with its internal horizon, ringularity and stuff.

[@saulgonzalez8558]

Man you stated that beautifully, great perspective

[@thomassturm9024]

The fact that you will leave next Wednesday 2PM as well makes it a little less scary though. And I'm saying this even though I have a dentist appointment; so maybe not all parts of me will be leaving next Wednesday 2PM in the same direction.

[@duprie37]

@@thomassturm9024 Presumably you could leave the singularity too, if getting there didn't kill you first by blasting you to infinity (as far as we can say, although that's probably not what actually happens, because: infinities). The singularity is analogous - I guess - to that point in your future spacetime worldline at which you die. That is also a kind of singularity, for your subjective consciousness in any case. It's where spacetime ends, for you. The singularity of a black hole is where spacetime ends (allegedly) for the whole universe.

[@MichaelNiles]

As someone who fancies black hole cosmology, the heat death of the universe seems like a pretty good explanation for how you arrive at the end of time, at the singularity. When no more information can be exchanged between any two bits, when no more change can occur, time ceases to be.

[@justicegear85]

I really liked the part where she says “the black hole is like a lens”. It offers you additional perspective that has been otherwise never really explained as such. Very nice.

[@jeffreyraia]

Thank you for taking something so complex and putting it into layman's terms.

[@A.G.P.115]

Yet this is our best understanding of blackholes.

[@matttzzz2]

Like every other video on black holes

[@elypowell6797]

@@matttzzz2 I know right! She didn't say damn thing that hadn't already been said a million times plus she looks like an activist. They just prop this women up because she is a she! One lady scientist who I believe is the real thing is Sabine Hossenfelder. It would be interesting to hear her take on black holes.

[@Goldtech6973]

Who are you thanking? This material has been shifted from one channel to the next.

[@victorhansson3410]

@@matttzzz2thank you! I don't understand why authors don't speak of concepts relevant to their actual demography.

[@Doug7RM]

I envy people who can see a set of equations with symbols I don’t even know how to pronounce… and instead of seeing symbols they see black holes and stars and space… truly remarkable.

[@barnazadori9227]

Yeah, they're like Neo seeing the matrix as it is. Codes.

[@BatMan-oe2gh]

For them, those equations are a language, like music is.

[@KenSherman]

🔤🔢🔡 🔢🔡🔠 🔡🔠🔢

[@Arkhs]

It's just language. You are seeing these symbols making up words right now and forming the concept in your head right. Maybe even visualising it. It's the same as any other language, you immerse in it and it becomes easier to understand. The difference is that it's a better language that is exact and precise.

[@modallas8034]

I couldn't put it better. 👍🤪👍👍

[@elmo2you]

Great story telling; great personality and charisma too.

[@sammyf0x]

What a calm and soothing explain, suddenly i feel all my problems are so trivia

[@robertd9850]

But they're not! Panic now!

[@Vijay-b4o8b]

Science of the highest order explained with simplicity. Good video 🙏

[@takasmaka820]

7:16 thats wrong matter is still there because Black Hole can gain mass and grow!!!

[@oliverbyrne3209]

This woman explains it more exquisitely than I've ever heard.

[@ChrisQuirk-p2w]

Yeah she’s great. I’d love an hour of her talking about this in detail - time dilation - gravitational lensing - relativity from different perspectives - photon POV

[@mikehenrys]

Who knows if she had help in figuring out the best way to present it?

[@judkilgore3822]

Her book Black Hole Survival Guide is fun and fascinating. Levin’s writing makes BH science understandable without being overly simplified. It’s one of the best gifts I’ve received in the last several years.

[@nicolasnicolas3889]

Here's some physics I would like answering since I don't have a PhD in physics. If the escape velocity of earth is 7 miles per second how can aircraft get off the ground when gravity is apparently much stronger at the surface than farther from it with the inverse square law? Also if the earth moves through space at 60000 mph and escape velocity is apparently (see my previous question) only 25000 mph, then surely to launch spacecraft all we have to do is 'jump off the back' of the earth and it would fly away at near 3 times the (apparent) velocity needed to 'escape' the 'gravity' (gravity is after all still just a theory) and also have quite a good clip going on, thanks! ;o)

[@takasmaka820]

7:16 thats wrong matter is still there because Black Hole can gain mass and grow!!!

[@usmh]

The interesting thing about black holes is that they're "nothing..." but nothing doesn't exert gravity. If all matter that enters is changed into non-matter, then the black hole can't exert their power through a particle, like the graviton for gravity or the photon for electromagnetic radiation. So what "drives" black holes?

[@nunya2514]

I was thinking the same thing. If gravity is based on mass, and mass is based on matter, density, and size, then how does nothing create or have gravity? Especially, black hole level

[@packetcreeper]

I could listen to Dr. Levin talk about black holes all day. Such a fascinating subject and I highly recommend her book 'Black Hole Survival Guide'.

[@billthompson4718]

Oh dear. Thank you for trying to explain to non mathematicians the basics of a black hole. Excellent job! Even though just like I can’t repair a tv because I don’t have the technical background, I will never truly understand the ‘why’ a physicist can say what they say . But, in the end, just like I have confidence in my tv repair person, your observations ring true. Thank you for posting this lecture.

[@hosoiarchives4858]

This is one of the poorer explanations available.

[@musicman0423]

I’ve always thought of black holes as the “stuff” that makes up the outside of our universe. For example, if you take a regular rubber birthday balloon and wet the inside and tie off the end, then you try to stretch it out into a sphere, it’s impossible. Unless you poke tiny holes that allows air to replace the space that’s created during expansion. Maybe black holes are the holes in our ever expanding balloon. I know that’s not what scientists think, but I’ve always thought it was a cool idea.

