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Black Holes & Information Paradox · Acedra
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Black Holes & Information Paradox
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0:00
what's going on my friends welcome back so today we're going to watch another kurzgesagt video before we get into it two things one uh the alpha for kelvpn my quantum proof vpn it's essentially ready we're just trying to implement a way for you guys to be able to log in when you download it so everything works we're doing this so we can test uh you know all the stuff on our side and so
0:18
it'll be free so that's exciting so next week is what we're aiming for uh and then the second thing i can finally tell you guys what i'm planning for this second venture i've mentioned before so if you guys have ever read morning brew you'd get a pretty good idea of what we're gonna try and do so it's completely free we're gonna this will all be completely free you just sign up with your email and we'll send you an email every single day with our newsletter the daily dance and it
0:43
will be like uh bullet points there'll be some memes quotes and it's gonna break down the newest science with links maybe in bullet form and the latest on business geopolitics world business as well as new tech that's emerging i think this could be really useful for people in business for people who are just passionate about keeping up with science because there's not really it's not done well anywhere really so i'm super excited about this it's
1:09
going to be completely free to you guys kind of already do it in my head every day i love i'm passionate about keeping up with what's going on in science whether it's space physics everything i love it and then combined with that what i'm gonna do is then live stream on twitch me reading our daily newsletter every single day and then with that stream i can you know chat with you guys and watch youtube videos do whatever right and then i'll upload them to youtube as well so
1:36
i think that'll be a fun little system apparently it's a national girlfriend day so i just want to say a big hello to all my girlfriends out there that's a joke black holes are the most powerful things in the universe strong enough to rip whole stars into atom sized pieces while this is scary enough they have an even more powerful and dark property they might delete the universe itself
2:11
black holes in a nutshell a black hole appears when an extraordinary amount of matter is concentrated in a tiny space at their center gravity is almost infinitely strong and whatever gets too close is ripped into its elementary particles you know how i do it i just like to nitpick everything it is infinitely strong at least according to the equations of general relativity not even lights can escape black holes and so
2:37
we perceive them as spheres of blackness if you were to fall into a black hole nothing bad would happen until well after you crossed its outer border the event horizon you can also not true you can actually get crushed out there's all sorts of things that can happen to you before you cross the event horizon imagine this as swimming in a river that ends in an enormous waterfall as you
3:00
float along imperceptibly the stream gets faster and faster even if you can't see the waterfall yet you could swim to safety until without even noticing it you cross the point of no return no matter how fast you try to swim now the stream will pull you towards certain death nothing can escape a black hole waterfall once it gets too close here's something you might not know dark energy can actually escape a black hole no matter what size the black hole is and no matter
3:28
how close the dark energy is to even the center of the black hole this is because dark energy isn't affected by gravity at all dark energy is what causes the universe to expand faster and faster we think so this means it actually has an effect opposite of gravity since gravity pulls things together right the only thing in the universe as far as we know that is not affected by supermassive black holes have you ever wondered if black holes eat dark matter well if you do the
3:54
math you'll actually find that black holes will use both normal matter and dark matter as like a food source but the normal matter will dominate the growth of the black hole even over like enormous cosmological time scales even when the universe is like a billion times older than it is right now black holes will still be like 99 normal matter and less than one percent dark matter
4:17
so dark matter is not really a good food source for black holes nor is it like information wise an interesting one so what what it gains from eating dark matter is not really any different from like shining a flashlight into it this border completely separates black holes from the rest of the universe if you want to know what happens to someone who falls into a black hole you should go check out the other video that we reacted to of course because i'll put a card up on the screen
4:44
if you want to access them unless we're willing to never return so there's no way of telling what's really going on inside black holes but we have a few ideas about what's going on right at their very edges black holes radiate their mass away like a hot pot on a stove losing its water esteem
5:02
this is called hawking radiation black holes constantly lose an extremely tiny amount of their money i think we're going to have to talk about hawking radiation a bit in this video so we'll get there but let's do some more watching and yeah maybe i can actually give you guys a bit more information as to what's really going on because if you watch the other ones i've told you the common uh explanation that people like to give even including hawking himself
5:25
is a kind of a lie it's like a simplification but anyway let's keep watching for now a process that's unbelievably slow it will take it's just visualizing just then like that's that's not what's really happening like a black hole with the mass of our sun 10 000 billion billion billion billion billion billion years to lose 0.00001 percent of its mass this is happening constantly and unstoppably and as it goes on it
5:53
speeds up more and more in the far far future when the last star what he's showing it's not actually what's happening so in 1974 when he famously derived hawking radiation the first time ever this was the calculation that he made he calculated the difference in the zero point energy in quantum fields from curve space around the black holes to flat space infinitely far away so the result
6:17
of this was what determined the properties of the radiation that come from black holes not from the event horizon exclusively but from the entirety of the curved space around it so the major problem with the explanation that he gave of his own theory is that he takes a calculational tool the idea of these virtual particles and treats them as though they're equivalent to physical reality in reality what's actually happening is that the curve space around the black
