***** I'm getting tired of that comparison. People saying that often apply it to all of science without knowing all the things their examples have in common, most of which aren't present in some current theories. We may have disproven classical mechanics but it still makes great predictions at most common scales. And it's not going to stop being true just because "scientists used to say uranium could cure cancer so they may be wrong about this too". You have to be critical about everything, but that doesn't mean you should assume that most things we know are wrong.
@@hxhdfjifzirstc894 every single person on earth knows infinitely more things that arent true than they know things that are. and theoretical physicists especially never claim to know the truth without it being mathematically and undeniably proven in the first place
OMG I was thinking the same thing lol but I do enjoy these videos, it's interesting to see how a physicist try to simplify an explanation of what's happening in the quantum realm.
I usually have to watch these videos 4-5 times. I'll start thinking about something you said at the start, then the videos over and I've been thinking about the first minute the whole time.
We wont ever have all the answers, since like the other comment said, it will only lead to more questions. However, if you have the drive to search for the answers to the never ending questions, at least you can help provide answers to the questions of those who come to the same state of mind. If you cannot stop, then why bother trying to find an ending, why not embrace the infinity of the pursuit of knowledge. Those with mind's that realize we never trully know anything, are those who can change the world and our understanding of our place within it and perhaps the place we can have outside of it.
Study (Astro)physics at a university, then you will learn *some* of the *possible* answers. Videos can only scratch the surface, and most of them are simply nonsense. Specifically those in which someone claims to have found “the theory of everything”. But laypeople rarely notice that, of course. (Otherwise they were students or scientists in the field.) Even in this otherwise good video (I could not find other obvious mistakes yet), the pop-sci statement “[a black hole] has a point of infinite density, the singularity” (3:01) is complete nonsense: Instead, a black hole is a region of spacetime surrounding a singularity. And that singularity is a mathematical result (the line element/Kretschmann scalar approaches infinity there); it is neither a physical object, nor a place, or even an event (it is not part of the spacetime manifold, so NOT part of the black hole; notice the *precise*, *mathematical* wording indicative of a *scientific* statement). (This is corrected in another video on this channel by Gabe Perez-Giz, who is actually a physicist researching general relativity.) It is actually a result of our inability to describe our universe completely (using general relativity), and probably does not even exist. (As theories of quantum gravity would predict.) Keep in mind that we do not know how things really are; we are just making educated guesses so that we can describe and predict mathematically what we observe. When we say “it is” in the (popularized version of the) natural sciences, it almost always only means “what we think how it could work”.
6:03 "The compactified gridlines there now represent the stretched spacetime near the event horizon." This is the part that (I think) needs loads more explanation.
Ive been watching your videos for years. out of all the concepts you have brilliantly expounded upon, the penrose diagram for me, is the most difficult to wrap my head around. Ive watched this video at least a dozen times. anything black hole 🕳 related is probably the most abstraction in thought you can assume, yet so beautifully simple in its existence.
Nothing embarrassing about that. It took alot of math and exploration for Spacetime to get this info. That's what I love about these shows, they're challenging
Don't worry, the best theorists in the world run into serious trouble when we approach the event horizon. Something very weird has to happen there, and no-one is quite sure what flavor of weird it actually is.
Usually, I can come away from these videos feeling like I understood at least a very small portion of the subject matter. This one, however, just made me feel like my brain is dripping out of my ear.
Grin Reaper Of Trolls It would counteract it. Since the warp drive works by generating negative energy density, you would destroy the black hole by distorting gravity itself.
Moving faster than light (relative to a stationary reference) is certainly possible mathematically. And that means it is almost certainly possible in reality. The problem is the transition from sub-light to super-luminal. In order to attain such a velocity, you have to transition the actual speed of light you can't just instantly accelerate beyond it in an instant. And that particular velocity causes a division by zero in the equation that describes the energy/mass involved. So practically, it's not possible as you can't get past the barrier of c.
inside the event horizon, space expands into inself faster than outside, and all expansion is directed into the ingularity. So, if you are traversing that space, your only direction would be to the singularity
@@fredlockard4509 THE ULTIMATE (AND CLEAR) MATHEMATICAL UNIFICATION (AND PROOF) REGARDING PHYSICS/PHYSICAL EXPERIENCE IS NOW DEMONSTRATED, AS E=MC2 IS F=MA: TIME DILATION ultimately proves (ON BALANCE) that E=mc2 IS F=ma, as ELECTROMAGNETISM/energy is gravity. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. (Importantly, balance and completeness go hand in hand.) The stars AND PLANETS are POINTS in the night sky. NOW, A PHOTON may be placed at the center of WHAT IS THE SUN (as A POINT, of course); AS the reduction of SPACE is offset by (or BALANCED with) the speed of light (c); AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Indeed, ultimately and truly, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS E=MC2 IS F=MA; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black. GREAT. Accordingly, INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/PHYSICAL EXPERIENCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. It ALL CLEARLY makes perfect sense. Gravity IS ELECTROMAGNETISM/energy. E=mc2 IS F=ma. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=MC2 IS F=MA. GREAT !!! Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS E=mc2 is F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Consider THE MAN who is standing on what is THE EARTH/GROUND. Touch AND feeling BLEND, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. The stars AND PLANETS are POINTS in the night sky. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Accordingly, the rotation of WHAT IS THE MOON matches it's revolution. Great. MOREOVER, a given PLANET (including what is THE EARTH) then sweeps out equal areas in equal times consistent WITH/AS F=ma, E=mc2, AND what is perpetual motion; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. Stellar clustering ALSO proves ON BALANCE that E=mc2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity. Objects (including WHAT IS the falling MAN) fall at the SAME RATE (neglecting air resistance, of course), as E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/energy is gravity. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 IS F=ma. THE DOME of a PERSON'S EYE is ALSO VISIBLE. (Notice the flat AND black space of what is THE EYE.) The stars AND PLANETS are POINTS in the night sky. The sky is blue, AND the Earth is blue. THE EARTH/ground AND THE SUN are E=mc2 AND F=ma IN BALANCE, AS ELECTROMAGNETISM/ENERGY IS UNIVERSALLY PROVEN TO BE GRAVITY in what is a mathematically unified fashion. E=mc2 IS F=ma. The middle distance in/of/AS SPACE AND the full distance in/of/AS SPACE are NECESSARILY linked AND balanced. MAGNIFICENT !!!!!!!!!! INSTANTANEITY IS thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. It is ALL CLEARLY proven. Again, the stars AND PLANETS are POINTS in the night sky. GREAT. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. It is all CLEARLY proven !!!!!!!! TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. GREAT !!!!!!!! BALANCE and completeness go hand in hand. By Frank DiMeglio
This lesson is beyond my current understanding. But I got enough of it to begin a wider understanding. PBS Space Time is brilliant and so so valuable - thanks for bringing this to us! PS I'm a PBS station member!
Dare I say it, not just many, but EVERY topic. Except possibly things like pure mathematics, for which 'evidence' does not apply, unless you count mathematical proofs as evidence.