[@sasca854]

0:40 only if your frame of reference was that of something falling in with the sun, or a frame comparable to it. From any other frame of reference, the sun's collapse stopped precisely at the moment the horizon formed, and that's where it will always stay. You just can't see it because light is quantized (comes is discrete chunks), and therefore there must necessarily be a point during the collapse where the next photon emission is infinitely far in the future. But it _is_ there. It's not a question of optics or visibility, either-- you could calculate where the surface of the sun is and use AR goggles, for example, to interpolate a synthetic image onto the horizon to give you a visual representation of where it really is. Furthermore, it's not just the star that is frozen at the horizon-- anything and everything that has ever "fallen into" the black hole is still _right at_ the horizon, just infinitesimally short of crossing it, in a freefall that will literally take forever (from our point of view). This is the real reason why you cannot "turn around" once you, from your frame of reference, cross the event horizon. To come back means you would have to have entered in the first place, which is an event that never occurs in the frame you're trying to get back to. It's problem of fundamental causality. The two co-existent yet causally disconnected frames of reference I just described are what we call "black hole complementarity". And for the record, this is just the tip of the iceberg on how weird black holes truly are.

[@stroon9855]

not only did your channel get much better (thous it's alwasy been super interesting), but the music did get as well! cool!

[@greenrx3744]

Such a fascinating discussion.

[@noelwass4738]

This is such an excellent talk about black holes, I have never heard such an excellent talk about black holes.

[@brandonmayo4063]

This is a very good video. She explains it very well.

[@92526abs]

did a science project on black holes in highschool. always loved astrophysics and the mysteries of the universe. fell out of touch with this topic for years, stumbling onto this and recalling just how utterly helpless we are compared to the infinity of the universe. felt the existential dread as i followed along her story, like i am literally approaching the singularity and will fade out of existence. all the meaning and beleif systems collapsing like the star. its truly terrifying and terrific all in one.

[@frinkledinkjones]

the visuals in this are insane

[@Abmotsad]

Brilliant content, brilliantly delivered. I would love to attend one of Dr. Levin's lectures.

[@talananiyiyaya8912]

No you wouldn't

[@Abmotsad]

@@talananiyiyaya8912 Oh dear, how silly of me.

[@Matty_Ice87]

I loved this! I excellent work!!

[@hybridwafer]

We know that black holes have mass and the more mass that falls in, the bigger it becomes so the mass or energy exists in there and is quantifiable. I never understood why it would be more likely that there's a singularity in there rather than a finitely dense state of matter that can't collapse any further.

[@jamieostrowski4447]

I don't see how it could be nothingness, either. As the star collapses, I can see it becoming infinitely smaller forever in terms of volume, perhaps approaching a singularity, but never becoming a true "point".

[@vaettra1589]

@@jamieostrowski4447 Yeah since black holes grow when feeding, wouldn't it suggest that matter/energy falling into it, don't leave this universe? The more matter it devourers, the bigger impact it has on its surroundings. If the matter would just cease to be, it wouldn't affect the surroundings.

[@V_for_Vendetta_]

I have a theory that maybe black holes are the region of a specific universe where time flows back wards. This is evident by the fact that light itself cannot escape it. . . . . Surely, there is no way of knowing what's really inside one, But in a gran scale of multiverses, it only makes sense that time [one of the many dimensions that we experience] has its very own counterpart---- backward flow of time.

[@jalontf2]

Just call it a neutron star but like 500x the density

[@Sartorri4666]

I'm with you. There is no such thing as "nothing" as she claims. A black hole is not a hole, it's a big drop of dark stuff that's so dense light gets trapped by it's attraction.

[@MeissnerEffect]

Ms Levin, a champion astrophysicist!

[@WBenzSEL]

Really good explanation - most interesting objects in existence in my opinion

[@Sartorri4666]

Definitely the most attractive.

[@Philomats]

That was well explained. This will be food for thought for me for quite a while.

[@dudemantype]

But, as you fall into a black hole, if your clocks slow down relative to an outside observer, theirs speed up for you. So as you approach the singularity, you will see the end of the universe... and onwards to infinity... right?

[@kanwaljitsingh3248]

Thanks a lot dear lady for this excellent video.

[@farrier2708]

Spike Milligan exquisitely told us how to fly and it explains perfectly how things stay in orbit. "You simply throw yourself at the ground ...... and miss."😎👍

[@nicolasnicolas3889]

Here's some physics I would like answering since I don't have a PhD in physics. If the escape velocity of earth is 7 miles per second how can aircraft get off the ground when gravity is apparently much stronger at the surface than farther from it with the inverse square law? Also if the earth moves through space at 60000 mph and escape velocity is apparently (see my previous question) only 25000 mph, then surely to launch spacecraft all we have to do is 'jump off the back' of the earth and it would fly away at near 3 times the (apparent) velocity needed to 'escape' the 'gravity' (gravity is after all still just a theory) and also have quite a good clip going on, thanks! ;o)

[@farrier2708]

@@nicolasnicolas3889Aircraft are a totally different animal compared with spacecraft. Aircraft are literally sucked into the air when the suction over the upper surface of the wings is greater than the weight of the aircraft. Orbiting satellites are falling directly to Earth under gravity but because they are travelling sideways, they miss the planet and travel around it. Escape velocity is the speed at which a spacecraft will not only miss the planet but will overcome gravity and travel outward. It's a much simplified explanation of what's going on but I hope it helps get a better picture in your mind.

