HEY! The man knows comfort, and practicality. It is unnecessary and inefficient for him to wear a suit and tie for what, to stand in front of a chalkboard and talk to a bunch of college students? IMHO it would be fine if he walked into class wearing a goddamn bathrobe and shower sandals.
Casual Friday To do list: 1. Do some laundry 2. Get the Groceries 3. Walk the dog 4. Jogg 5. Give a lecture on Quantum Physics 6. Grab a cold one with the Bois
He looks, and sounds, a great deal like Mike Ehrmantraut from the tv show "Breaking Bad" and "Better Call Saul." It's amusing to imagine a world class physicist moonlighting as a bodyguard.
This guy Leonard explains physics better than most people I've found on the entire internet. Thanks for taking the time for the impromptu lecture. Seriously better than most planned and scripted videos I've found on black holes and quantum physics
Hundreds of thousands of guys listening to what a guy with shorts and slippers have to say and he´s not a football player. This is what respect should mean.
Because of the audience do not respect him by eating during the lecture, that's why he can afford to yourself lecturing wearing that funny shorts and slippers. The country in which nobody respects each other
I'm gonna admit it, I am touched by this presentation. This is the very beauty of the human race. Intelligent people working together to understand the world they live in. keep learning!
@@qpwodkgh2010 it's quantum mechanics, I don't recommend it to kids also i think feynmann was a great teacher but he also won't be able to explain the mathematics of QM to a 7-year-old kid, unless that kid is a born genius.
Computer science graduate here. I had very little info on black-holes and after watching this video i'm pretty confident that i can talk about it. What a great teacher
A black hole exists in computer too, I associate it with finding the gate that gravity will cease to exist when there is no restriction or too much gravity and time gets stretched when gravity oppresses mass into a pinpoint hole that flips the poles, what we know as matter into antimatter. What does it turn into? A mirror image = v^1.
man, what I would give to sit around a table eating lunch and discussing black holes with other people who are interested. thankfully this was recorded
🎯 Key points for quick navigation: 00:05 *🎭 Unprepared Introduction and Audience Composition* - Susskind humorously acknowledges being unprepared and describes the mixed background of the audience, including biologists and astrophysicists. - Expresses surprise about the lecture setup, expecting a casual discussion rather than a formal presentation. 01:29 *🧩 Addressing Black Hole Paradoxes and Quantum Gravity* - Introduces the talk's focus on understanding paradoxes, particularly around quantum gravity and black holes, which have challenged scientific theory for decades. - Describes paradoxes as potential keys to new scientific insights, especially when theoretical concepts conflict. 04:22 *🌌 Quantum Gravity: A Unique Connection* - Discusses quantum gravity not as simply “quantizing” gravity but as a deeply interconnected phenomenon where gravity and quantum mechanics cannot be separated. - Highlights how traditional methods of applying quantum mechanics are ineffective for gravity, signaling the need for new approaches. 05:40 *🕳️ Black Holes as a Natural Test Bed for Quantum Mechanics* - Emphasizes that black holes provide an ideal setting to observe quantum mechanics and gravity together, as their nature is fundamentally quantum. - Explains how black holes reveal surprising properties that may help bridge the gap between quantum mechanics and gravitational theories. 08:13 *⏳ Tension Between External and Internal Black Hole Perspectives* - Describes how time and space behave differently at a black hole’s event horizon, creating a paradox for outside and inside observers. - An observer outside sees objects slow down near the horizon, while the infalling observer experiences a finite amount of time, illustrating the limits of classical descriptions. 13:03 *🔍 Classical Infinite Information Paradox* - Explains that classical physics suggests infinite time and infinite information storage near a black hole’s horizon, a puzzling implication for entropy. - Notes that black holes would theoretically store infinite information if not for the finite entropy principle, a realization credited to physicist Jacob Bekenstein. 15:11 *🧮 Bekenstein’s Argument on Finite Black Hole Entropy* - Introduces Bekenstein's revolutionary concept that black holes have a finite entropy, proposing that information is limited even at a black hole’s horizon. - Describes Bekenstein’s thought experiment of adding information bit by bit, ultimately limiting a black hole’s entropy by the horizon’s surface area. 20:02 *🔑 Building a Black Hole Particle by Particle* - Susskind walks through Bekenstein's process of constructing a black hole from individual particles, each contributing finite information, to illustrate entropy limits. - Shows that each photon’s entry into the black hole increases the horizon area, creating a calculable relationship between entropy and area. 24:30 *🔍 Quantitative Details of Bekenstein’s Theory* - Provides the mathematical relationship Bekenstein used to derive black hole entropy, emphasizing that each bit of information increases the black hole's area incrementally. - Explains how Bekenstein’s calculations refined the understanding of entropy, grounding it as proportional to the horizon area and finite rather than infinite. 26:29 *🔑 Finite Limits on Black Hole Entropy* - Bekenstein’s discovery that black holes have finite entropy, later supported by Hawking’s work, introduced the concept that entropy is proportional to the black hole’s area rather than its volume. - The relationship between entropy and temperature was also defined, with temperature inversely related to black hole mass, a unique quantum effect. 31:03 *🌐 Black Hole Structure and Entropy Observations* - Describes the “stretched horizon,” or thin shell where entropy appears stored, suggesting black holes as hollow spheres with temperature depending on proximity to the horizon. - Entropy being proportional to the area rather than the volume implies limited “interior” content, leading to questions about reconciling inside-outside perspectives. 34:55 *🌀 The Holographic Principle and Black Hole Interior Representation* - Introduces the holographic principle, theorizing that black hole information on the exterior could represent or “encode” the interior, likened to a hologram. - This theory proposes that information on the event horizon could correspond to internal elements, encapsulating the black hole in a boundary structure. 37:19 *🌡️ Evaporation and Quantum Dilemmas of Black Holes* - Explores how a black hole’s radiation during evaporation complicates entanglement relationships between interior and exterior regions. - As radiation escapes, distant radiation becomes entangled with the black hole’s interior, violating quantum mechanics’ principle of “monogamy of entanglement.” 42:16 *🔥 Firewall Theory and Entanglement Conflicts* - Firewall theory suggests that entanglement disruption between black hole interior and radiation creates a “dead end” for infalling matter, questioning the existence of an actual interior. - Though debated, some researchers, including Susskind, see the firewall as overly simplistic, implying more profound mysteries about quantum-gravitational connections. 