Say there's a thousand bots on Yelp and really any platform designed to hype things. Say you can pay x amount to have a thousand Joe's and janes to drop positive/negative reviews. Say I already know it's true even without evidence. Say I know alot of independent manufacturers put crypto miners on their computers. Say I have no evidence but I already know it's true. Say that even the numerical evidence supports one thing whilst belief is true. Lol No.
I like to say thank you, most of this stuff is out of my league, buy you have helped me understand the basics. the universe is beautiful, thank you again.
Dan Howell ..No not all black holes would ripp you apart ..supermassive black holes , has somewhat less densities -like one in the centre of our galaxy..supermassive black holes has less tidal effects..supermassive I mean billion times the mass of sun. you will fall in just as the same as if you were to fall on earth
Is that really your head in that emoji icon? If so, it appears your head has already fallen over the event horizon! A hairy turd ball that eternal black hole stuck a face on to try and make it easier to digest!
Dude could you ask your dad what the singularity is inside a black hole? And then come back to earth to tell us what it is, it could help us a lot. We won't nail you to a cross this time mate.
Yeah, man. The "escape velocity" is the speed REQUIRED to leave the gravity of an object, and it's entirely possible for that to go beyond the speed of light, making it impossible to leave a black hole. Jeez. (but maybe OP was just being sarcastic)
"Why do you think ALL IMAGES of planets and space are cartoons??" It's a troll Runos. It takes a single google search to find a real life image of planets and space. Actually, does anyone have that link to the fucking INTERNATIONAL SPACE STATION livestream? It's really cool, seeing
1) If two black holes are close to each other will their event horizons deforms making them not spherical shape? 2) If answer to 1) is true, Is it possible to escape event horizon when two black holes collide ?
But if gravity is force and works similarly as electromagnetic force shouldn't force pooling you towards black hole between those two be equal zero. Moreover it be equal to zero on line perpendicular to line which contains those two black holes on it. Assuming that all mass in black hole is in its center, just before the collision will be line which goes through center of black hole to infinity on which the potential energy of gravity is zero.
No, once you're in the event horizon, you've been lost. However, the event horizons can bend, and you might find yourself some extra time by narrowly dodging the horizon if it bends in your favor. Or it could catch you by surprise not too long after you've barely escaped it.
I think you are correct, at a point exactly between the two black holes, gravity should be zero, and therefore that point should be outside the event horizon of both black holes. But how do you get there? When traveling towards it, you need to endure the gravity of *both* black holes, not sure whether the allows you to stay out of the event horizon of both.
Hey I've got a genius idea for the rescue mission! What about if the ship hangs out outside of the event horizon and drops a rope (always have a rope) down to the monkey PAST the event horizon, in that case we could easily rescue him and, in the meanwhile, break (correct I would say) the laws of physics. Also, captain is played by Chuck Norris..
Philip Glenn de Catalina That is until I throw the other end of the rope into the neighboring bigger black hole... Bet you didn't think about that huh? xD
TimmacTR, I would think that if the combined center of mass of the ship and monkey was outside the horizon then it would be possible. But if you had MacGyver, he could accomplish it with string, paper clips, and a ballpoint pen.
KsJayhawker94 Still interesting to think about it. The monkey would have a lot of stories to tell...though, the crew in the ship would be much older, so maybe it's the opposite.. xDD
Basically, you'd have to put so much energy into pulling the rope, that it would have to pull the monkey, _faster_ than the speed of light, outwards. So, yeah, it won't work.
Coolest thread I've ever seen on UA-cam is on this Video - Ahhhhh there are cool normal people - they're in the Intelligent Tribe - on the Physics Channel! ⚛⚛⚛⚛⚛⚛⚛⚛
You’ve made a number of videos that address the standard black hole model. How about analyzing other models? I’m particularly interested in Abhas Mitra’s magnetospheric eternally collapsing object (MECO) model.
Thank you for making these videos! Among the many channels I often watch, this is the only one that consistently challenges me intellectually. There are some of them that I don't think I could understand even if I watched them like three times. :-D
“What actually transpires beneath the veil of an event horizon? Decent people shouldn’t think too much about that.” - Academician Prokhor Zakharov, “For I Have Tasted The Fruit”
The most interesting effect isnt what happens at the event horizon; but what we believe happens at the singularity.... Please touch on that subject in a future upload PBS.
"What actually transpires beneath the veil of an event horizon? Decent people really shouldn't think too much about that (about that)." -- Academician Prokhor Zakharov, "For I Have Tasted the Fruit."
Thanks for the great videos. Here's a question about black holes that our group has had for more than ten years: If from the perspective of the outside observer, the person traveling to the black hole or anything else never crosses the event horizon because time becomes nearly infinitely slow from our perspective, then we observers should never observe black holes growing in mass. For instance, instead of observing super massive black holes, it seems that we should instead observe these black holes only as small black holes (as when they first came into existence) with enormous amounts of matter frozen just outside the event horizon. Even if a BH has collided with a neutron star, not enough time has passed (from our perspective) for the neutron star to have passed the event horizon. What are we missing?
Yes, I have the same question. Does it mean that we can see all that staff trying to pass behind the event horizon but never be able to pass? I saw something similar at DrPhysicsA but event more confusing he demonstrates the oposite.
@@nicu_danciu I never found an answer to my specific question. I probably could have worded it better. However, one thing that I did learn is that even before objects cross the event horizon, their radiated light would be stretched so much that they would no longer be seen as visible light.
I agree with the other replies that a singularity technically doesn't make sense and *probably* isn't actually a real thing BUT I will remind you all that you're not in charge and just because our mechanical brains don't like the sound of something doesn't mean it's not real. To quote Niels Bohr: Don't tell God what to do.
What Gareth said. The inward direction acts like the future direction. So, once inside the horizon, avoiding the singularity is like avoiding next Tuesday.
Would it be possible to temporarily dip below the event horizon if two large black holes fly by each other close enough to overlap eachother's event horizon so one may ride the lagrange point between them? There's probably something missing like black holes that close would inevitably collide.
Basically everything has an escape speed to leave its gravity earth does. You can’t escape a black hole because the escape speed meets or exceeds the speed of light.
Thank you for not dumbing this down or pandering to the lowest common denominator like most youtubers do ("not even light can escape guyzz..."). It's about time someone gave the viewers a small taste of the complexities of real astrophysics. And to people who crack jokes about not getting it watch it 3 times and you will.
There's always the asshole who think's they're smarter than everyone else. Intelligence isn't a measure of how much data you have in your brain, it's how fast or well you can process it and apply it. Being condescending and saying "It's cute that you think they're not dumbing this down" isn't a show of your superior intelligence, it is a show of your ego and insecurities regarding the democratization of information, that challenges your perception of intelligence.
I have a very important question : How does a photon "sees" the world? As it travels through the speed of light and as time stops at the speed of light, how can it moves through space without time? Does it access all time dimensions? Could it be in a dimension where the entire universe since the big bang is?