[@nicolasnicolas3889]

@@farrier2708 That doesn't work, we can forget for now that air pressure adds to the force of 'gravity' at the surface, if the escape velocity of gravity is 7 mps then that is absolute...period, if anything it should be less the farther away you are from the gravitation body/center, you're saying that using air in a propulsion system overcomes the escape velocity whereas a rocket with no air pressure/resistance being farther away from the source of gravity has to travel 200 times faster ( I take it that most aircraft with take off flaps leave the ground at around 100 mph, just for easy numbers but not far off), to me that makes absolutely no sense and my point about jumping off the back of the earth still stands....if you fly off the back you are already travelling nearly 3x escape velocity, and amazed that no one ever mentions this? Just fly that way??? The only reason an aircraft won't go into space is that the engines use air for propulsion...noting to do with gravity at all, personally I think all these numbers are complete make believe.....just an open minded, common sense opinion.....thanks for the reply though, I appreciate it.....

[@farrier2708]

@@nicolasnicolas3889 No Nic' ! That is exactly how it works. What you have to learn is the difference between force of gravity and atmospheric pressure. The forces that get an aircraft into the air are created by the speed of the aircraft generating lift. Escape velocity is a speed that overcomes the force of gravity. The two are different solutions to totally different problems and cannot be compared with eachother.

[@nicolasnicolas3889]

@@farrier2708 Gravity is separate to atmos pressure, so why does a space ship, with less gravitational force to deal with, have to fly 200x faster than a plane with more gravity to deal with, makes zero sense? Surely the farther away from the origin of a force and given the inverse square law the space ship would be ok flying slower, that makes sense....seriously, nature is simple, it's functions are simple in respect that they all correspond in common sense ways, hence the inverse square law. Thanks for you reply though!

[@kt420ish]

I love listening to Janna Levin.

[@jonathantsoi2951]

Yes, I sometimes find myself close to a black hole and don't know what to do about it. Now I know what I should do after listening to Dr. Levin. Thanks Big Think!

[@lbdjthethird1240]

Not sure why but this subject makes me cry. Sometimes in terror, sometimes in amazement, sometimes in complete confusion, sometimes just because. Wild shit, man.

[@danielpaproth303]

I thought your explanation of the ISS orbiting around Earth, along with the visuals, was the best I have EVER understood the curvature of space. Thank you for that, and for saying that the engines are off.

[@themanofewords]

Even weirder is the idea that as far as the atoms of the ISS (and the astronauts on it) are concerned, they are moving in a straight line...it's just that spacetime is curved. If that gives you a headache, don't worry, you are not alone!

[@Yetipfote]

she's amazing at explaining our current understandings and limits in a language I understand.

[@tjsogmc]

Ok, but wait a minute. Due to time dilation and such, would it be correct to say that nothing, so far, has actually fallen into a black hole since it would, in theory, take an infinite amount of time to do so from our point of view?

[@StanMills]

That is an amazing thought that I have never heard before! I won’t be able to stop thinking about this. Thanks for your comment.

[@ToySeeker]

Negative Matter 😭 and energy! Thank you Janna Levin I really like these videos! These incredible stories! 🎉❤😊

[@MelindaGreen]

Maybe space itself is being drawn into black holes, and if you enter one, you'll find yourself within an enormous amount of space.

[@michaellee6489]

A lot of scientists are proposing exactly that.

[@JohnAranita]

Thanx, Mrs. Levin.

[@Cringe-at-the-Fringe]

We can't say that there's nothing at the centers of black holes. We can not see into them. It could be infinite density or so dense that it crosses some universal limit. Like an infinite storage container. Is it truly infinite, or is there a limit we're unaware of? Or once a limit is surpassed, will that necessitate a new dimension and so on?

[@seoz774]

This is the paradox. It is interesting to consider how PBS spacetime described a black hole - which was the absence of an event/absence of time - hence the term 'event horizon.' It is like a deleted part of the universe where events don't happen, which raises philosophical questions - can anything really 'exist' under these parameters?

[@johndevoy5792]

thank you for this

[@joseantoniomillabrito2764]

Thanks Janna, your excellent work made me realize my own situation in life. So happy that in my case there is no real gravitational pull forcing me into oblivion.

[@kryts27]

Your wife 😅

[@joseantoniomillabrito2764]

@@kryts27 Not a problem.

[@dumptrump3788]

The problem is that as you fall into a black hole the force of gravity on your feet is higher than your head & you are pulled apart, BUT, since your head is further away so your feet will seem to slow down & hence NOT be pulled away. In effect you are pulled apart & yet not pulled apart.

[@ShadeAKAhayate]

In a small BH, you are ripped apart by tidal forces way before you reach the horizon for time dilation to kick in. In a large BH, you arrive at this 'death area' at such a speed you don't have a time to feel the event, despite your lower part being dilated a bit in comparison to your upper part.

[@PositiveEnergy733]

To everyone reading this, I sincerely pray for that whatever is causing you pain or stress will pass. May your negative thoughts, excessive worries and doubts disappear, replaced by clarity and understanding. May your life be filled with peace, tranquility and love

[@nikczemna_symulakra]

Do not pray for some vaguely defined human being at the end of the world, rather go realistically help a person in need that happens to be right next to you. There are many of them, i can assure you:]

[@marywright373]

Very interesting she explains it so well Thanks

[@sidekick3rida]

I think they recently discovered that information can escape a black hole.

[@matttzzz2]

Bruh. They recently discovered protons as well i heard

[@scottm5425]

From what I gather from other physicists such as Michio Kaku, saying that a black hole does not have a size or surface is actually incorrect since current physics simply does not work in these types of environments, instead all we get is meaningless infinity's. However many seem to have mistaken this error as an answer. So they may very well have dimensions and a shape, but it will take another breakthrough in science to uncover what that could be.

