Leonard Susskind on Richard Feynman, the Holographic Principle, and Unanswered Questions in Physics
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- Опубликовано: 2 май 2024
- Leonard Susskind is a professor of theoretical physics at Stanford University and he’s regarded as one of the fathers of string theory. en.wikipedia.org/wiki/Leonard...
He’s written several books including:
- The Black Hole War www.amazon.com/gp/product/031...
- The Cosmic Landscape www.amazon.com/Cosmic-Landsca...
- The Theoretical Minimum series www.amazon.com/Theoretical-Mi...
He also has over 100 lectures on RUclips • Playlist
The YC podcast is hosted by Craig Cannon / craigcannon
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Topics
0:00 - Being perceived as an outsider physicist
4:00 - The perils of becoming too mainstream
5:45 - Where his ideas come from
7:00 - Claudio asks - Do you think the graviton can be experimentally found?
9:45 - The origins of String Theory
15:15 - Why should there be a grand unified theory?
16:30 - Quantum mechanics and gravity
19:50 - Large unanswered questions in physics
27:30 - Holographic principle
38:00 - Simulation hypothesis
40:15 - Richard Feynman on philosophy
42:00 - Feynman and the bomb
46:00 - Improving the world by discovering what the world is
49:00 - ER and EPR - Black holes and entanglement
56:00 - Noah Hammer asks - Could quantum teleportation be used in the future as a means of intergalactic communication?
58:00 - rokkodigi asks - How do you think quantum theory will shape technology in the future?
1:01:30 - Why teach physics for the public? 
Наука
As a 71 year old plumber, I really loved this interview...
His dad was a plumber
Maybe the universe is a giant septic tank?
You just never know what brilliant minds lie behind the eyes of a tradesman. I have learned a lot from folks that can’t spell to save their life but are absolute geniuses in life. Cheers
Lennt is my favorite plumber/physist
@@peggysmith9895 mine also
Are we going to ignore the fact that this man, despite being almost 80, has an unbelievably beautiful voice?
Yes, I noticed this immediately.
And very energetic.
So pleasant.....
The epitome of the wise old man. Love this guy.
deep breathing contributes to having a richer voice AND a better brain. Every voice teacher and neurologists says so. (from meigs, not richard.)
What prof. Sisskind has that other equally great physicists do not possess is the skill of verbal communication. It is a rare skill in that field, a rare gift for a physicist.
Good for you Leonard - stopping the interviewer and setting the record straight. I am sick of interviewers who put their spin on things, paint false pictures and control/dominate the interview. And you did it with grace I think.
Always a pleasure to hear this man speaking, it's soothing. He shows a such intellectual honesty, too little ego for someone with that amount of knowledge .
Watch his lectures, here on youtube and he always has some anecdotes about hopeless students, just to give you some of that humbleness too.
@Enter the Braggn' So you don't think General relativity is right and and gravity is something else than bending Space time?
@Enter the Braggn' I will watch this lecture and get back shortly!
@Enter the Braggn' I'll take this point by point as this is an hour long lecture:
The paradox in particle physics Wallace Thorn hill mentions in the start of his lecture, is real. The problem is that when you try to add together the probabilities of particle interactions in classical particle physics you get infinities and any attempt to deduct outcomes becomes meaningless. This has puzzled particle physics for a century. However with Quantum field theory, there is a workaround as it assumes that the quantum field has limits to its energy levels so the possible number of interactions becomes finite. This solves a lot of problems and is gaining terrain on General Relativity in explaining causality and entropy. It also fits nicely with quantum information theory and quantum thermodynamics as it is pointing at a reality that possibly entirely can be encoded by entanglement of virtual particles. So this classical road block is no longer considered the end of quantum mechanics, which is was in the 60' and 70'
The Feynman qoute: "There is no model of Gravity today..." is misused by Wallace in this lecture as he says that it is a confession that there is no real explanation for Gravity today. This quote is however from Richard Feynman's book "The character of the physical law" and taken in context, what Feynman is saying is that it is impossible to get an understanding of Gravity as a law without using math or understanding math. So quite the opposite of Wallaces point! Here's the section from the Google version of the book: books.google.dk/books?id=SJNPDgAAQBAJ&pg=PA39&lpg=PA39&dq=the+character+of+the+physical+law+There+is+no+model+for+the+theory+of+gravity+today,+other+than+the+mathematical+form&source=bl&ots=Va6iTPxquq&sig=jLhfCe-QOtxL5VN1uAs3B75CGgU&hl=da&sa=X&ved=2ahUKEwiG96qHmKTfAhWRhKYKHU20CkcQ6AEwB3oECGEQAQ#v=onepage&q=the%20character%20of%20the%20physical%20law%20There%20is%20no%20model%20for%20the%20theory%20of%20gravity%20today%2C%20other%20than%20the%20mathematical%20form&f=false
I think Wallaces point about mathematics being insufficient to get a "real" understanding, that we can understand is a fallacy, because it goes by the assumption that the Universe has to be made in a way that makes intuitively sense to humans, which is unfounded. I think math in physics assures us that whatever observations we make are not interpreted in contradiction with what we already know, which makes it the all important bookkeeping, without which, it would just be a popularity contest on which theory sounds the most appealing!