I just looked at the channel bar and said out loud “Dude, how am I not subscribed???” I’ve been on a bit of a PBS Space Time binge lately, so I honestly thought I had already done it. 😂 Remedied 👍🏻
So, say I constructed a ship that could hover over the event horizon, I could theoretically experience less time than the rest of the universe? If I waited 100 years there, how many year outside of my position would go by? Is the bending your light cone to time travel?
If your ship could hover just outside there, it would need a great deal of acceleration to stay there against the infall of spacetime ... so yes, because acceleration slows your time rate relative to inertial reference frames, and a lot of acceleration slows it a great deal. --Dave, just need to see it the right way to find the simple answer
9:55 I don't get it. If you and the monkey are travelling faster than light, how would you see anything? Wouldn't everything ahead be an infinitesimal point and likely blue shifted beyond obscurity?
ExaltedDuck You have to also take into account the relative speed of everything around you. If everything around you, including light, happens to be travelling at the same relative speed, you would see more. Unless of course everything around you is travelling faster than the speed of light all in the same direction, straight towards the singularity, well then you are right, you wouldn't see much of anything.
ExaltedDuck relative speed bruh. the only reason why when you are at some planet at the andromeda galaxy and you spy at someone from the milky way galaxy and they appear to be moving faster than the speed of light.
ExaltedDuck But what if there is a light source inside a black hole, past the event horizon in front of, or beside you. Is it possible, if the force is ever increasing leading to the singularity, that you would not be able to see the light source because of the increasing force bending the rays directly toward the singularity instead of into your retinas?
ExaltedDuck I mean we know the image on the event horizon appears to freeze, then slowly disappear, but past the event horizon, where the force is pulling light inward greater than the speed of light, wouldn't that make it impossible to see these light sources in front of or beside you?
A few comments cued by the video elapsed times: 3:10 It’s not a “point”. First of all, it's not a part of existence, or as John Wheeler aptly put it: "There is no 'there' there". In yet another words, the singularity in the Schwarzschild black hole is not a _place_ but something like _tomorrow_, i.e., everywhere in your future. 6:29 Not true - the lines of constant space and time do not switch. This is a common misunderstanding and I'm surprised this error has made it here: (a) that "switch" is purely man-made, it's simply a property of a certain coordinate system, i.e. our human bookkeeping system. It's not anything real and is simply a consequence of lazy re-use of coordinate _labels_ while solving the Einstein equation for the black hole. In good textbooks (like Hawking & Ellis for example) the relevant letters/labels are kept "straight" precisely to avoid this confusion. (b) Moreover, in the video this is mentioned while showing the Penrose diagram which is a type of coordinate system where this switch does _not_ occur anyway. 9:50 It should have been simply stated that the effect of the monkey appearing frozen at the horizon is purely an optical effect, not unlike a fatamorgana, due to the light signals being delayed. 10:35 Work on the pronunciation of “Schwarzschild” some more :-) Hint: "w" is pronounced as an "f", "z" as the "zz" in "pizza", and "Schild" means "shield" and is pronounced likewise (but that final "d" is like "t"). His name means "black shield" - really! 11:25 Big bonus points for finally mentioning the rotating (Kerr) black hole. Since FAPP all the black holes in the universe (if they exist as predicted) are rotating, it is indeed weird that virtually all pop-sci presentations ignore it and focus exclusively on the nonrotating (Schwarzschild) case which is a bit like a pencil standing on its tip: possible but unlikely to have the angular momentum exactly zero! The reason rotating black holes are interesting is that according to the classical (non-quantum) theory _they are not fatal_: the singularity is actually quite _hard_ to hit, any object free-falling into it would have to follow an _exactly equatorial_ trajectory in order to hit it, in fact the singularity itself, which is in the shape of a ring, is strongly gravitationally _repulsive_. But given enough initial push one could fall _through_ that ring into another universe. If the mass of the black hole is large enough (about 400 million solar masses, say) the falling object would not feel _anything_ while falling through as the tidal forces would be about equal to what you are experiencing right now as you’re reading these words. As I said, for some odd reason pop-sci books never discuss Kerr black holes despite all this intriguing weirdness, I could go on like this for a while but the margin is too small to contain it :-)
First off: Awesome constructive comment for a youtube video! About the 3:10 part though (note: this stuff is just all hobby and interest for me so I don't intend to claim I know better), for me it's easier to actually imagine it as a infinitely small point with infinite density etc. instead of... a everywhere :) Isn't that also what is usually told to people? Do you have any sources so I can read more about it though? I'm interested in finding out what you exactly mean by that!
What I meant was that two (say) _pointlike_ objects falling along the same path down but at different times will both end up crushed but at different locations. The spatial region inside the horizon is, strangely, not a 3D ball but a homogeneous 3D space of infinite extent, two dimensions of which form spheres, so the whole region inside is, at every instant of time, like an infinite "row" of spheres, with entire row having smaller and smaller radii as the time passes. Because of that the object cannot "visit" this region at will because with every instant of passing time the object finds itself in one of those spheres of smaller and smaller radius, until it's crushed. So different objects get crushed in different places.
ballom29 I know , it's like mixing two very very very viscous liquids together . The 2 black hole's event horizons start to bulge out slowly towards each other , after getting closer in terms the space outside of the horizon the space time stretches and stores the energy in the form of stress and just after the signal from the singularity merger reaches the gooey horizon the boom the energy is released as humongous gravitational wave . In the core however I think the singularities somehow fight for survival until one of them have to get soaked up out of existence. 😓
I wonder too. If they are both spinning in the same direction, and event horizons touch at the equator where the matter just outside of the event horizons has opposing trajectories and past which none of the matter can escape, wouldn't the program crash due to a math error, or result in such a big energy release that the universe has actually already been destroyed and this is in fact the afterlife? My thought is that what happens inside of an event horizon must follow drastically different circumstances relative to what happens outside of an event horizon, or rather follow a logical path that makes the circumstances outside irrelevant to the circumstances inside, because while they're merging, the surfaces would still be theoretically moving in opposing directions on every part of the surface that has not merged. Inside, it must be a different story which must be conceived in different terms. Imma' retract somewhat though. Maybe it would be more likely that they would spaghettify each other prior rather than 2 spinning blobs grinding against each other? Or the more massive one spaghettifying the smaller one and warping only slightly itself? This would probably look like a swirl to an outside observer, but would probably be less skewed (If at all) from the perspective of the local space that the matter inhabits. I'm pretty much wildly pontificating at this point, and Imma' stop.