[@EyesOfByes]

Well this little video cost me 51 years. Yes. That is an Interstellar reference.

[@elwitkauesa4148]

And for my next trick!!!!

[@isaacspeaker6376]

This is by far and away the best comment I'll read for years to come.

[@alinsacota7677]

great video!

[@jerrymuns]

It almost seems that a black hole is the physical representation of the “inside/outside” dynamic in which our consciousness travels between wake and sleep cycles. It can also be said that the supermassive black hole is the destination for all matter residing within any given solar system. There’s something more to the inner/outer worlds that I’m not quite grasping in this moment, but it seems like the link between micro/macro, or quantum/general relativity.

[@dmitryshusterman9494]

Sounds like you are ready to start a cult religion

[@skyrien]

Okay, I love the physical concept of black holes... but that journey across the event horizon -- was as beautiful as it was terrifying--the stuff of existential nightmares. Will remember this one for a while...

[@haodev]

Can paths inside the black hole move temporarily away from the center, despite always eventually ending up there? She is saying you could survive inside. Unless that's a poetic way of saying "you would not be instantaneously spaghettified", then there would need to be a path for electrical signals and blood to move around in your body, not just always only closer towards the signularity.

[@thedeemon]

No, the way light cones are warped there, all available paths go "down", it's impossible to stay in place or move up even a millimeter, as it would require moving faster than light or back in time. See Penrose diagrams or Kruskal diagram for more visual representation. So whatever time you got there, it's the time of falling towards singularity.

[@haodev]

@@thedeemon So you agree that it's at the least misleading when physicists say it's possible to survive crossing the event horizon of large black holes?

[@thedeemon]

@@haodev What they say is it's possible to remain alive for some limited time after crossing, and I agree with that.

[@CheCheDaWaff]

Blood could still move from your feet to you head, provided that your head is falling faster than the blood is.

[@bjornragnarsson8692]

@@haodevin a supermassive black holes the tidal forces are minimal until you approach the singularity. That is why they say you may not notice anything unusual (though you would visually) crossing the event horizon and would be able to survive some length of time (assuming you had the necessary sustenance) until the tidal effects start tearing you apart along one curvilinear axis while compressing you perpendicular to that path.

[@RajPatel-di2qw]

Hi Janna, if matters in black hole lost existance then how come black holes with bigger mass has bigger event horizon? What causes its increase in gravitational pull.

[@TheTuubster]

I explain to myself how these massive forces are possible by them being "just" properties of the spacetime elements which in itself are not powerful but simply information, and the effect of these informational properties are experienced in our dimension as these powerful forces. So the "fabric" of spacetime itself, on which these effects like black holes happen, is light weight - like a thin piece of paper that has a drawing of a heavy rock: While the image of the rock is experienced as a heavy object, the color particles on the paper describing the rock as information are lightweight.

[@TheTuubster]

I let the GPT-AI Claude-Instant evaluate my statement. Following is the dialog: "Here is my evaluation of the text: - The core idea being presented is that fundamental physical forces like gravity can emerge from relatively simple informational properties of spacetime itself. This is a philosophical perspective trying to reconcile the immense power of forces with a conceptualization of spacetime as lightweight information. - The analogy of a drawing of a heavy rock on thin paper is used to illustrate how something experienced as powerful (the gravity of a black hole) could arise from something inherently lightweight (the informational properties of spacetime). This is a reasonable analogy to help explain the proposed perspective. - However, no actual scientific or mathematical explanation is given for how specific informational properties of spacetime could give rise precisely to forces like gravity. The text remains at a conceptual/philosophical level without connecting to theories in physics. - Some may argue the idea is speculative and lacks a solid theoretical grounding in our current scientific understanding. Others may see it as a thought experiment to broaden perspectives beyond traditional models. - Overall, while the core idea has philosophical appeal in seeking to reconcile disparate intuitions, the text would benefit from greater specificity and connection to existing physics to strengthen its arguments. As is, it communicates a conceptual perspective but does not conclusively validate or justify the proposed viewpoint. In summary, the text presents an interesting philosophical perspective but would need more scientific substance and theoretical details to move beyond conceptual speculation and engage more rigorously with our current body of physics knowledge."

[@TheTuubster]

Q: What are some existing theories in physics that could potentially support or challenge this perspective? Claude Instant: Here are some existing theories in physics that could potentially relate to or challenge this perspective: - General relativity - The theory that gravity arises from the curvature of spacetime caused by mass/energy. Could support the idea of forces emerging from spacetime properties, but does not view spacetime as lightweight information. - Loop quantum gravity - Attempts to quantize spacetime and views it as woven from tiny quantum loops. Could provide a more information-based conception of spacetime that mirrors the perspective. - Holographic principle - States that a quantum theory of gravity must be holographic, with information density staying constant as more matter is compressed into a region. Lends some support for emergent forces from information capacity of spacetime. - String theory - Postulates tiny vibrating strings as fundamental constituents of reality. Could connect informational properties to vibrational modes that give rise to forces through compactification down to our dimensions. - Causal dynamical triangulation - Models spacetime as a quantum foam of quantized spacetime simplices. Provides a more primitive/informational conception of spacetime structure that could align. - Emergent gravity theories - Propose gravity emerges from entropy/information considerations in a fundamental description without spacetime. Direct challenge if gravity does not genuinely emerge from spacetime. So theories like loop gravity, holography, and string theory offer potential paths of exploration, while emergent gravity challenges the need for an inherently gravitational spacetime. More work would be needed to flesh out specific models.