6:42
hole is constantly emitting radiation due to the curvature gradient around it and that the energy is coming from the black hole itself causing its event horizon to slowly shrink over time right so black holes are not decaying because there's an infalling virtual particle carrying negative energy that's another fantasy that he explained instead black holes are decaying and losing mass over time because the energy emitted by this hawking radiation is
7:08
slowly reducing the curvature of space in that region once enough time passes and that duration is enormous for realistic black holes they would have evaporated entirely right so this hawking radiation is not the emission of particles and anti-particles from the event horizon it does not involve an inwards falling pair member carrying negative energy and it shouldn't even be exclusive to black holes but for trillions of years black holes will become tinier and tinier
7:36
until they evaporate and disappear leaving behind just a bit of radiation but this is a problem because in the process of disappearing black holes might delete something fundamental information two what is information information is nothing tangible it's typically understood as a property of the arrangement of particles what does this mean imagine a bunch of carbon atoms arrange them in a certain way and you get coal arrange them in a different way and you get a
8:06
diamond the atoms are the same what changes is the information if we make this more complex and add in a few more atoms we get a banana change the arrangement of the atoms and we get a squirrel
8:21
the basic building blocks of everything in the universe are the same and part of a bird or a rock or a cup of coffee without information everything in the universe would be the same
8:33
according to the theory of quantum mechanics information is indestructible it might change shape but it can never be lost for example if you burn a piece of paper you get ash that ash will never become paper again but if you were able to carefully collect every single carbon atom in the ash and measure the exact properties of the smoke and heat radiating from the fire you could in theory reconstruct the paper the information of the paper is still in the universe
9:02
it's not lost it's just hard to read if you could somehow measure every single atom and particle and wave of radiation in the universe you could see and track every bit of information there is hypothetically you could see the entire history of the universe right back to the big bang and here black holes trippers up information tells us how things are different from each other and what used to be what black holes do the opposite they take different things and make them the
9:34
same they destroy information this creates the information paradox and this is a serious problem
9:45
the information paradox there's been a bunch of proposed solutions to this information paradox and we'll talk about a few in spaced out over in this video including the firewall paradox uh where information is assumed to burn up before it enters the black hole the string theories fuzzball solution where black holes are thought to have like interesting boundaries and two others plank stars and first we'll talk about right now
10:09
so a lot of those solutions require rewriting the laws of quantum mechanics or einstein's theory of gravity the two pillars of modern physics right whereas this quantum hair theorem might be able to do it by bridging the gap between general relativity and quantum mechanics using like a new mathematical formulation right so black holes might just be more complex than we thought or hearing so as matter goes into it falls into it it leaves like
10:35
this faint imprint in the gravitational field this imprint is referred to as quantum hair and will provide like the mechanism by which information is preserved during the collapse of a black hole but unfortunately there's no obvious way to test this theory like with astronomical observations the gravitational little fluctuations would be way too small to measure there'll be a lot of scrutiny
10:56
though in the theoretical community with this so i guess this is fairly new so we'll see what happens
11:03
it's fundamental for all our laws of physics that information can never be lost existing not existing without information everything is relative when it comes to our understanding of reality we need absolutes how can we solve this paradox there are a few possibilities one information is lost irretrievably and forever this means we have to mix all our laws of physics throwing out a lot of stuff that's
11:32
worked very well so far and to start from scratch what those new laws of physics would look like or what that means for us nobody knows this is a little frightening but also kind of exciting
11:44
two information is hidden maybe a little part of the black hole splits off and forms a baby universe the information would be transferred into this new weird place where we could never observe or interact with it but technically it would not be lost it's like having a broken hard drive with all your family photos that you could never access sure it's nice that they've not been deleted but
12:05
also not very helpful or maybe black holes don't disappear completely after the end of their life cycles but a little piece is left an information diamond so what about if black holes are fuzzballs this would also resolve the information paradox because in strength theory we found that all the mass black hole is not getting sucked into the center the black hole tries to like squeeze things
12:27
to a point but then the particles get stretched into these strings and these strings start to stretch and expand and it becomes this fuzzball that expands to fill up the entirety of the black hole all right that's enough of the fuzzball stuff because there's still absolutely no evidence for strengthening if everything that falls into the black hole is stored on its event horizon like a clown car filled with an infinite amount of information clowns but there's a third option
12:52
information is safe after all not lost or hidden perhaps we've just been looking at this whole thing the wrong way we know the black holes trap information and might delete it later but we never thought about what they do with it in the meantime where do black holes store their information
13:11
plane starts so they're these theoretical objects in which a massive star breaks down and what would typically become a singularity where the density of spacetime is infinite meaning nothing can escape instead becomes this plank sound where the collapse is basically stopped by a former repulsion that's created by energy density coming from the heisenberg's uncertainty principle before the object reaches an infinitely dense point this basically results in an object that's not much