It would not. Although photons can in principle orbit the black hole at 1.5x the event horizon radius, those orbits aren't stable, so very little light is actually trapped there. That said, real astrophysical black holes are almost never isolated. There's a lot of stuff that falls in -- even the intergalactic gas would be superheated and glow very brightly (even in x-rays) as it falls in, and that radiation would be lethal to you as you approached. Funny thing about black holes -- they're the darkest places in the universe, but the region immediately around them is also among the brightest in the universe.
i have 2 questions about escaping a black hole. first if you had an alcubierre drive could you pass through the hirizon and back out or would the warping of space time interfer with you drive. second if you had a wormhole and you took one end into the black hole could you use it the get out of it and see yourslef frozen at the horizon.
wow the second one is pretty good , that would be like cutting a hole through another hole in the very fabric of space-time , it is mind boggling really
this might sound ignorant, but the explanation of a black hole makes me think of a common drain that one might have in a sink or tub. as the water or liquid and any substance that happens to be floating or below the liquid gets closer to the drain, not much happens other than the flow is pulled to the spiral created by the drain. once the liquid and substance in said liquid enter into the spiral, they do become entangled and twisted as they enter farther and farther in until there is a single stream if you will. this does make you think and the similarities between how liquid acts as it enters the spiral of a common drain and the workings of a black hole could indeed make it easier to understand.
So if you crossed the event horizon, would you be blinded by light that was trying to get back out? And because spacetime is warped down to a point, are there an infinite amount of successive event horizons between the initial one and the singularity?
after every video I feel more educated and more confused at the same time...
Karlsson there's a quote about for every question answered they will lead to simply more questions
That's what knowledge does to you.
Welcome to science, hope you enjoy the ride!
Science!
***** I'm getting tired of that comparison. People saying that often apply it to all of science without knowing all the things their examples have in common, most of which aren't present in some current theories.
We may have disproven classical mechanics but it still makes great predictions at most common scales. And it's not going to stop being true just because "scientists used to say uranium could cure cancer so they may be wrong about this too".
You have to be critical about everything, but that doesn't mean you should assume that most things we know are wrong.
I've always been impressed at myself believing that I understand even the foundations of these concepts.
I wind up watching them more than once and even wrote a summary of one once to see if I could explain it in my own words. This is great stuff.
If you watch this channel, you probably know dozens of things that aren't even a little bit true.
Quantum thinking.
@@hxhdfjifzirstc894 every single person on earth knows infinitely more things that arent true than they know things that are. and theoretical physicists especially never claim to know the truth without it being mathematically and undeniably proven in the first place
@@JubioHDX we can’t even prove more than that we exist and that there is something structuring our perceptions
You should make a shirt that says
“What happens below the event horizon *stays* below the event horizon”
Lol
underrated comment!
Vegas is black hole for money. Money is kind of energy appearing from nowhere in Federal Reserve System.
Why don't _you_ make it?
If you make it, comment, I'll buy it.
I never feel knowledgable enough to comment intelligently but thank you for these great videos.
Comment anyways. It might lead to me understanding all of this.
Bobby Harper Agreed my friend
The most intelligent comment is a question.
_BABOOOOM_ the sound of minds exploding
OMG I was thinking the same thing lol but I do enjoy these videos, it's interesting to see how a physicist try to simplify an explanation of what's happening in the quantum realm.
@hi so, what does that make your comment then? /jks that was really good
I usually have to watch these videos 4-5 times. I'll start thinking about something you said at the start, then the videos over and I've been thinking about the first minute the whole time.
😂 sounds like me
I can’t move on until i understand something fully
7:06 “now that we’ve nailed the penrose diagram...” umm I’m not sure I’ve nailed anything other than the fact that I’m severely confused.
I nailed ur mom 😂
@@Amy-si8gq I watched you nail his mom lol *fist bump*
Discord
These diagrams are all used for warp fields
Gamma rays
I hope spacetime episodes continue to be produced far beyond the time that it takes for us to see something cross the event horizon 🙏
I have a problem... I'm having existential crisis and i can't stop watching these videos about theory of everything. I don't need sleep i need answers
Every answer eventually leads to another question.
@@briank1263 yeah that's true. But won't it be good if we all got same answers.... Then that means the answers have some truth to it
We wont ever have all the answers, since like the other comment said, it will only lead to more questions. However, if you have the drive to search for the answers to the never ending questions, at least you can help provide answers to the questions of those who come to the same state of mind. If you cannot stop, then why bother trying to find an ending, why not embrace the infinity of the pursuit of knowledge. Those with mind's that realize we never trully know anything, are those who can change the world and our understanding of our place within it and perhaps the place we can have outside of it.
I seriously don't understand how anyone couldn't be fascinated with how reality works, but most people literally just don't care
Study (Astro)physics at a university, then you will learn *some* of the *possible* answers. Videos can only scratch the surface, and most of them are simply nonsense. Specifically those in which someone claims to have found “the theory of everything”. But laypeople rarely notice that, of course. (Otherwise they were students or scientists in the field.)
Even in this otherwise good video (I could not find other obvious mistakes yet), the pop-sci statement “[a black hole] has a point of infinite density, the singularity” (3:01) is complete nonsense:
Instead, a black hole is a region of spacetime surrounding a singularity. And that singularity is a mathematical result (the line element/Kretschmann scalar approaches infinity there); it is neither a physical object, nor a place, or even an event (it is not part of the spacetime manifold, so NOT part of the black hole; notice the *precise*, *mathematical* wording indicative of a *scientific* statement). (This is corrected in another video on this channel by Gabe Perez-Giz, who is actually a physicist researching general relativity.) It is actually a result of our inability to describe our universe completely (using general relativity), and probably does not even exist. (As theories of quantum gravity would predict.)
Keep in mind that we do not know how things really are; we are just making educated guesses so that we can describe and predict mathematically what we observe. When we say “it is” in the (popularized version of the) natural sciences, it almost always only means “what we think how it could work”.
Thrilled as to how far we've come as a species, in pursuit of infinity. Great production
I don't understand anything after the 3 minute mark on every video but it blows my mind. I'm always waiting for new videos.
6:03 "The compactified gridlines there now represent the stretched spacetime near the event horizon." This is the part that (I think) needs loads more explanation.
Be smarter.
@@TheNamesFarquaad clearly, you must know everything there is to know in order to make a statement like that
@@SLAPFACE247 Yes.
@@TheNamesFarquaad shows how smart you are buddy
@@TheNamesFarquaad never discourage someone from being inquisitive. Maybe that’s something you’ll learn one day
Ive been watching your videos for years. out of all the concepts you have brilliantly expounded upon, the penrose diagram for me, is the most difficult to wrap my head around. Ive watched this video at least a dozen times. anything black hole 🕳 related is probably the most abstraction in thought you can assume, yet so beautifully simple in its existence.
This, oh yes so much. So many things properly outlined here. I knew all this stuff, but this framework is so much more visually intuitive. Glorious.
Not afraid to admit: barely understood a word of this. It was like trying to explain the internal combustion engine to a chimpanzee.
Let me ELI5 for you;
Space is fucking complex, bro
Nothing embarrassing about that. It took alot of math and exploration for Spacetime to get this info. That's what I love about these shows, they're challenging
My take away is that we can take everything we intuit about space and time we would normally perceive and just shove it up our assholes.
more like, explaining it to a chimpanzee that's falling into a black hole
Don't worry, the best theorists in the world run into serious trouble when we approach the event horizon. Something very weird has to happen there, and no-one is quite sure what flavor of weird it actually is.
Best explanation of Penrose diagrams I have come across on YT. Inside the black hole time becomes space-like and space becomes time-like.