47:00 *🔍 Quantum Entanglement as a Core Principle in Physics* - Quantum entanglement’s complexity lies in the paradox of knowing everything about a system but nothing about its parts, a notion Einstein found troubling. - Now integral across various fields, entanglement is central in black hole physics and other domains, marking an “infection” of ideas that continues to reshape theoretical physics. 54:18 *🔥 Firewall Theory and Entanglement Disruption* - Breaking entanglement between two entities, A and B, near a black hole’s horizon requires energy, which could lead to a “firewall” effect-intense radiation at the boundary that disrupts the vacuum structure. - Quantum mechanics complicates this as disentangling may force the vacuum state to heat up, potentially altering how we view horizons and event boundaries. 56:09 *🌌 Information Flow and the Black Hole’s Expanding Horizon* - As information (like photons) enters a black hole, its horizon expands slightly, absorbing new information into its “stretched horizon.” - This process aligns with the holographic principle, where exterior information is encoded on a boundary rather than passing fully into the black hole interior. 59:11 *💫 Entanglement Persistence and Holographic Analogy* - Discusses the persistence of entanglement when one of a particle pair enters a black hole, likening it to image charges in a mirror. - Entanglement remains, possibly with the black hole’s stretched horizon or an interior holographic image. 01:00:35 *🌠 Impact of Black Hole Size on Interior Analysis* - For large black holes, such as those in galaxies, the central singularity is less impactful on the region near the horizon. - This allows scientists to study black hole boundaries independently of singularities, focusing on accessible areas near the event horizon. 01:03:05 *⚛️ Hawking Radiation and Quantum Entanglement* - Hawking radiation, mostly photons and gravitons, could hypothetically carry black hole information outward, sparking debates over whether reintroducing this radiation affects the black hole. - Entanglement with the outgoing radiation complicates how information and entropy are balanced, highlighting the paradox of reconciling entanglement on both horizons. 01:06:03 *🌀 Quantum No-Cloning Theorem and Information Identity* - Black hole physics challenges the “no-cloning theorem,” which states identical quantum states cannot be replicated. - Proposed theories suggest relationships between internal black hole structures and distant radiation, but exact identity between information zones (like A and B) isn’t possible without breaching this principle. 01:07:26 *🌊 Analogy of Dumb Holes and Black Hole Sound Models* - The “dumb hole” analogy uses sound in a fluid as a proxy for black hole behavior, though it fails to fully replicate information retention. - While this analogy provides a conceptual look into black holes, it lacks the complexity of true holographic and entanglement features. 01:08:37 *🧩 Partial Entanglement as a Proposed Solution* - Partial entanglement (where entities are only partly connected) doesn’t fully resolve the paradox since black holes demand maximal entanglement between zones near the horizon. - This partial connection model introduces gradations in entanglement but remains insufficient for practical black hole theories that assume total or maximal entanglement. Made with HARPA AI
Photon sphere is the stretched horizon around the black hole, and if you take the circumference of the photon sphere multiplied to Boltzmann’s constant divided into h*c, it will give the photon temperature. Photons which have this wavelength that equals to the circumference of an object are what I like to call winding or circumferential photons.Try taking the momentum of a photon which has a wavelength equal to the electron circumference divide it into the electron mass multiplied to c it will give the fine structure constant. Divide the electron circumference by alpha, you will derive the electron Compton wavelength. In my opinion this is why the fine structure constant exists because it was necessary in decreasing the wavelengths of high energy photons to help them undergo photon pair production from energy into matter.
_THIS_ is a perfect example of pure confidence from someone who without a doubt knows their sh!t: Totally underdressed yet doesn't give a damn what anyone thinks about it and ALSO being able to "wing" an hour+ talk after being given two days prior notice on what is a barely comprehensible subject. We should ALL strive to achieve something in our own lives that at least RESEMBLES what is seen here.
I love your enthusiasm. And I wish I shared it . . . in my opinion, this style of presentation falls way short of earning your level of admiration--though I totally agree he knows his field. If you have time, try a "Cool Worlds" video from David Kipping, of Columbia's astronomy dept. He is my dream professor. I'd very much respect your impression. This is one of his best videos--
He talks highly of Einstein and by that he is bias because he doesn't show the experiment, so I too agree what really can he prove other he can explain.
chazz Lucas it’s not bullshit, it’s a very hard topic to grasp, they are trying to simplify it the best they can. If you don’t understand then I suggest to go look at some basic physics lessons and improve, this is way too complicated to understand for you right now.
16:10 Here we’re trying to understand acceleration; we have a funny situation ... that requires meditation; or we’d suffer constipation. Susskind, the treasure of a nation; most others mere regurgitation. Front row sandwich fidget frustration; Breaking Bad hit-man confrontation. Ocean and body acidification; steady camera congratulation.
Bit Finesse Massive time dialation, constant conceptual preoccupation; Yet consumed we are by the TV stations. SpaceX and hopeful inclination to space exploration; seems we are a dying nation. Stumbling upon Susskin is quite the revelation, when you become aware of your station in the equation. The temptation to revel in security of false salvation is one to be reckoned with, not taken for a fools paplation.
@@DylanZapf-dm4mh Bit Finesse this is a very interesting semantic exploration of your superb creative imagination rising from my deep slumber of mindless procrastination, i am writing you this note of appreciation but please forgive my excessive dramatization as i present this note as a compensation for my lack in literary education
I did keep scrolling up and down waiting for the chalk to start going onto the board and noticed that. Its a mixture of smart and dumb comments. I did notice that the guy wearing the sandals took them off at some point around the 20:00 mark... haha
I was and it is all a bunch of fabricated lies.... Gravity, Relativity and everything claimed by "Science" over the last 200 years is 99% bullshit..... Wake up and do your own research
I have watched a bunch of Susskind lectures. I thought I had gotten to the end of his points with the holographic /black hole angle. Now he brings in an entirely new physics. Just amazing. And very easy to listen to, in the Feynman model.