[@TheTuubster]

Q: Could you provide more information on how string theory connects informational properties to vibrational modes? Claude Instant: Here are some more details on how string theory connects informational properties to vibrational modes that could give rise to forces: - In string theory, the fundamental constituents of reality are tiny vibrating strings, which can be open or closed loops. Their vibrational patterns determine all properties of particles and forces. - These vibrational modes exist in a higher-dimensional spacetime, typically posited to have 10 or 11 dimensions. But our universe only appears to have 3 spatial dimensions due to a process called compactification. - Through compactification, the extra dimensions are curled up into tiny compactified spaces too small to directly observe. But their geometry and topology influence the physics in our familiar 4D spacetime. - Different vibrational harmonics and windings of strings around compactified extra dimensions determine the mass and type of particles that emerge in 4D. For example, a string vibrating at a certain frequency could manifest as an electron. - It is proposed that interactions and forces likewise emerge from the resonant or intersecting vibrational patterns of strings. For example, gravitons may correspond to vibrations of closed strings propagating through the bulk dimensions. - So the informational vibrational modes inherent to strings could connect, via compactification geometry, to properties we experience as the forces between particles in spacetime. This provides a possible theoretical framework linking information to emergent spacetime forces. More work is still needed to flesh out complete quantitative string theory models, but this gives a sense of how it connects fundamental informational properties to forces via higher-dimensional symmetries.

[@bjornragnarsson8692]

@@TheTuubster​​⁠​​⁠I don’t intend to cause any disturbance to your comments, but string theory is kind of dead as a physical hypothesis (technically it shouldn’t even be given the label of a scientific theory). It functions best as a toy model in Anti-deSitter (ADS) space, which is a universe with hyperbolic global geometry, and still has some use helping determine some of the properties a physically and mathematically consistent model of quantum gravity should possess in our universe. It also stays alive for its rich mathematical structure, which is of interest to those conducting research in pure mathematics. Specific areas include enumerative geometry, monstrous moonshine (connecting the monster group with modular functions), superconformal algebra, non-abelian algebraic topology, mirror symmetry and more. The most important lesson string theorists have learned is that the universe does not care how we think it should work. It functions exactly as it should regardless of our subjective attraction towards mathematical beauty.

[@andrewcullen7671]

As you approach a black hole, all straight lines begin to point into the black hole. As you approach the singularity, all lines, in all directions, point into the singularity. BHs don't just warp light, they are literally distorting space, so there's no straight line leading out. RE: black hole cosmology, what if the singularity, defined as a mathematical point where systems of imposed logic break down (like the North Pole on a globe), is both a single point in space and also a pocket universe whose boundary is expanding at the speed of light? Meaning we are in the singularity now. This is difficult to imagine, but that's part of the definition of a singularity in general. You can't cross into a black hole without being spaghettified, but the energy that made up your atoms, when it reaches the singularity, expands into a universe like ours, and this is quantum vacuum energy potential. This would circumvent the paradox of infinite density, as matter never actually collapses.

[@ziff_1]

Black holes are the most fascinating, most interesting objects (places?) in all of existence. I continue to be mesmerized by them.

[@-TheMaskedMan-]

Very well said, I enjoyed this. Sounded as though I was listening to really good story. Well said 🫡

[@scarletevans4474]

If the time slows down so much that I can literally see galaxy evolve, then does it mean that it takes thousands or millions of years (for external observer) for stuff within black hole to reach singularity? If so, is "firewall" kinda real, i.e. if much of stuff captured by black hole requires ultra long time to fall into singularity, then inferior of the black hole should be very hot and dense, right? Won't I just get fried the moment I get inside it?

[@vatandas1542]

Heat also does not escape so ..... Just my 2 cents

[@williamreid8299]

As I understand it - an external observer will see the wristwatch of the person falling in slowing down to a stop (at the event horizon) then the image will gradually fade over (observer) time. The person inside will indeed see the external universe speed up more and more until they are destroyed in the singularity although passing time is unaffected from their point of view so their transition to the singularity is in a finite time from their point of view. Super massive black holes are in fact the coldest thing we know of in the universe. As the presenter said, when the singularity is finally reached - matter and energy appear to stop existing as we know it. Gravity persists however so there is still a remnant although we cannot yet imagine what. What blows my mind about all this is that as you fall into the black hole - time and space swap places. I guess that means Einstein's spacetime becomes timespace! :D

[@scarletevans4474]

@@williamreid8299 Wow, that's so interesting! I need to find out more about this time and space swapping places, I didn't knew it is a thing. Thank You! ♥

[@haodev]

You cant get fried by the heat/radiation of the black hole. Because the radiation is moving towards the center, can cant travel outwards as it would have to do, to meet you as you fall in.

[@michaeltallon9341]

This reminds me of the book Gateway by Frederik Pohl. Terrifying look at a doomed crew falling into a black hole and the people on the outside watching

[@KenSherman]

Still {very} interesting to wonder about the possibilities beyond modern day human physics.

[@jimbosparadise]

I just read her book and it was incredible. Highly recommend. It's a very quick read and it's written in a way that's understandable even to people who usually can't grasp concepts like these. It's also really beautiful which is hard to explain until you read it

[@Buff_Cupcake]

I'm assuming that this is still all theory right? Assumption based on the currently known laws of physics? Because unless we actually go to one and bring back telemetry and data we'll never know exactly what happens in and beyond one.

[@danielshults5243]

We have a lot of direct evidence supporting the existence of black holes, including real images of them from telescopes (more accurately, images of the accretion disk of matter swirling around them. The BH itself emits no light.). The image visible at 1:30 in the video is one such image. We also have observed things like their effect on nearby stars, e.g. stars orbiting around them, and we've also seen the lensing effect they have on light coming from behind them. Unfortunately, by definition, we cannot ever report any findings from INSIDE a black hole, as there is no way to transmit a signal out of one.