Usually, I can come away from these videos feeling like I understood at least a very small portion of the subject matter. This one, however, just made me feel like my brain is dripping out of my ear.
This video made me feel every single emotion in the span of 20 minutes
I came here seeking answers, and left only having more questions.
science.TXT
But were the initial questions answered
Ad I left feeling stupid
thats the beauty of science
A common paradox where black holes are concerned.
What would happen if you had a warp drive? How would the warp bubble affect the event horizon?
Grin Reaper Of Trolls It would counteract it. Since the warp drive works by generating negative energy density, you would destroy the black hole by distorting gravity itself.
Grin Reaper Of Trolls this is good ? I'd like to know if someone has done the math
ty for asking it.
posted 12/8/12016 H.E (of the human era)
Shymen... kurzgesagt would be proud of you.
Moving faster than light (relative to a stationary reference) is certainly possible mathematically. And that means it is almost certainly possible in reality. The problem is the transition from sub-light to super-luminal. In order to attain such a velocity, you have to transition the actual speed of light you can't just instantly accelerate beyond it in an instant. And that particular velocity causes a division by zero in the equation that describes the energy/mass involved. So practically, it's not possible as you can't get past the barrier of c.
inside the event horizon, space expands into inself faster than outside, and all expansion is directed into the ingularity. So, if you are traversing that space, your only direction would be to the singularity
i love every space time video!!! thanks for another one. please never stop...
+No Name - by shell do you mean that their videos are released less frequently?
or that the content has declined in quality somehow?
No Name
oh that's a shame :(
@@fredlockard4509 THE ULTIMATE (AND CLEAR) MATHEMATICAL UNIFICATION (AND PROOF) REGARDING PHYSICS/PHYSICAL EXPERIENCE IS NOW DEMONSTRATED, AS E=MC2 IS F=MA: TIME DILATION ultimately proves (ON BALANCE) that E=mc2 IS F=ma, as ELECTROMAGNETISM/energy is gravity. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. (Importantly, balance and completeness go hand in hand.) The stars AND PLANETS are POINTS in the night sky. NOW, A PHOTON may be placed at the center of WHAT IS THE SUN (as A POINT, of course); AS the reduction of SPACE is offset by (or BALANCED with) the speed of light (c); AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Indeed, ultimately and truly, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS E=MC2 IS F=MA; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black. GREAT. Accordingly, INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/PHYSICAL EXPERIENCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. It ALL CLEARLY makes perfect sense. Gravity IS ELECTROMAGNETISM/energy. E=mc2 IS F=ma. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=MC2 IS F=MA. GREAT !!! Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS E=mc2 is F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Consider THE MAN who is standing on what is THE EARTH/GROUND. Touch AND feeling BLEND, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. The stars AND PLANETS are POINTS in the night sky. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Accordingly, the rotation of WHAT IS THE MOON matches it's revolution. Great. MOREOVER, a given PLANET (including what is THE EARTH) then sweeps out equal areas in equal times consistent WITH/AS F=ma, E=mc2, AND what is perpetual motion; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. Stellar clustering ALSO proves ON BALANCE that E=mc2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity. Objects (including WHAT IS the falling MAN) fall at the SAME RATE (neglecting air resistance, of course), as E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/energy is gravity. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 IS F=ma. THE DOME of a PERSON'S EYE is ALSO VISIBLE. (Notice the flat AND black space of what is THE EYE.) The stars AND PLANETS are POINTS in the night sky. The sky is blue, AND the Earth is blue. THE EARTH/ground AND THE SUN are E=mc2 AND F=ma IN BALANCE, AS ELECTROMAGNETISM/ENERGY IS UNIVERSALLY PROVEN TO BE GRAVITY in what is a mathematically unified fashion. E=mc2 IS F=ma. The middle distance in/of/AS SPACE AND the full distance in/of/AS SPACE are NECESSARILY linked AND balanced. MAGNIFICENT !!!!!!!!!! INSTANTANEITY IS thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. It is ALL CLEARLY proven. Again, the stars AND PLANETS are POINTS in the night sky. GREAT. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. It is all CLEARLY proven !!!!!!!! TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. GREAT !!!!!!!! BALANCE and completeness go hand in hand. By Frank DiMeglio
Einstein was a total weasel. Look hard at what he doesn't discuss. Learn to think for yourselves.
This lesson is beyond my current understanding. But I got enough of it to begin a wider understanding. PBS Space Time is brilliant and so so valuable - thanks for bringing this to us! PS I'm a PBS station member!
"She ripped a hole in our universe. A gateway to another dimension. A dimension of pure chaos".
Is that a quote from the movie event horizon?
- "A dimension of *pure..*
*Evil..."*
@@medexamtoolscom Yes. But the only correction is "She *tore a hole in our universe"
Where we're going you won't need eyes
Arthir C Clarke? Stanislaw Lem?
"Belief should wait on the evidence." An idea applicable across many topics.
No
@@moguldamongrel3054 Yes
Dare I say it, not just many, but EVERY topic. Except possibly things like pure mathematics, for which 'evidence' does not apply, unless you count mathematical proofs as evidence.
No. Say there's a business that just started up. Say it's selling popularly.
Say the evidence of numbers supports this. Are the numbers right?
Say there's a thousand bots on Yelp and really any platform designed to hype things. Say you can pay x amount to have a thousand Joe's and janes to drop positive/negative reviews. Say I already know it's true even without evidence.
Say I know alot of independent manufacturers put crypto miners on their computers. Say I have no evidence but I already know it's true.
Say that even the numerical evidence supports one thing whilst belief is true.
Lol No.
20 min? That's a legit short form documentary. Not just pop science video on YT. well done :)
Im saving this episode to the morning 😴
Okay, try not to kill any kittens till then
or turtles
elchucofried or cats
Hey Pat, don't forget to return those tapes.
I like to say thank you, most of this stuff is out of my league, buy you have helped me understand the basics. the universe is beautiful, thank you again.
10:00 - 10:25 Thanks for making use of the Shepard effect illustrating the "fall" in the block hole. What a cool idea!!
4:06 that was so damn coool!!
0:33 - Where we're going, we won't need eyes to see.
"🤔😑 What are you talking about?!"
😉
I cant follow any of this. I´ve never felt so dumb lol.
At least you admit it. Most dumb people believe they're intelligent.
Omg me too😩😩
4:38 - "super handy for understanding monkey's trajectories" lol
You mean there is no 5th dimension children's room in a black hole?!
jen sen There could be. Remember, that civilization had the ability to control gravity. Black holes are gravity.
MURPH!
jen sen I mean, if a human were to enter a black hole, they would be ripped to shreds. But you do you man.
Dan Howell ..No not all black holes would ripp you apart ..supermassive black holes , has somewhat less densities -like one in the centre of our galaxy..supermassive black holes has less tidal effects..supermassive I mean billion times the mass of sun. you will fall in just as the same as if you were to fall on earth
make him stay Murph! MAKE HIM STAY MURPH!!!
I’d give anything for the intellect required to truly comprehend and interpret this. Also, I like turtles.