I could listen to Susskind forever. He's brilliant. Anyone who held court with Feynman is a hero of mine. Feynman liked him too. His Stanford UA-cam series are fantastic!
koldfushen Well I'm a scientist too. Please leave Richard out of this discussion if you cannot back up your claim. Richard would want it that way. You know I'm right ;-)
40:18 interesting. so you could probe the interior of black holes with quantum entanglement? but more importantly does that mean that if the observable universe was the interior of a black hole, then we could probe the exterior.
I enjoyed listening to this while doing other stuff. It was similar to my college experience in so much as my brain was elsewhere while smart people talked.
He isnt the best teacher. Like most colleges, they hire super smart people who know their shit, but unfortunately a lot of them are poor at communicating complex concepts.
@@Scorch428 I disagree! I have watched a couple hours of UA-cam (shorter intro videos on string theory, entanglement, black holes, etc) and i obviously don't know as much as him, but i consider him very interesting and actually a *great* lecturer. Especially considering that this appears to be a special topics one-off lecture, not a course. It serves to give a primer in 1 hour and pique interest in the subject.
Question: if nothing ever seems to fall into a black hole as viewed from the outside 11:00 then the black hole is never observed to grow. Stuff falling in should increase the event horizon radius, but only *after* it passes the horizon right? Is that a problem or am I just confused?
maybe someone can help me on this: by 26 minutes we did this: Schwarzschild Radius R = 2MG/c^2, The change in mass from a photon with wavelength=R is noted by M=h/Rc, plug into the Schwarzschild radius to see change in radius --> RR'=2Gh/c^3., which is equal also to its change in the area of the black hole, A. Then Susskind says that based on this, "the change in the area of a black hole due to one bit of information is a universal constant". But this only works for a photon of wavelength=R. Does this mean that the only information you can add to a black hole is photons of wavelength=R or is this a misstatement? Also, if the mass of a black hole is proportional to its SA, and thus all its energy is distributed over its surface, then even in classical mechanics there shouldn't be an inside of the black hole. If there is an inside, its energy would fall into its center, and its radius would be described by its volume and not its surface area. Even though time stops at the event horizon, energy would still be able to contain the volume if this were the case just as a photon does not experience time but moves to an outside observer. So how can there be an inside to the black hole, if its space/mass end at the event horizon?
Minute 15:17, why did he write time equals to infinite (or approaching in infinity) in the null path of light. On the contrary, time and distance is zero in null paths (dS^2 = 0), because of time dilation and length contraction.
A black hole is the manifestation of quantum mechanics on a large scale. It's the only quantum object in the Universe whose existence can be measured in miles.
nakedshadows He is one of the founding Fathers of String Theory but Cosmology is about Origins: Loop Quantum Gravity and String Theory are the leading Contenders for the TOE and origins of the Universe!!
A bit of both i am assuming. I knew some of the equations and by other relationships, the other equations can be formed. I doubt that he did it on the spot (algebraically), I mean he is teaching this and must have worked with those equations religiously haha.
ILiveuDertHeBrige In academics, clothes, hair, even your socks don't matter. Our biology department head wore tie-dye all the time. He looked exactly like John Lennon with more hair, and he was also good friends with the Japanese royal family. He dressed up when they came to visit; in tie-dye.
32:25 The obvious contradiction to the paradox is that the moment something falls unto the infinitely thin sedimentary "shell" the radius of the event horizon will also increase. Thus never radiating anything since no radiation can escape the event horizon from the inside which is now closer to the observer than the matter which caused the event horizon to expand. I think there is probably no space-time inside the black hole. Or maybe there is just an additive sculpture of some sort of crystallised energy showing more or less where everything that ever fell in joined the existing "structure". But anyway... Happy New Year!
@@miguelfelipedias lol I would never say that. I just said what came to mind when I thought about what was said in the video. Also if something is condensed as much as they are saying (on the way to the event horizon) then why wouldn't it just form a singularity of it's own and simply merge with the larger black hole the moment the event horizons touch? I personally feel that event horizons cannot be warped and that the moment two touch the singularities will simply merge since there is no actual meaningful time or space within an event horizon. Merge into a single event horizon directly at the centre of mass between two black holes. Undoubtedly causing ripples in spacetime from the sudden displacement, but yeah.
superstringcheese in his other lectures the fool with the camera pans the entire freaking time. You'd think at Stanford they'd have someone that knows how to film
I love how in the comments we talk about anything but what the video was about, haha! Look at that guy's sandwich, casual wear, love that guy in the corner studying his lunch box..! lol
+JediMasterOW I watched this bird eating a piece of bread the other day. It was wholemeal bread, not normal white bread. Wholemeal bread is almost $5 a loaf at the moment. Clearly the fluctuations of the price of petrol are annoying. I ride a motorcycle, it has two cylinders. One day I would like to buy one that has four cylinders, not because I will go faster, on the contrary increasing engine mass you reach a point of diminishing returns from the weight. Squares have four corners. I am currently wearing two pairs of socks because it is winter here.
>Squares have four corners. I am currently wearing two pairs of socks because it is winter here. Earth Has 4 Days In Same 24 Hrs., 1 Day God Was Wrong. Einstein Was ONEist Brain. Try My Belly-Button Logic.
it's amazing to me that people who think and work on this stuff daily have the ability to function at this level lollike where they are some how integrated into society to point where they are useful to themselves and others around them quite incredible really
A is in Counterspace. B and R are in Space. The connecting/entanglement of B and R is caused by the Inertial plane. That connects every hyperboloid, vortex and torus in Space. Entanglement between A and B is different. Because energy is opposite in Counterspace, the higher energy shell is against the nucleus. Space, Sigma Inertial plane. Counterspace, Pi Inertial plane. Every Inertial plane has a coaxial circuit. Seems like even blackholes (Counterspacial Sinks) have coaxial circuits.
For some reason, i feel like not only is he one of the most intelligent physicists alive (like top 20), but he may be the top 5 best speakers in physics, excruciatingly self aware and competent with exchanging ideas.
Lol! Physics is not about looking cool as much as it is about being clever! As long as you look smart and smell nice and understand the subject of physics, you are ok.