13:37
bigger than the plank link which happens to be the smallest like possible measurement so because this replaces an inescapable singularity with something just really small but not infinitely dense just bigger than the plank scale but not by many magnitudes it would resolve a lot of paradoxes
13:54
surrounding how matter and energy work around black holes but not without creating some new questions obviously along the way so it does away with the information paradox because there's enough volume and density you know playing star to basically make sure that information about matter and the quantum states about matter that you know gets swallowed by a black hole don't get destroyed
14:13
weirdly though believed that these plank stars in the middle of a black hole would continue to grow if mata fell in kept falling and so basically the plank style would consume so much that it would intersect with the event horizon causing all this information to be like expelled in a flash and finally the plankster would also do away with the firewall paradox because there's a bunch of interesting implications for how the universe like might bounce and crunch cosmic housekeeping
14:44
let's create a black hole with dirty laundry first we fill up a room with laundry baskets the more laundry you want to store the more baskets you put in the room but at some point every single basket is full and the room is completely stacked not a single extra sock fits in the room is at maximum capacity but if we still squeeze the sock in with a lot of energy and violence the room collapses in
15:09
on itself and forms a black hole but the capacity of the room itself has not changed fitting in more stuff or information is still impossible so what happens if we throw more laundry into it
15:22
the room itself gets a little bit bigger to make space for the new information it turns out a black hole grows its surface by a tiny pixel for each bit of information we throw into it
15:33
in a nutshell more information means more surface area the information gets painted on the surface similar to what happens when we throw a stone into a pond after the stone sinks to the bottom we can't see it anymore but we can tell that something went in from the ripples on the surface of the pond even the smallest black hole can store more information on its surface than all the data ever produced in human history they do this by storing information in a type of pixel that is
16:01
unbelievably tiny black holes are the ultimate hard drive this is a bit like taking a paperback and turning it into an ebook two things that look completely different but their content is the same it's just encoded and memorized in another way black holes swallowing stars and planets is a bit like transferring a whole library onto an e-reader this solution is called the holographic principle but if it's correct then everything we thought we knew about the universe is wrong
16:35
the universe is a hologram
16:39
if information is actually stored on the boundary of a black hole the hawking radiation has a chance of learning about the information encoded there and can carry it away it's one thing to ask how can you decode the hawking radiation but you also might ask how complex is that task to do that well it turns out it's extremely complex there's some fun proposals uh called the python's lunch that
17:04
explains how you might actually be able to do it so information is not lost when black holes fade away and we do not need to redo physics the information paradox is resolved but we still have to change our understanding of reality in a fundamental way all right let's talk about this firewall paradox so like in 2012 the firewall paradox kind of got like this reimagining it the firewall is like this hypothetical phenomenon where someone falling in would
17:30
encounter like a high energy high energy quantum essentially at the end at the event horizon conventionally we'd pretty much assume that if a black hole is large enough someone falling wouldn't notice anything unusual as they fall in but in this scenario which we call the no drama the gravitational forces wouldn't be extreme enough until you get to the point inside the black hole called the singularity right but if that's correct as someone crosses the event horizon
17:56
so if this firewall paradox is correct as someone crosses the event horizon they'll pretty much encounter like a massive wall of fire that will incinerate them on the spot right no one's been able to explain though exactly what happens when a black hole consumes particles or how information might be might leak out of a black hole in the form of like contour right the traditional understanding has always said that all matter consumed by a black hole would immediately be lost
18:23
to outside observers once it sucked into the event horizon an astronomer basically figured out that if entanglement between an involving particle and the outgoing particle was like broken then a bunch of energy would be released creating this black hole firewall at the event horizon and that would prevent us from observing the information other physicists have even proposed that the outgoing and infalling particles are somehow connected by like wormholes that basically
18:49
means that three-dimensional stuff is encoded on a flat surface we have a name for this a hologram a hologram is like a 3d photo a flat piece of plastic that encodes a three-dimensional image a black hole is like a hologram because everything inside it is encoded on its event horizon a person inside a black hole would experience their usual three-dimensional life but for us on the outside they are flattened images on the surface of the black hole
19:17
the consequence of this is counter-intuitive but stay with us for a moment black holes are very extreme objects but they're still bound to the same rules as everything else so if this crazy duality between 2d and 3d works for black holes then it might work for the whole universe and you in it since a person inside a black hole would not realize that they're encoded on a flat surface we might share the same fate you really might be stretched over a flat
19:43
screen at the end of the universe the science behind this is complicated and really weird with toy universes to play with string theory and a lot of maths we'll talk about this more in another video regardless of what the true nature of the universe really is we just know that it's strange and complicated and we have to do a lot more physics to understand it but black holes might be key to understanding the nature of reality itself this video was supported another
20:14
great video about kyogre zach i enjoyed that hope you guys enjoyed i'll catch you next time
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