The funny thing is that the "experts" don't fully understand it either
No you wouldn't.
Wouldn't it be cool if we could somehow move our earth into a blackhole!!! 🌎
@@Eiladel not if one bit him he wouldn't
The turtles go all the way down.
Just realized that's a great name for a nightclub. "What happens at the Event Horizon STAYS at the Event Horizon..."
That is the most beautiful Penrose Diagram I have ever seen. They just aren't as . . . neon on the chalkboard.
It's a great video when I need to repeat 10 second intervals every so often to digest what I heard.
"What happens below the Event Horizon… _stays_ below the Event Horizon."
Huh. Sounds familiar.
( ͡° ͜ʖ ͡°)
You can check out any time you like, but you can never leave.
Is that really your head in that emoji icon? If so, it appears your head has already fallen over the event horizon! A hairy turd ball that eternal black hole stuck a face on to try and make it easier to digest!
TCG Global Security Consulting jesus
@@VipestarHD nope but I met him once. He was mowing yards and landscaping in my neighborhood!
Ah, so this explains why my microwave clock is always ahead of my oven clock.
Brilliantly explained. Fascinating subject
you know you're a nerd when you get excited seeing this video in your feed
Jesus Christ
There's another "label" (word applied to the behavior of an individual), I could comment, based on your choice of web name and ego.
😏
The answer is....
*adolescent ego minded behavior*
Lol. I'm a big nerd then.
Dude could you ask your dad what the singularity is inside a black hole? And then come back to earth to tell us what it is, it could help us a lot. We won't nail you to a cross this time mate.
Repent
Thank you for speaking slowly!!!! :) now your videos are much better!!!! :) better to watch! because they are among best videos on youtube !! :) :)
Outstanding presentation
*opens video*
... the escape velocity reaches the speed of light.
*sigh*
*closes video*
It's a shame you didn't watch for about 5 seconds longer :(
The video is 20 minutes long. If you watch it you will learn something about creating assumptions.
Yeah, man. The "escape velocity" is the speed REQUIRED to leave the gravity of an object, and it's entirely possible for that to go beyond the speed of light, making it impossible to leave a black hole. Jeez. (but maybe OP was just being sarcastic)
exactly when i open my house door for my dog to go to take a shit
youxkio No~~~! It means that escape is impossible cuz light speed is impossible!
Well except for your dog, but ya get what I mean
OH BOY HERE WE GO
HERE COME DA BOI
You really did a great job in explaining the topic ... Thanks a lot!
19:42 I feel as if I could start an argument with that.
Edit - Hey look, I did!
No, please don't
So here we go! *grabs popcorn*
NO! I DONT THINK YOU CAN START AN ARGUMENT WITH THAT! YOU PIECE OF SHIT!
i disagree! profoundly cuz im right
"Why do you think ALL IMAGES of planets and space are cartoons??" It's a troll Runos. It takes a single google search to find a real life image of planets and space. Actually, does anyone have that link to the fucking INTERNATIONAL SPACE STATION livestream? It's really cool, seeing
This video messed up all my mind even bigger than watching memento, interstellar and Donnie Darko all together in one day.
That was a really cool movie.
1) If two black holes are close to each other will their event horizons deforms making them not spherical shape?
2) If answer to 1) is true, Is it possible to escape event horizon when two black holes collide ?
I don't think so it's called event horizon for a reason.
But if gravity is force and works similarly as electromagnetic force shouldn't force pooling you towards black hole between those two be equal zero. Moreover it be equal to zero on line perpendicular to line which contains those two black holes on it. Assuming that all mass in black hole is in its center, just before the collision will be line which goes through center of black hole to infinity on which the potential energy of gravity is zero.
Kuba Jurek I would think the event horizon still carries the same meaning.
No, once you're in the event horizon, you've been lost. However, the event horizons can bend, and you might find yourself some extra time by narrowly dodging the horizon if it bends in your favor. Or it could catch you by surprise not too long after you've barely escaped it.
I think you are correct, at a point exactly between the two black holes, gravity should be zero, and therefore that point should be outside the event horizon of both black holes. But how do you get there? When traveling towards it, you need to endure the gravity of *both* black holes, not sure whether the allows you to stay out of the event horizon of both.
Hey I've got a genius idea for the rescue mission! What about if the ship hangs out outside of the event horizon and drops a rope (always have a rope) down to the monkey PAST the event horizon, in that case we could easily rescue him and, in the meanwhile, break (correct I would say) the laws of physics.
Also, captain is played by Chuck Norris..
Philip Glenn de Catalina That is until I throw the other end of the rope into the neighboring bigger black hole...
Bet you didn't think about that huh? xD
TimmacTR, I would think that if the combined center of mass of the ship and monkey was outside the horizon then it would be possible. But if you had MacGyver, he could accomplish it with string, paper clips, and a ballpoint pen.
KsJayhawker94 Still interesting to think about it. The monkey would have a lot of stories to tell...though, the crew in the ship would be much older, so maybe it's the opposite.. xDD
Marik Zilberman I think it's interesting to think about it, imagining the rope is very though etc of course..
Basically, you'd have to put so much energy into pulling the rope, that it would have to pull the monkey, _faster_ than the speed of light, outwards. So, yeah, it won't work.
This is like one of those classes you love, but you still fail out of... I'm here for it
Each Space Time video is like being in 3-hour long, 7 consecutive astrophysics classes rolled into one package. Awesome!
Coolest thread I've ever seen on UA-cam is on this Video -
Ahhhhh there are cool normal people - they're in the Intelligent Tribe - on the Physics Channel!
⚛⚛⚛⚛⚛⚛⚛⚛
Just watching this after a 2 years again
“ Do you see anything at all when you cross into the black hole”? He’ll no because your eyes have already been ripped apart😉
Not necessarily if its a supermassive black hole
@@nothingbutspace8422 You'd still spaghettify, but after crossing the event horizon, rather than before.
@@upscaleavenue Yeah, that's what I meant
You’ve made a number of videos that address the standard black hole model. How about analyzing other models? I’m particularly interested in Abhas Mitra’s magnetospheric eternally collapsing object (MECO) model.
Much respect for the picture of The Event Horizon at the start of the video.
Thank you for making these videos! Among the many channels I often watch, this is the only one that consistently challenges me intellectually. There are some of them that I don't think I could understand even if I watched them like three times. :-D
F
H:
Oh my goodness, I never noticed they put they ship from Event Horizon on the screen with the definition.
And Battlestar Galactica was the monkey rescue ship
yeah not for the "faint of heart" good if you want a scifi horror
I have no clue what you are saying but I always watch all of your videos!
White hole?
So what is it?
MrRolnicek an object that spits out matter and light. Like a wormhole you go in one end and out the other.
White hole, spewing time, engines dead, advice please.
you dont go in and come out in one piece though...
I've never seen one before, no one has...
MrRolnicek A white hole is a theoretical yang to the black hole yin.
“What actually transpires beneath the veil of an event horizon? Decent people shouldn’t think too much about that.”