I watched the whole thing and It was awesome! It's also very mind boggling that these things actually exist... A hole, or a brick wall in reality itself! Sounds magical and intriguing... Reality seems to be far weirder than any science fiction writer could ever imagine!
As a rather ordinary human, I find myself fascinated by both the topic and the virtuosity of Prof. Susskind and the sandwich of the guy in the front row on the right. Makes me hungry.
The definition of asymptotic is a line that approaches a curve but never touches. A curve and a line that get closer but do not intersect are examples of a curve and a line that are asymptotic to each other.
nope that's wrong...entropy formula doesn't consist of any of the constant containing "pi" which is needed if you want to express the surface area of the event horizon... so yeah, it can't be directly calculated using calculus also it's entropy 'S' we didn't need the area for generating entropy since it's constant (as h-cross, c, G are all constants)
Im probably missing something here but if the temp of a black hole is .00000001 degrees and space itself has a temp of 2.7 degrees then thermal energy is constantly flowing into a black hole thus negating , by a wide margin, any hawking radiation flowing out. That being the case, how can it be said that a black hole can evaporate?
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
You know you're a boss when you can rock a lecture off the top of your head in gym shorts.
@Joint StrainI think the point is that this guy could whip out a lecture wherever and get his teach on...I respect that
Robert Curran ....to a group of Astrophysicists, and other scientists 😂👍
Crack
HEY! The man knows comfort, and practicality. It is unnecessary and inefficient for him to wear a suit and tie for what, to stand in front of a chalkboard and talk to a bunch of college students? IMHO it would be fine if he walked into class wearing a goddamn bathrobe and shower sandals.
yo name cum ??????? ;))))))
Casual Friday To do list:
1. Do some laundry
2. Get the Groceries
3. Walk the dog
4. Jogg
5. Give a lecture on Quantum Physics
6. Grab a cold one with the Bois
Best 1 yet
Dream
😂
@@smmascale1785yes
Whit the bois xD😂
I don't know how this guy manages his time between being a hitman for Walter White and giving these lectures
LeadingWay Epic
Brilliant
He treads c
Hitman??? explain...
He looks, and sounds, a great deal like Mike Ehrmantraut from the tv show "Breaking Bad" and "Better Call Saul." It's amusing to imagine a world class physicist moonlighting as a bodyguard.
This guy Leonard explains physics better than most people I've found on the entire internet. Thanks for taking the time for the impromptu lecture. Seriously better than most planned and scripted videos I've found on black holes and quantum physics
Elaborate 🤔!
Did I search this? No
Did I watch it?
Yes
Did I enjoy it?
*_Definitely_*
I am very flattered that you-tube recommended me to watch it, makes me feel smart.
Did you understand it?
@@JuankQuinteroMejia yes & no
I didn’t understand even 10% but still watched the entire video
@@ecmpinky7772 same here
When you gotta teach quantum theory at 6 but dunk on Daquan at 8.
when youre passionate about coaching your kids soccer team but you need some real income
Lmao
lolololol
lol
this comment deserves an award of some kind
Hundreds of thousands of guys listening to what a guy with shorts and slippers have to say and he´s not a football player.
This is what respect should mean.
Hundreds of thousands. That is really great. Didn't strike me until you mentioned it.
Because of the audience do not respect him by eating during the lecture, that's why he can afford to yourself lecturing wearing that funny shorts and slippers. The country in which nobody respects each other
If you're going to criticise the man, criticise what he says not what is is wearing. That is so shallow. He is obviously a lot smarter than you.
+hydrologist86 or maybe just a casual environment? sounds like your country is full of fucking squares
wait i just kinda proved your point 😂😂 i guess with a username like mine i've kinda lost before i've started there
These are the kinds of videos you only watch after midnight when you should be sleeping..
MotoCzar bro it’s 2 am, this comment hits hard
...if you are an idiot
Because we are all trapped in the thin layer
Did you see Joe Polchinski here
like im doing right now 🤦
I'm gonna admit it, I am touched by this presentation. This is the very beauty of the human race. Intelligent people working together to understand the world they live in. keep learning!
The cameraman is moving the camera by throwing batarangs at it.
For real tho
its a machine operated camera
Some real Jason Bourne camerawork there
Shush, he was busy taking notes.
😂
You can tell how well a person understands a subject by how easily they can explain it.
If you can't explain it simply to a 7 year old, you don't know the subject matter well enough. --Einstein
@@qpwodkgh2010 that was feynmann
@@qpwodkgh2010 it's quantum mechanics, I don't recommend it to kids also i think feynmann was a great teacher but he also won't be able to explain the mathematics of QM to a 7-year-old kid, unless that kid is a born genius.
Sometimes. Other times people understand something so we’ll but they aren’t great at explaining it in any other terms understandable by others.
A true talent of communicating physics. I could listen to him for hours with interest. This is really good stuff
Computer science graduate here. I had very little info on black-holes and after watching this video i'm pretty confident that i can talk about it. What a great teacher
A black hole exists in computer too, I associate it with finding the gate that gravity will cease to exist when there is no restriction or too much gravity and time gets stretched when gravity oppresses mass into a pinpoint hole that flips the poles, what we know as matter into antimatter. What does it turn into? A mirror image = v^1.
man, what I would give to sit around a table eating lunch and discussing black holes with other people who are interested. thankfully this was recorded
Fantastic Susskind ... One of the greatest theoretical physicists of all time who lectures in shorts and t-shirt .... simply wonderful !!!
God: do not eat from the tree of knowledge
Leonard: so anyway, inside black holes..
The camera man is great! He knows what we want: sudden panning 👊🏼📹
Psysicists can't pan. It's one skill or the other. But not both.
Prof came straight to the class from his morning jog.
Adarsh Raj physicists aren’t the jogging kind.
@@jaykay2218 its a joke
@@sahil3038 yeah ik. Mine was also a joke.
@@jaykay2218 lol r/woosh for me xD
🎯 Key points for quick navigation:
00:05 *🎭 Unprepared Introduction and Audience Composition*
- Susskind humorously acknowledges being unprepared and describes the mixed background of the audience, including biologists and astrophysicists.
- Expresses surprise about the lecture setup, expecting a casual discussion rather than a formal presentation.