[@antred11]

@@danielshults5243 "by definition, we cannot ever report any findings from INSIDE a black hole, as there is no way to transmit a signal out of one" Apparently, all you need is a book shelf in a far away room.

[@miyannaable]

Oh, Man!! Why did I not see this until now? I'm so excited to check out the wisdom of Janna Levin!! AWESOME!! Thank you!!

[@ryanlathotep]

Incredible video and explanation. It makes me wonder if what you pose at the end could be true - what if we do all end up in a black hole, until there is no more matter in the universe? At this point, it might spew all of that matter out, either in the same "universe" or the one on the other side, creating another big bang; creating a brand new universe. And if that's true, who's to say that hasn't happened before?

[@gnomiefirst9201]

Exactly, they're all just theories anyway, why not reincarnation? Infinity is enough time for it to all happen again.

[@randallgvideos]

Eventually all the protons will decay, and the only matter not in black holes are leptons and neutrinos. However as Steven Hawking proved, all the black holes will evaporate by emitting Hawking radiation. Nothing left but photons, leptons and neutrinos, in a universe that has expanded so much that no particles interact anymore. Time effectively ends. Cheers!

[@Sartorri4666]

Matter does not disappear and there is no other side to a black hole any different than the other side of the sun or planet Earth.

[@ryanlathotep]

@@Sartorri4666 then what happens at the singularity? It's where physics as we know it breaks down, at least to my understanding. True, there may not be another "side", but what would happen if a black hole consumed the entire universe? This is just a hypothetical thought experiment - nothing to be taken for literal fact.

[@Sartorri4666]

@@ryanlathotep There is no such thing as a singularity that can be maintained outside of our experiments or computers that I know of. But regardless, a black hole is not a singularity. Consider it a black dwarf star instead of a white dwarf star. You can not pass thru it. To get to the other side you have to go around it the same as you would a planet or star. Worm holes are only theoretical. There is no such thing in reality if you consider every dimension. The imagination can fold two dimensional space back on itself. But I think we can all agree space is not 2 dimensional any more than my arm. You can not go back in time. You can slow time, almost to a standstill, but it can not be stopped! Not even by a black hole. PS there is only the one universe that we can perceive. Not multiple universes, or infinite possibilities. The universe is finite. There is an end. Although that end may involve a cycle and rebirth, it is still just the one universe we have to work with. That's my story and I'm sticking to it. 🤣 I can say without much doubt that this woman is off her rocker and just repeating someone else's brain fart idea/theory.

[@luv2code]

The visualization of the "lensing effect" at 2:40 is disappointing. It's like whoever did that graphic didn't know what lensing is. Especially as graphics used less than 10 seconds later do it in a satisfying way.

[@PitchWheel]

I've always been wondering what if the black holes is so enormous, gigantic, that inside the event horizon there could live entire galaxies, stars, planets and other smaller black holes

[@mattorr2256]

I think with Ultra Massive Black Holes these things may be inevitable. They are so unimaginably huge that anything with them could exist.

[@xSWOOZIEx]

Statistically, it’s a possibility 🎉

[@Wolf462]

No

[@MaxxTrajan]

@@xSWOOZIEx No. no galaxies or stars would exist in that form, if you watched the video, she explained that once you hit the singularity after a finite time, you are essentially torn apart. But there are no "ultra massive black holes" that can swallow entire galaxies lol . thats just being silly.

[@ShadeAKAhayate]

@@MaxxTrajan Mind you, we are living in one. Our observable Universe has a radius that's lower than Shwartzshield's one for the same mass.

[@mollybaylan2730]

I was thinking Satoru Gojo things. Great and enticing video!

[@kastenolsen9577]

A black hole is a place where matter is no longer matter but not yet converted to energy. When enough matter has been consumed into a black hole it reaches a point of "critical mass" and all is converted to energy creating a "big bang". I call a black hole amorphic matter.

[@mister_ttt]

What motivates this assumption?

[@asherplatts6253]

I suspect that the time dilation is so strong that the curvature of spacetime forms a torroidal shape along a time geometry, and connects to the moment of the big bang.

[@MarkusBohunovsky]