- Academician Prokhor Zakharov, “For I Have Tasted The Fruit”
This is so excellent!
The most interesting effect isnt what happens at the event horizon; but what we believe happens at the singularity....
Please touch on that subject in a future upload PBS.
When I need to remind myself how dumb I am, I watch this video.
Thank you guys
Event horizons are like Las Vegas, what happened at event horizons stays at event horizons.
Mastikator OMG😂😂😂😂😂
What about Herpes? can that escape an Event Horizon?
Mastikator the fuck
only bad jokes can escape event horizons
Mastikator lol!
"What actually transpires beneath the veil of an event horizon? Decent people really shouldn't think too much about that (about that)."
-- Academician Prokhor Zakharov, "For I Have Tasted the Fruit."
Thinking about things only gets you answers, and look what that leads to!
James Grose you need a working quantum gravity for that
These are always fun thought experiments
Thanks for the great videos. Here's a question about black holes that our group has had for more than ten years: If from the perspective of the outside observer, the person traveling to the black hole or anything else never crosses the event horizon because time becomes nearly infinitely slow from our perspective, then we observers should never observe black holes growing in mass. For instance, instead of observing super massive black holes, it seems that we should instead observe these black holes only as small black holes (as when they first came into existence) with enormous amounts of matter frozen just outside the event horizon. Even if a BH has collided with a neutron star, not enough time has passed (from our perspective) for the neutron star to have passed the event horizon. What are we missing?
Yes, I have the same question. Does it mean that we can see all that staff trying to pass behind the event horizon but never be able to pass? I saw something similar at DrPhysicsA but event more confusing he demonstrates the oposite.
@@nicu_danciu I never found an answer to my specific question. I probably could have worded it better. However, one thing that I did learn is that even before objects cross the event horizon, their radiated light would be stretched so much that they would no longer be seen as visible light.
''These are strange mathematical entities and probably aren't real at all.''
*slow clap*
A singularity means there is something wrong with your theory in that region.
I agree with the other replies that a singularity technically doesn't make sense and *probably* isn't actually a real thing BUT I will remind you all that you're not in charge and just because our mechanical brains don't like the sound of something doesn't mean it's not real. To quote Niels Bohr: Don't tell God what to do.
He's talking about the "Parallel Universes" and White holes not the Black holes themselves.
Very educational channel. Thank you for teaching me loads.
Subscribed.
Everyone talks about this event, none had the expirience of dreaming of being not even close to a sphere of this magnitude.
I have
@@michaelknight3613 you have to be brave_
That iam but I really have that and willing to share
So when you enter a black hole, space becomes time and time becomes space?
CornerrecordZ I didn't even think of that
perhaps not "becomes" but a very interesting viewpoint indeed
Time acts like space and space acts like time. They swap behaviors which leads to some very interesting things.
What Gareth said. The inward direction acts like the future direction. So, once inside the horizon, avoiding the singularity is like avoiding next Tuesday.
Wouldn't that mean that you can move around in time as freely as you move around in space right now?
Thru space and time....always another stroll wondering where I am lost without you....
Would it be possible to temporarily dip below the event horizon if two large black holes fly by each other close enough to overlap eachother's event horizon so one may ride the lagrange point between them? There's probably something missing like black holes that close would inevitably collide.
Most likely. would have to do the math and see if something like this is possible.
yep, don't understand any of this but that won't stop me trying 😂
Basically everything has an escape speed to leave its gravity earth does. You can’t escape a black hole because the escape speed meets or exceeds the speed of light.
Amazing clarification
Thank you for not dumbing this down or pandering to the lowest common denominator like most youtubers do ("not even light can escape guyzz..."). It's about time someone gave the viewers a small taste of the complexities of real astrophysics. And to people who crack jokes about not getting it watch it 3 times and you will.
It's cute that you think they're not dumbing this down.
There's always the asshole who think's they're smarter than everyone else. Intelligence isn't a measure of how much data you have in your brain, it's how fast or well you can process it and apply it. Being condescending and saying "It's cute that you think they're not dumbing this down" isn't a show of your superior intelligence, it is a show of your ego and insecurities regarding the democratization of information, that challenges your perception of intelligence.
I have a very important question : How does a photon "sees" the world? As it travels through the speed of light and as time stops at the speed of light, how can it moves through space without time? Does it access all time dimensions? Could it be in a dimension where the entire universe since the big bang is?
Yes.
I just looked at the channel bar and said out loud “Dude, how am I not subscribed???” I’ve been on a bit of a PBS Space Time binge lately, so I honestly thought I had already done it. 😂 Remedied 👍🏻
Nothing happens at the event horizon, theres no longer any frame of reference for observers to agree that an even happened in Spacetime
9:56 "Once inside the black hole, we could potentially see the monkey blow us."
Thank you for teaching us the Penrise diagram!
So, say I constructed a ship that could hover over the event horizon, I could theoretically experience less time than the rest of the universe? If I waited 100 years there, how many year outside of my position would go by? Is the bending your light cone to time travel?
Scryfish a lot.
If your ship could hover just outside there, it would need a great deal of acceleration to stay there against the infall of spacetime ... so yes, because acceleration slows your time rate relative to inertial reference frames, and a lot of acceleration slows it a great deal.
--Dave, just need to see it the right way to find the simple answer
If you had a really powerful warp drive, what would happen if you activate it when you hit the event horizon to try and escape?
I loved the movie event horizon. Glad to see you guys are fans of it too
9:55 I don't get it. If you and the monkey are travelling faster than light, how would you see anything? Wouldn't everything ahead be an infinitesimal point and likely blue shifted beyond obscurity?
ExaltedDuck You have to also take into account the relative speed of everything around you. If everything around you, including light, happens to be travelling at the same relative speed, you would see more. Unless of course everything around you is travelling faster than the speed of light all in the same direction, straight towards the singularity, well then you are right, you wouldn't see much of anything.
ExaltedDuck relative speed bruh. the only reason why when you are at some planet at the andromeda galaxy and you spy at someone from the milky way galaxy and they appear to be moving faster than the speed of light.
Light is always propagated in empty space with a definite velocity which is independent of the state of motion of the emitting body.
ExaltedDuck But what if there is a light source inside a black hole, past the event horizon in front of, or beside you. Is it possible, if the force is ever increasing leading to the singularity, that you would not be able to see the light source because of the increasing force bending the rays directly toward the singularity instead of into your retinas?
ExaltedDuck I mean we know the image on the event horizon appears to freeze, then slowly disappear, but past the event horizon, where the force is pulling light inward greater than the speed of light, wouldn't that make it impossible to see these light sources in front of or beside you?
What happens at tje event horizon stays at the event horizon!
I think this may be my favorite episode.
Hard to believe it was 7 years ago.
A few comments cued by the video elapsed times:
3:10 It’s not a “point”. First of all, it's not a part of existence, or as John Wheeler aptly put it: "There is no 'there' there". In yet another words, the singularity in the Schwarzschild black hole is not a _place_ but something like _tomorrow_, i.e., everywhere in your future.