01:29 *🧩 Addressing Black Hole Paradoxes and Quantum Gravity*
- Introduces the talk's focus on understanding paradoxes, particularly around quantum gravity and black holes, which have challenged scientific theory for decades.
- Describes paradoxes as potential keys to new scientific insights, especially when theoretical concepts conflict.
04:22 *🌌 Quantum Gravity: A Unique Connection*
- Discusses quantum gravity not as simply “quantizing” gravity but as a deeply interconnected phenomenon where gravity and quantum mechanics cannot be separated.
- Highlights how traditional methods of applying quantum mechanics are ineffective for gravity, signaling the need for new approaches.
05:40 *🕳️ Black Holes as a Natural Test Bed for Quantum Mechanics*
- Emphasizes that black holes provide an ideal setting to observe quantum mechanics and gravity together, as their nature is fundamentally quantum.
- Explains how black holes reveal surprising properties that may help bridge the gap between quantum mechanics and gravitational theories.
08:13 *⏳ Tension Between External and Internal Black Hole Perspectives*
- Describes how time and space behave differently at a black hole’s event horizon, creating a paradox for outside and inside observers.
- An observer outside sees objects slow down near the horizon, while the infalling observer experiences a finite amount of time, illustrating the limits of classical descriptions.
13:03 *🔍 Classical Infinite Information Paradox*
- Explains that classical physics suggests infinite time and infinite information storage near a black hole’s horizon, a puzzling implication for entropy.
- Notes that black holes would theoretically store infinite information if not for the finite entropy principle, a realization credited to physicist Jacob Bekenstein.
15:11 *🧮 Bekenstein’s Argument on Finite Black Hole Entropy*
- Introduces Bekenstein's revolutionary concept that black holes have a finite entropy, proposing that information is limited even at a black hole’s horizon.
- Describes Bekenstein’s thought experiment of adding information bit by bit, ultimately limiting a black hole’s entropy by the horizon’s surface area.
20:02 *🔑 Building a Black Hole Particle by Particle*
- Susskind walks through Bekenstein's process of constructing a black hole from individual particles, each contributing finite information, to illustrate entropy limits.
- Shows that each photon’s entry into the black hole increases the horizon area, creating a calculable relationship between entropy and area.
24:30 *🔍 Quantitative Details of Bekenstein’s Theory*
- Provides the mathematical relationship Bekenstein used to derive black hole entropy, emphasizing that each bit of information increases the black hole's area incrementally.
- Explains how Bekenstein’s calculations refined the understanding of entropy, grounding it as proportional to the horizon area and finite rather than infinite.
26:29 *🔑 Finite Limits on Black Hole Entropy*
- Bekenstein’s discovery that black holes have finite entropy, later supported by Hawking’s work, introduced the concept that entropy is proportional to the black hole’s area rather than its volume.
- The relationship between entropy and temperature was also defined, with temperature inversely related to black hole mass, a unique quantum effect.
31:03 *🌐 Black Hole Structure and Entropy Observations*
- Describes the “stretched horizon,” or thin shell where entropy appears stored, suggesting black holes as hollow spheres with temperature depending on proximity to the horizon.
- Entropy being proportional to the area rather than the volume implies limited “interior” content, leading to questions about reconciling inside-outside perspectives.
34:55 *🌀 The Holographic Principle and Black Hole Interior Representation*
- Introduces the holographic principle, theorizing that black hole information on the exterior could represent or “encode” the interior, likened to a hologram.
- This theory proposes that information on the event horizon could correspond to internal elements, encapsulating the black hole in a boundary structure.
37:19 *🌡️ Evaporation and Quantum Dilemmas of Black Holes*
- Explores how a black hole’s radiation during evaporation complicates entanglement relationships between interior and exterior regions.
- As radiation escapes, distant radiation becomes entangled with the black hole’s interior, violating quantum mechanics’ principle of “monogamy of entanglement.”
42:16 *🔥 Firewall Theory and Entanglement Conflicts*
- Firewall theory suggests that entanglement disruption between black hole interior and radiation creates a “dead end” for infalling matter, questioning the existence of an actual interior.
- Though debated, some researchers, including Susskind, see the firewall as overly simplistic, implying more profound mysteries about quantum-gravitational connections.
47:00 *🔍 Quantum Entanglement as a Core Principle in Physics*
- Quantum entanglement’s complexity lies in the paradox of knowing everything about a system but nothing about its parts, a notion Einstein found troubling.
- Now integral across various fields, entanglement is central in black hole physics and other domains, marking an “infection” of ideas that continues to reshape theoretical physics.
54:18 *🔥 Firewall Theory and Entanglement Disruption*
- Breaking entanglement between two entities, A and B, near a black hole’s horizon requires energy, which could lead to a “firewall” effect-intense radiation at the boundary that disrupts the vacuum structure.
- Quantum mechanics complicates this as disentangling may force the vacuum state to heat up, potentially altering how we view horizons and event boundaries.
56:09 *🌌 Information Flow and the Black Hole’s Expanding Horizon*
- As information (like photons) enters a black hole, its horizon expands slightly, absorbing new information into its “stretched horizon.”
- This process aligns with the holographic principle, where exterior information is encoded on a boundary rather than passing fully into the black hole interior.
59:11 *💫 Entanglement Persistence and Holographic Analogy*
- Discusses the persistence of entanglement when one of a particle pair enters a black hole, likening it to image charges in a mirror.
- Entanglement remains, possibly with the black hole’s stretched horizon or an interior holographic image.
01:00:35 *🌠 Impact of Black Hole Size on Interior Analysis*
- For large black holes, such as those in galaxies, the central singularity is less impactful on the region near the horizon.
- This allows scientists to study black hole boundaries independently of singularities, focusing on accessible areas near the event horizon.
01:03:05 *⚛️ Hawking Radiation and Quantum Entanglement*
- Hawking radiation, mostly photons and gravitons, could hypothetically carry black hole information outward, sparking debates over whether reintroducing this radiation affects the black hole.
- Entanglement with the outgoing radiation complicates how information and entropy are balanced, highlighting the paradox of reconciling entanglement on both horizons.