So here are 2 questions, that do not quite make sense to me, if looked at from the perspective of General Relativity (ideally leaving Quantum Theory aside, because no one seems to know how the 2 connect anyway): 1) Given that, as Janna explains, time slows down for someone approaching the event horizon, when perceived from the perspective of someone far away from the black hole, and given that at the very point of crossing the event horizon, time should slow down by an infinite amount, would it not therefore look like... a) from the perspective of the outside observer: the one traveling to the event horizon would slow down to zero speed as he approaches, getting slower and slower--NEVER really crossing the event horizon, even while infinite time passes for the outside observer b) from the perspective of the one traveling through the event horizon: When looking back towards the universe outside the black hole, the passage of time in the outside universe would speed up faster and faster, and at the point where the traveler passes the event horizon, INFINITE time would have passed outside, meaning no matter how the universe ends--and in fact even if it NEVER ends (from its own perspective)--the traveler would see the end of the universe before he crosses the event horizon. THEREFORE: While, from the perspective of the traveler, it is certainly possible to cross the event horizon (without even feeling any change in how time passes for him/her), from the perspective of the outside universe NOTHING can EVER enter the black hole, because it can't enter until INFINITE time has passed on the outside. Therefore, the exact opposite of what everyone says ("everything close to the black hole gets absorbed by it") happens: In fact NOTHING can ever enter the black hole until the entire history of the universe has passed on the outside. 2) But this brings up another issue about the very existence and creation of black holes (I am a little less sure about the logic on this second point, but it seems to me that it is consistent) If we think that a regular (rather than a super-massive) black hole gets created when a sufficiently large star collapses, then HOW CAN THE BLACK HOLE EVER COME INTO EXISTENCE within the timeframe of the universe: We would have to think that as the star gets more and more compact and warps space-time more and more around itself, FROM THE PERSPECTIVE OF THE OUTSIDE, time will slow down in the area of the massive star. Therefore that process will APPEAR to happen more and more slowly as seen from the outside. As the star approaches the density where an event horizon starts to form, again time should have slowed down close to INFINITE relative to the outside. Therefore, a black hole can actually never form within the history of the outside universe, as that process will naturally take it into the infinite future, when watched from outside. Yes, I am fully aware that from the perspective of the traveler (in case 1) and from the perspective of the collapsing star (in case 2) there is no issue at all. They can enter the event horizon in finite, even short, time--however we, from the outside could never observe someone entering a black hole, nor can we observe the creation of a new black hole, which means: They should not exist (or they could exist, but could not have been created in our timeline. They would have to be there a priori or simply pop into existence without any transition whatsoever) I asked this question to a supposed expert on a call in radio show many, many years ago and, rather than explaining it, she got very upset and the radio show cut me off. Maybe there is a mistake in my logic, but I do not think it is stupid, and if it is wrong it should be very straightforward to point out the mistake in my thinking for someone who really knows this topic (or maybe they can admit that this just doesn't quite make sense to them either, and we simply don't know..but we DO know that black holes exist, so we just assume they can come into existence within a finite timeframe) Wondering if anyone knows the answer to these questions and has the patience to explain them in layman's terms.

[@olly1oo6]

I can only help with 1(a) - and that is to say that actually, yes. That's exactly how it would appear to an outside observer. The way it was described to me, is that the person falling into a black hole would appear as if they've slowed down to become frozen in time as they approach the event horizon. After that, the image of the person 'frozen in time' approaching the event horizon would then appear (from the outside observer) to fade over time until the outline is so dim that it eventually becomes completely black.

[@Greg-xs5py]

I don’t think you would get stretch out in a black hole. It’s true that your head and feet would get stretched out but so would space and time, so the stretch in your material body would cancel with the stretch in spacetime. You have to think: stretched relative to what? If you’re getting stretched then so are your measuring sticks.

[@ballybunion9]

If the singularity at the center of the hole is infinitely small ... does that mean the singularity has no physical dimensions at all? That's how I would interpret "infinitely small."

[@ziff_1]

That is correct. It has no dimensions.

[@vidropartido]

@@ziff_1 but doesnt the mass of a black hole increases as more and more matter is absorbed? If there is "mass", there must be "something" in the singularity or not? My head is about to explode.. Black holes must be the most fascinating things in the universe.

[@Valerio_the_wandering_sprite]

Consider it more like a moment in time rather than a place in space. At least beyond the horizon.

[@ShadeAKAhayate]

@@vidropartido It still should pack into a dot object. But that's Shwartzshield's black hole, the real ones are more like Kerr's with ringularity instead of singularity (since dots can't spin), internal horizon an a whole bunch of interesting internal mechanics.

[@djb3v]

Best thing i’ve seen in ages

[@fantasycampfilms]

So what are the jets of particles that shoot out of the Black Hole? I think it's called Hawking Radiation...isn't that a by-product of what falls in?

[@iancollings5047]

The jets are from energetic accretion disc's, while hawkin radiation is due to the annihilation of one of two virtual particals that are created continously as part of quantum fluctuations.

[@vladskiobi]

​​@@iancollings5047 Actually, the opposite is true. Hawking Radiation doesn't come from the annihilation of two virtual particles, that's what happens everywhere else. But next to a black hole, one of the pair of particles falls in, and the other escapes, becoming a real particle. That mass and energy has to come from somwhere, though, so the new particle steals energy and mass from the black hole, thus Hawking Radiation.

[@iancollings5047]

@vladimirkool-aid2450 that is what I said. Due to the annihilation of one of two virtual particals.

[@vladskiobi]

@@iancollings5047 One particle can't annihilate. Annihilation requires two particles. Particles of equal mass but opposite charges. An Electron and a Positron, for example. In this case, though, one particle escapes and the other falls into the black hole. No annihilation occurs.

[@iancollings5047]

@@vladskiobi acknowledged I meant one gets effectively annihalated, as far as the rest of the universe is concerned, when it falls past the event horizon and the other does not and escapes as hawking radiation.

[@suncat9]

Janna, as a physicist, you must know that empty space does not exist. Space always contains fields as well as virtual particles that blink in and out of existence. Also, as Richard Feynman said, infinities such as infinite density or infinite spacetime curvature don't exist in the physical universe. Infinities in the mathematics describing the physical universe signify where our UNDERSTANDING of the physical universe breaks down.

[@erickwalker11]

I'm an airline pilot but I think I should have been some kind of space scientist or whatever they're called because I find the whole idea of anything out in space especially black holes absolutely beautiful and I find myself studying the shit out of this stuff for what reason I have no idea.

[@Sartorri4666]

We all need to know why.

[@malloid]

This made me laugh. The reason is simple: curiosity and a thirst for learning and knowledge. Some people have it - and lap up anything astrophysics or astronomy-related - and some people watch game shows on TV every night... ⚫⭐🔭😁

[@Sartorri4666]

@@malloid I do both. 👍

[@ShadeAKAhayate]

PBS Space Time channel has a couple of playlists on the topic, explaining it exhaustively.