6:29 Not true - the lines of constant space and time do not switch. This is a common misunderstanding and I'm surprised this error has made it here: (a) that "switch" is purely man-made, it's simply a property of a certain coordinate system, i.e. our human bookkeeping system. It's not anything real and is simply a consequence of lazy re-use of coordinate _labels_ while solving the Einstein equation for the black hole. In good textbooks (like Hawking & Ellis for example) the relevant letters/labels are kept "straight" precisely to avoid this confusion. (b) Moreover, in the video this is mentioned while showing the Penrose diagram which is a type of coordinate system where this switch does _not_ occur anyway.
9:50 It should have been simply stated that the effect of the monkey appearing frozen at the horizon is purely an optical effect, not unlike a fatamorgana, due to the light signals being delayed.
10:35 Work on the pronunciation of “Schwarzschild” some more :-) Hint: "w" is pronounced as an "f", "z" as the "zz" in "pizza", and "Schild" means "shield" and is pronounced likewise (but that final "d" is like "t"). His name means "black shield" - really!
11:25 Big bonus points for finally mentioning the rotating (Kerr) black hole. Since FAPP all the black holes in the universe (if they exist as predicted) are rotating, it is indeed weird that virtually all pop-sci presentations ignore it and focus exclusively on the nonrotating (Schwarzschild) case which is a bit like a pencil standing on its tip: possible but unlikely to have the angular momentum exactly zero! The reason rotating black holes are interesting is that according to the classical (non-quantum) theory _they are not fatal_: the singularity is actually quite _hard_ to hit, any object free-falling into it would have to follow an _exactly equatorial_ trajectory in order to hit it, in fact the singularity itself, which is in the shape of a ring, is strongly gravitationally _repulsive_. But given enough initial push one could fall _through_ that ring into another universe. If the mass of the black hole is large enough (about 400 million solar masses, say) the falling object would not feel _anything_ while falling through as the tidal forces would be about equal to what you are experiencing right now as you’re reading these words. As I said, for some odd reason pop-sci books never discuss Kerr black holes despite all this intriguing weirdness, I could go on like this for a while but the margin is too small to contain it :-)
JanPBtest You seem to know a lot about this! Are you an astrophysicist?
First off: Awesome constructive comment for a youtube video! About the 3:10 part though (note: this stuff is just all hobby and interest for me so I don't intend to claim I know better), for me it's easier to actually imagine it as a infinitely small point with infinite density etc. instead of... a everywhere :) Isn't that also what is usually told to people? Do you have any sources so I can read more about it though? I'm interested in finding out what you exactly mean by that!
No, a mathematician but been more into physics for many years.
What I meant was that two (say) _pointlike_ objects falling along the same path down but at different times will both end up crushed but at different locations. The spatial region inside the horizon is, strangely, not a 3D ball but a homogeneous 3D space of infinite extent, two dimensions of which form spheres, so the whole region inside is, at every instant of time, like an infinite "row" of spheres, with entire row having smaller and smaller radii as the time passes. Because of that the object cannot "visit" this region at will because with every instant of passing time the object finds itself in one of those spheres of smaller and smaller radius, until it's crushed. So different objects get crushed in different places.
Question.
What the fuck happen at the event horizon and below the event horizon when 2 black holes merge?
Magic!
I think it would be like merging two droplets
ballom29 I know , it's like mixing two very very very viscous liquids together .
The 2 black hole's event horizons start to bulge out slowly towards each other , after getting closer in terms the space outside of the horizon the space time stretches and stores the energy in the form of stress and just after the signal from the singularity merger reaches the gooey horizon the boom the energy is released as humongous gravitational wave .
In the core however I think the singularities somehow fight for survival until one of them have to get soaked up out of existence. 😓
They probably fall towards each other very very fast. And when they're less than a Planck length apart they just merge into one.
I wonder too. If they are both spinning in the same direction, and event horizons touch at the equator where the matter just outside of the event horizons has opposing trajectories and past which none of the matter can escape, wouldn't the program crash due to a math error, or result in such a big energy release that the universe has actually already been destroyed and this is in fact the afterlife?
My thought is that what happens inside of an event horizon must follow drastically different circumstances relative to what happens outside of an event horizon, or rather follow a logical path that makes the circumstances outside irrelevant to the circumstances inside, because while they're merging, the surfaces would still be theoretically moving in opposing directions on every part of the surface that has not merged. Inside, it must be a different story which must be conceived in different terms.
Imma' retract somewhat though. Maybe it would be more likely that they would spaghettify each other prior rather than 2 spinning blobs grinding against each other? Or the more massive one spaghettifying the smaller one and warping only slightly itself? This would probably look like a swirl to an outside observer, but would probably be less skewed (If at all) from the perspective of the local space that the matter inhabits.
I'm pretty much wildly pontificating at this point, and Imma' stop.
This vids are georgeous
I have crossed the event horizon of understanding what he is saying 😂
So, could light go into orbit around a black hole at the event horizon?
Yes. See photon sphere. For Schwarzschild, this is actually at 1.5x the event horizon radius.
That's a interesting thought: would it all just turn superwhite and hot when closing in to the horizon?
It would not. Although photons can in principle orbit the black hole at 1.5x the event horizon radius, those orbits aren't stable, so very little light is actually trapped there.
That said, real astrophysical black holes are almost never isolated. There's a lot of stuff that falls in -- even the intergalactic gas would be superheated and glow very brightly (even in x-rays) as it falls in, and that radiation would be lethal to you as you approached. Funny thing about black holes -- they're the darkest places in the universe, but the region immediately around them is also among the brightest in the universe.
Why 1.5x?
Math.
This is it everyone! With a video title like this one, you just know the mystery has been solved forever
Is time really an illusion?
I'll tell you tomorrow.
Time is not, it's simply entropy in effect. But the perception of time... oh dear yeah this is one big illusion.
time is what happens to stuff. if there is no stuff for events to happen to them there is no time ^^ but then there will be no one to notice that
Yes
Everything is an illusion
i have 2 questions about escaping a black hole. first if you had an alcubierre drive could you pass through the hirizon and back out or would the warping of space time interfer with you drive. second if you had a wormhole and you took one end into the black hole could you use it the get out of it and see yourslef frozen at the horizon.
wow the second one is pretty good , that would be like cutting a hole through another hole in the very fabric of space-time , it is mind boggling really
Great question. Seems possible.
this might sound ignorant, but the explanation of a black hole makes me think of a common drain that one might have in a sink or tub. as the water or liquid and any substance that happens to be floating or below the liquid gets closer to the drain, not much happens other than the flow is pulled to the spiral created by the drain. once the liquid and substance in said liquid enter into the spiral, they do become entangled and twisted as they enter farther and farther in until there is a single stream if you will. this does make you think and the similarities between how liquid acts as it enters the spiral of a common drain and the workings of a black hole could indeed make it easier to understand.
So if you crossed the event horizon, would you be blinded by light that was trying to get back out? And because spacetime is warped down to a point, are there an infinite amount of successive event horizons between the initial one and the singularity?