01:06:03 *🌀 Quantum No-Cloning Theorem and Information Identity*
- Black hole physics challenges the “no-cloning theorem,” which states identical quantum states cannot be replicated.
- Proposed theories suggest relationships between internal black hole structures and distant radiation, but exact identity between information zones (like A and B) isn’t possible without breaching this principle.
01:07:26 *🌊 Analogy of Dumb Holes and Black Hole Sound Models*
- The “dumb hole” analogy uses sound in a fluid as a proxy for black hole behavior, though it fails to fully replicate information retention.
- While this analogy provides a conceptual look into black holes, it lacks the complexity of true holographic and entanglement features.
01:08:37 *🧩 Partial Entanglement as a Proposed Solution*
- Partial entanglement (where entities are only partly connected) doesn’t fully resolve the paradox since black holes demand maximal entanglement between zones near the horizon.
- This partial connection model introduces gradations in entanglement but remains insufficient for practical black hole theories that assume total or maximal entanglement.
Made with HARPA AI
Photon sphere is the stretched horizon around the black hole, and if you take the circumference of the photon sphere multiplied to Boltzmann’s constant divided into h*c, it will give the photon temperature. Photons which have this wavelength that equals to the circumference of an object are what I like to call winding or circumferential photons.Try taking the momentum of a photon which has a wavelength equal to the electron circumference divide it into the electron mass multiplied to c it will give the fine structure constant. Divide the electron circumference by alpha, you will derive the electron Compton wavelength. In my opinion this is why the fine structure constant exists because it was necessary in decreasing the wavelengths of high energy photons to help them undergo photon pair production from energy into matter.
_THIS_ is a perfect example of pure confidence from someone who without a doubt knows their sh!t: Totally underdressed yet doesn't give a damn what anyone thinks about it and ALSO being able to "wing" an hour+ talk after being given two days prior notice on what is a barely comprehensible subject. We should ALL strive to achieve something in our own lives that at least RESEMBLES what is seen here.
I love your enthusiasm. And I wish I shared it . . . in my opinion, this style of presentation falls way short of earning your level of admiration--though I totally agree he knows his field. If you have time, try a "Cool Worlds" video from David Kipping, of Columbia's astronomy dept. He is my dream professor. I'd very much respect your impression. This is one of his best videos--
He talks highly of Einstein and by that he is bias because he doesn't show the experiment, so I too agree what really can he prove other he can explain.
Very interesting lecture, and intelligible to anyone who has a basic understanding of physics and cosmology. Susskind is brilliant.
I've watched this lecture, at least, 12 times. The way Leonard Susskind, succinctly, connects information into a cohesive idea is beyond incredible.
I actually learned things from this. One of the few presentations which was at an educated layperson level!
Very interesting lecture, wonder how much progress has been made since this lecture
i know some of these words
That's the way they want it .... TyrantTitan .... It is bullshit, don't believe any of it
@@chazzlucas63952+2 is gonna be 4 whether you believe it or not
@@chazzlucas6395 I don't understand it, therefore it must be bullshit. LOL. Way to go through life.
TyrantTitan. Be honest, you were looking for Darkthrone and accidentally found this lecture about black holes.
chazz Lucas it’s not bullshit, it’s a very hard topic to grasp, they are trying to simplify it the best they can. If you don’t understand then I suggest to go look at some basic physics lessons and improve, this is way too complicated to understand for you right now.
Touch the camera again. I swear to god. I'll take it away from you and lock it in my car, Steve.
ha ha ha ha ha
I really got distracted by the guy on the front row, with a sub in his hand and a black hole in his stomach
Seems like someone could've dumped a bucket of ice water on the creep.
How about the guy not wearing shoes wiggling his feet.
21 min
@@thenrepeat9124 Can the guy not eat his sub without being called a creep?
@@thenrepeat9124Imagine letting those sexually deviant sandwich-eaters... near our schools! THINK OF THE CHILDREN!!
This has got to be the greatest lunch TV I have ever seen!!!
Thanks for coming in Leonard
I sure like Leonard. A very nice person. Fun to learn from.
16:10 Here we’re trying to understand acceleration; we have a funny situation ...
that requires meditation; or we’d suffer constipation.
Susskind, the treasure of a nation; most others mere regurgitation.
Front row sandwich fidget frustration; Breaking Bad hit-man confrontation. Ocean and body acidification; steady camera congratulation.
Bit Finesse
Massive time dialation, constant conceptual preoccupation;
Yet consumed we are by the TV stations.
SpaceX and hopeful inclination to space exploration; seems we are a dying nation.
Stumbling upon Susskin is quite the revelation, when you become aware of your station in the equation. The temptation to revel in security of false salvation is one to be reckoned with, not taken for a fools paplation.
@@DylanZapf-dm4mh Bit Finesse this is a very interesting semantic exploration
of your superb creative imagination
rising from my deep slumber of mindless procrastination,
i am writing you this note of appreciation
but please forgive my excessive dramatization
as i present this note as a compensation
for my lack in literary education
@@tusharpandey6584Orange, door hinge. *drops mic*
Brilliant ! Leonard Susskind is making me understand stuff I wasn't even aware of.
In less than 5 minutes, you learned 90% of the people commenting were not listening to the video.
I did keep scrolling up and down waiting for the chalk to start going onto the board and noticed that. Its a mixture of smart and dumb comments. I did notice that the guy wearing the sandals took them off at some point around the 20:00 mark... haha
My god Your right.
Well it's hard to hear, the audio was recorded on a deaf potato obviously.
I was and it is all a bunch of fabricated lies.... Gravity, Relativity and everything claimed by "Science" over the last 200 years is 99% bullshit..... Wake up and do your own research
chazz Lucas hahahahahahahahahaha
I have several books from Leonard Susskind, amazing phycisist
Ya know this dude is the big daddy when he strolls into to give a lecture on black hole mathematics having done no preperation.
This man seems to also be a gifted teacher. In the utmost respect.
I barely got 10/20 to pass high school algebra, and here i am listening about black holes and quantum stuff
Me too
I understood a lot of the words but very few sentences in this lecture. 10/10 would watch again.
I have watched a bunch of Susskind lectures. I thought I had gotten to the end of his points with the holographic /black hole angle. Now he brings in an entirely new physics. Just amazing. And very easy to listen to, in the Feynman model.