[@pikiwiki]

probably healthier@@Sartorri4666

[@zmirburger]

Janna Levin is great!

[@ourmuse]

Black hole is saying that "what you gonna do about me 😜" 💀💀💀

[@lxwin2]

7:35 Why do black holes violate the laws of conservation of mass and energy? Black holes have mass and spin (rotational energy). Mass and energy can be increased when matter or particles falls inside. Mass and energy can be decreased, e.g. through hawking radiation. Information may be lost, but mass and energy is "lost" or "deleted"

[@will2see]

Now think of all the educational YT videos that present themselves as the 100% correct way to talk about black holes. "What is a black hole? We will explain it to you. Just subscribe and like this video!" Every single one of them starts with the sentence: "A black hole is an immensely dense and compact object." (or something in that sense). The irony is that a black hole is neither an object nor is dense (since it's not an object and density is only defined for physical objects). In fact, a black hole is a region of space-time with some extreme properties. But nobody is saying that! I am mad when I hear some arrogant intellectuals start their video presentation with two false statements right in the first sentence of their video! We all say that a black hole has such and such mass. But (basically) nobody realizes that the word mass is just a proxy for the curvature of space-time (that a massive physical body with the same mass would exert on the space-time around it). Black hole is not made of mass! Black hole is the region of the curved space-time itself, where the escape velocity is larger than the speed of light. It's madding how so many YT "astrophysicists" and "educators" and arrogant "explainers" get it wrong right from the beginning. And these people fit themselves into the role of explainers for the rest of us. 🤦‍♂🤦‍♀🤢🤮

[@Sartorri4666]

Wow dude. No more heroic doses for you. You're cut off. Everything you just said is complete nonsense. 😂😂😂

[@jasoncruz19800]

I'm a graduate student in astronomy...black holes are astronomical objects. I'm sorry but that video presenter was exaggerating for the sake of making interesting youtube content

[@Sartorri4666]

@@jasoncruz19800 She's a teacher though right? How can we allow this to be taught when it's nonsense? 🤦

[@jasoncruz19800]

@@Sartorri4666 not everything she says is nonsense, just her exaggeration talk concerning black holes being "nothing" and almost mystical like esteem for it, when it's well defined

[@Sartorri4666]

@@jasoncruz19800 I find when part of the theory is false the whole theory is wacky. I don't think she really understands what she's talking about, but rather rest and memorized other people's work.

[@daryleldridge7769]

She has an awsome style of presentation...

[@arnaud_ober]

I'm always impressed how curious I am about black holes and time in general. At some point, you said if I understood correctly, that once our atoms are in the singularity, you cease to exist, that's it's the end. Does that mean that a singularity is the end of everything? That there is nothing else? And as there are infinite singularity in space (each black hole has one if I understood everything), what could happen if two singularity merge/enter in collision together? Or is that absolutely impossible?

[@Tomasegilsson]

Black holes can in fact merge and their merger creates gravitational waves that ring out across the entire universe. These waves further were detected by the LIGO observatories in 2015.

[@michaelzimmermann3388]

also, there is something that is not lost at the singularity: energy (which translates to mass E=mc2 but never mind). this energy will be released back to the universe via hawking radiation. so the ultimate fate of a black hole is death too. after the last black hole will have evaporated, nothing can ever change in this universe, the end of everything.

[@Brago.Oficial]

​@@michaelzimmermann3388Just a speculation.

[@Brago.Oficial]

Yes black holes can merge and the biggest black hole just swallows the smaller one and become bigger.

[@vidropartido]

black holes do not violate the law of conservation of energy/mass. So no..The singularity is not the end of everything.

[@seraphik]

janna f'ing levin is one of my favorite science communicators/scientists ever.

[@rayflyhigh]

This video felt similar to being in church talking about God, death, or Heaven. A lot of theory about a thing no one has been to and back to tell us for certain. *shrug* this was entertaining though. I hope one day we’ll be able to know on this side of it

[@Madjicle]

Just beautiful... ❤

[@RetroChiZ]

Has anyone ever explained a black hole without saying "not even light"?

[@thelaurels13]

You shouldn’t have skipped school so much. 🤡

[@abstract5249]

Nope. Not even light😉

[@hAze_the_shrimp]

7:04 had a nightmare about this, falling into a black hole, every atom in my body breaks apart and ceases to exist... terrifying.

[@lecavalier32]

Dr. Levin is a champ.

[@WritewheelUK]

Thanks for the video. If, as you say, from an outside observer, the 'clock' of someone orbiting very close to the black hole, right on the border, would be shown as stopped, does this not mean they will have a sort of immortality? At least if they had found some way to avoid the radiation on their way in, and until the black hole evaporates. Also, do you also get headaches thinking about black holes?

[@sir_fapalot]

You would be frozen in time aka dead

[@thedeemon]

You're hardly immortal if by your own clock you have very limited time until getting to singularity. The fact that outside observer will forever "see" your image near the horizon is more of an optical effect, a matter of relativity of simultaneity - later and later moments of their timeline are "simultaneous" to different moments of you approaching the horizon but never touching it, and it's not how it looks for yourself.

[@konga8165]

I bet we have this all wrong and we’re going to look back one day and laugh.

[@odysodys1098]

Fascinating, and great graphics! The more stuff you stuff into one place the faster it becomes nothing. Lucky for us stuff is only something we use and not what we are.

[@nomadautodidact]

I just can't understand how if a black hole is nothing, then why are they different sizes? Why do 2 black holes that combine become the sum of the two parts if they're just nothing?

[@billcook7483]

Janna Levin is so smart , in my opinion she makes our home grown Brian Cox look like a dimwit in comparison . She is a real , worthy professor of physics .