I could listen to Susskind forever. He's brilliant. Anyone who held court with Feynman is a hero of mine. Feynman liked him too. His Stanford UA-cam series are fantastic!
watch them all the time trying to get a handle on the maths of classical mechanics lol
koldfushen Seriously? Please cite a reference.
koldfushen I repeat - cite a reference. That's the way science works right? Otherwise shut up ;-)
koldfushen Well I'm a scientist too. Please leave Richard out of this discussion if you cannot back up your claim. Richard would want it that way. You know I'm right ;-)
koldfushen Okay - I'll miss you...
"I dont really know what I'm doing here"
Yeah, Welcome to the club, pal!
40:18 interesting. so you could probe the interior of black holes with quantum entanglement? but more importantly does that mean that if the observable universe was the interior of a black hole, then we could probe the exterior.
I only stopped by to watch for a minute, got hooked, what a great explainer of some crazy physics.
These days, I have trouble getting to sleep, so I've made a habit of watching this video before going to bed , and it helps me a lot.
2:12 legend has it he is still trying to turn that page.
probably stuck on pause.
hahahaha this comment made me die! underrated !
I enjoyed listening to this while doing other stuff. It was similar to my college experience in so much as my brain was elsewhere while smart people talked.
He isnt the best teacher. Like most colleges, they hire super smart people who know their shit, but unfortunately a lot of them are poor at communicating complex concepts.
@@Scorch428 I disagree! I have watched a couple hours of UA-cam (shorter intro videos on string theory, entanglement, black holes, etc) and i obviously don't know as much as him, but i consider him very interesting and actually a *great* lecturer. Especially considering that this appears to be a special topics one-off lecture, not a course. It serves to give a primer in 1 hour and pique interest in the subject.
i know little to nothing about physics yet i'm watching this at 4am
2am for me
Reading and replying to your comment at 4:00 am.
2:09 am
2:36
Landon Ton 9:45 pm
Question: if nothing ever seems to fall into a black hole as viewed from the outside 11:00 then the black hole is never observed to grow. Stuff falling in should increase the event horizon radius, but only *after* it passes the horizon right? Is that a problem or am I just confused?
What a brilliant man teaching a brilliant lesson
as a layman, he made it very easy to understand. the mark of a strong professor
S is used in entropy I believe for "state of the System"
Oh nice, didn't know that
It seems that He got out of bed, grabbed a cup of coffee, and went directly to the classroom !!! :)
maybe someone can help me on this: by 26 minutes we did this: Schwarzschild Radius R = 2MG/c^2, The change in mass from a photon with wavelength=R is noted by M=h/Rc, plug into the Schwarzschild radius to see change in radius --> RR'=2Gh/c^3., which is equal also to its change in the area of the black hole, A. Then Susskind says that based on this, "the change in the area of a black hole due to one bit of information is a universal constant". But this only works for a photon of wavelength=R. Does this mean that the only information you can add to a black hole is photons of wavelength=R or is this a misstatement?
Also, if the mass of a black hole is proportional to its SA, and thus all its energy is distributed over its surface, then even in classical mechanics there shouldn't be an inside of the black hole. If there is an inside, its energy would fall into its center, and its radius would be described by its volume and not its surface area. Even though time stops at the event horizon, energy would still be able to contain the volume if this were the case just as a photon does not experience time but moves to an outside observer. So how can there be an inside to the black hole, if its space/mass end at the event horizon?
Minute 15:17, why did he write time equals to infinite (or approaching in infinity) in the null path of light. On the contrary, time and distance is zero in null paths (dS^2 = 0), because of time dilation and length contraction.
I love how he's doing a lecture like this.. In shorts.
Thank you for the video upload.
A black hole is the manifestation of quantum mechanics on a large scale. It's the only quantum object in the Universe whose existence can be measured in miles.
What a boss. I wish I had taken his lectures when I was at Stanford.
One of the world's greatest Cosmologists and Teachers!!
Colin Dowson I thought he was a string theorist?
nakedshadows
He is one of the founding Fathers of String Theory but Cosmology is about Origins: Loop Quantum Gravity and String Theory are the leading Contenders for the TOE and origins of the Universe!!
Wow. This is what I must look and sound like to my kids.
We should be so lucky.
xD
Was that Sean Carroll's voice I hear answering some questions near the end there? Same voice also said B ~ at 1:03:35
+Ntnher Doesn't sound like him to me.
That certainly does sound like Sean.
This is just intolerable to find someone destroying a mac cheese burger while you are dealing with black holes
This was awesome. Thank you so much for the upload.
I think Dr Susskind is the bomb. He can take complex Physics and explain it to a child mind like mine.
21:34 - 23:50 How does he get these equations? Is he just solving for them algebraically or is he using prior knowledge?
A bit of both i am assuming. I knew some of the equations and by other relationships, the other equations can be formed. I doubt that he did it on the spot (algebraically), I mean he is teaching this and must have worked with those equations religiously haha.
That’s actually the Schwarzschild Radius. It is the bare minimum compression of something with mass for it to become a blackhole.
@@howarddelosreyes463 I meant more so the equations for the change in the energy, mass, radius
@@GhostkillerPlaysMC he is calculating the differentials in his mind.
"Number one, I'm unprepared."
Me (looking at his shorts): No shit, Sherlock.
Lenny always wears shorts and black t-shirt.
Because everyone knows that a proper understanding of black holes requires a nice pair of slacks.
IF you where a proff, you could wear what ever you like. It's the brains not the suit that make the man in physics.
ILiveuDertHeBrige In academics, clothes, hair, even your socks don't matter. Our biology department head wore tie-dye all the time. He looked exactly like John Lennon with more hair, and he was also good friends with the Japanese royal family. He dressed up when they came to visit; in tie-dye.
mrspidey80 clearly he doesn't skip leg day
14:00 We love you too, Dr Susskind - XO
*Thaaank you for uploading this!* Awesome video! 😊🙌🤩
32:25 The obvious contradiction to the paradox is that the moment something falls unto the infinitely thin sedimentary "shell" the radius of the event horizon will also increase. Thus never radiating anything since no radiation can escape the event horizon from the inside which is now closer to the observer than the matter which caused the event horizon to expand.
I think there is probably no space-time inside the black hole. Or maybe there is just an additive sculpture of some sort of crystallised energy showing more or less where everything that ever fell in joined the existing "structure". But anyway... Happy New Year!
good point, but then you think Hawking was wrong?
@@miguelfelipedias lol I would never say that. I just said what came to mind when I thought about what was said in the video. Also if something is condensed as much as they are saying (on the way to the event horizon) then why wouldn't it just form a singularity of it's own and simply merge with the larger black hole the moment the event horizons touch? I personally feel that event horizons cannot be warped and that the moment two touch the singularities will simply merge since there is no actual meaningful time or space within an event horizon. Merge into a single event horizon directly at the centre of mass between two black holes. Undoubtedly causing ripples in spacetime from the sudden displacement, but yeah.
Oh my god man leave the damn camera alone.
superstringcheese in his other lectures the fool with the camera pans the entire freaking time. You'd think at Stanford they'd have someone that knows how to film
It was sooooooo annoying!
The lecture was great though :)
bill gates lookalike in the audience?
superstringcheese I agree. What is wrong with the camera man/woman/transperson/xi/zheir?
Perhaps immortality is living on the edge of a black hole
there is easier ways to go about that but yeah maybe
If only single particles were sentient, lol.
You would only be immortal to an outside observer. You would experience the passage of time as normal
I love how in the comments we talk about anything but what the video was about, haha! Look at that guy's sandwich, casual wear, love that guy in the corner studying his lunch box..! lol
+JediMasterOW I watched this bird eating a piece of bread the other day. It was wholemeal bread, not normal white bread. Wholemeal bread is almost $5 a loaf at the moment. Clearly the fluctuations of the price of petrol are annoying. I ride a motorcycle, it has two cylinders. One day I would like to buy one that has four cylinders, not because I will go faster, on the contrary increasing engine mass you reach a point of diminishing returns from the weight. Squares have four corners. I am currently wearing two pairs of socks because it is winter here.
Must reflect what the new Generations care about. Judging everything instead of paying attention to what's important
>Squares have four corners. I am currently wearing two pairs of socks because it is winter here.
Earth Has 4 Days In Same 24 Hrs., 1 Day God Was Wrong. Einstein Was ONEist Brain. Try My Belly-Button Logic.
JediMasterOW because UA-cam is filled with morons
I like how he actually has a black board.
I remember watching this a while back, and taking notes on it. Very great lecture
Such a beautiful video. Full of light in many ways!
"Here's to pure Mathematics! May it never be of any use to anyone!!"
God I love this guy
The father of string theory is bad ass!
it's amazing to me that people who think and work on this stuff daily have the ability to function at this level lollike where they are some how integrated into society to point where they are useful to themselves and others around them quite incredible really
Brilliant intro into the fascinating topic!! Thank you!!!
Leonard is like yoda of the science world
Wise, smart, awesome and old
Lol this dude's lectures always seem so unrehearsed.. still good
He will get someday the Nobel price for his String Theory
Did professor Walter Lewin decide to draw a couple of lines on the board just before he left the lecture at 1:05:45
A is in Counterspace. B and R are in Space. The connecting/entanglement of B and R is caused by the Inertial plane. That connects every hyperboloid, vortex and torus in Space. Entanglement between A and B is different. Because energy is opposite in Counterspace, the higher energy shell is against the nucleus. Space, Sigma Inertial plane. Counterspace, Pi Inertial plane.
Every Inertial plane has a coaxial circuit. Seems like even blackholes (Counterspacial Sinks) have coaxial circuits.
I hope I am as cool as Professor Susskind when i become a physicist. Look at that cool beard.
+TheGamingg33k
Hi dress sense is a bit lame though, the beard works though.
For some reason, i feel like not only is he one of the most intelligent physicists alive (like top 20), but he may be the top 5 best speakers in physics, excruciatingly self aware and competent with exchanging ideas.
Lol! Physics is not about looking cool as much as it is about being clever! As long as you look smart and smell nice and understand the subject of physics, you are ok.
mjlv Excruciatingly self aware?
His wife will have been happy that instead of coming home he stayed there in this outfit. :-)
I watched the whole thing and It was awesome!
It's also very mind boggling that these things actually exist... A hole, or a brick wall in reality itself! Sounds magical and intriguing... Reality seems to be far weirder than any science fiction writer could ever imagine!
for a complete look, he should be wearing crocks
As a rather ordinary human, I find myself fascinated by both the topic and the virtuosity of Prof. Susskind and the sandwich of the guy in the front row on the right. Makes me hungry.
The definition of asymptotic is a line that approaches a curve but never touches. A curve and a line that get closer but do not intersect are examples of a curve and a line that are asymptotic to each other.
It was either this or “how to build a perfect chest at home”
For your second option, watch your neighbors daughter grow up. Or not.
Both useless for me.
Building a sixpack.
He is like the Tom Platz of abs.
Get him on JRE!
My first time seeing a physics instructor in shorts. He must work out, lol.
This dude is fire. He doesn't care showing up in short. He is killing it. Knowledge is power. He is a cool dude...😀😉😜
Leonard is a genius. Could listen for hours
Result : even the greatest Genius hasn't got the slightest clue what's happening inside of a black hole... 🌚
This is making me hungry
I'm hungry, but it's only partially related to the video.
facepalm this comment reminded me of my food in front of me
dA = d(R^2) = 2RdR, this how you get the 4, no need for Hawking very sophisticated argument.
nope that's wrong...entropy formula doesn't consist of any of the constant containing "pi" which is needed if you want to express the surface area of the event horizon...
so yeah, it can't be directly calculated using calculus
also it's entropy 'S' we didn't need the area for generating entropy since it's constant (as h-cross, c, G are all constants)
The slow approach never quite getting there is like one of those bad dreams
Im probably missing something here but if the temp of a black hole is .00000001 degrees and space itself has a temp of 2.7 degrees then thermal energy is constantly flowing into a black hole thus negating , by a wide margin, any hawking radiation flowing out. That being the case, how can it be said that a black hole can evaporate?