Higgs: Wallace mixes mass (inertial mass) with gravitational mass! the Higgs Boson is only accredited to inertial mass and leaves Einstein alone not objecting to curving Space time as the source of Gravity. The Higgs Boson is mass carrying virtual particle, it does not exist in our low energy state Universe out in the open but is exchanged as a force, just like the strong nuclear force binding Quarks together in Protons and Neutrons. In a particle accelerator it is possible to kick the Universe hard enough to crystalize out forces as short lived particles, and that was the experiment intended in the LHC. It was not about finding a "Mass particle" every massive objects carry around.
Gravity: Gravity is not considered a force in mainstream physics, even if Wallace claims it does. Stuff falling does not experience a force as they free fall. Newtons second law of motion still applies: "An object stays at rest or stays in linear motion until a force acts upon it" It is space that is "falling" towards objects bending straight trajectories into collision courses with the most massive object around!
E=MC2:
Wallace thinks Einstein says that matter, Mass and the speed of causality (light speed) is the same. I don't know where to start with this: The popular Equation is a shorthand version. The real longer version also accounts for an objects relative motion and thermal energy, which makes the equation perfectly fit with classical physics. Einsteins conclusion is that matter is possibly the same as energy to the Universe and by that makes the physical laws consistent, the speed of light however is the speed of causality, the speed of which things happen which also needs a fixed speed for the books to balance (thing staying in, or out of existence, and the reason you have to supply the energy equivalent of the mass of the chemical bonds in gasoline to your car to make it go)
Vacuum as a medium:
Wallace objects to the notion of "the Aether" as the medium for conducting light was disproved. Einstein did show that it could not be a physical medium light needed, like sound waves, but did not have the science to come up with a better explanation, so he left it there. This has not stopped science however. Quantum mechanics have had a crack at this for a long time and currently Quantum information theory is trying to come up with numbers for how fast entanglement can propagate information. In other words causality is the clock speed the Universe computer is running, so there is an "Aether" still in physics in that sense.
Newton:
There is still a problem in physics with celestial dynamics, as Wallace says, when applying General relativity to calculate orbits, by the fact that if Gravity has a speed the formulas get very complicated in General Relativity. However there is nothing that breaks when super computers crunches 3-5 objects interacting gravitationally. We can't just get any further with current computing power. Also in Quantum dynamics Virtual particle interactions and entanglement happens much faster than the speed of light and is to us instantaneous, so it can very well be that light speed is only constant in this part of the universe we can comprehend as mere mortals, but that is the limit of human brains and lab gear and what we consider the physical universe.
Big G, the gravitational constant on Earth is tied to Mass on Earth by weight because Earth has a fixed size. Physices does not claim that G is an universal constant so this is a straw man argument.
The Ultrasaurus was a fossil discovered in 1979 in Korea and later found out it was a mix of fossils from different dinosaurs. Not a hoax but an error at the dig site. Using a fossil that has been debunked for 40 years as proof that G was lower historically, makes no sense to a physicist!
Sun-Moon-Earth tug of war: I thought initially that Wallace understood Newton, but apparently suggesting that the Moon should be pulled into the sun because it exerts twice the force that earth does, is face palming level. If Wallace could be bothered to take Newtons simple formula for gravity and do the numbers 3 times for the Sun-moon, the Moon-Earth and the Sun-Earth respectively, he would discover that the bodies would stay put exactly where they are supposed to be regardless of the orientation of them.
Suns composition: Is mostly Hydrogen, but why shouldn't it be layered like any other object? The spectrograms of the Sun only shows Hydrogen and Helium, but everybody knows that light is only emitted from these elements so heavier stuff in the centre would not light up (fuse) at the current core temperature the Sun has. This is not a mystery!
I have to stop now, unless this two hour exercise becomes an all Sunday event, but I ask you this. If his argument for the electro magnetic force being fundamental is a 25 minutes of pseudo science introduction, before he even gets to his presumably experimental easily understandable results, He is no better than a flat Earther that says NASA is lying every time provable evidence is presented.
Sorry we never got to black holes, which was my original objection to your statement, if he ever mentions it in this lecture. You can point me to a specific video or section of, if we should discuss this specifically. However, I don't think Wallace is going to put up a credible argument.
Cheers!
@Enter the Braggn' Excellent, he's not worth anybody's time, it is not a case of of an i'll made video with a camera shy nerdy professor , but intentional fraud.
This is one of the best things I've ever seen on RUclips. So glad to see Professor Susskind in a so good shape.
+White Boar, agreed. If you want to see another outstanding series of videos on YT try the playlist before the big bang by YT content provider SkydivePhil.
I think anyone who appreciated this interview will also like that series which includes conversations with such luminaries as Hawkins, Guth, Penrose and many others.
You guys with your hands full of physics books and theories about everything, need to read some poetry before it's too late. But that might mean walking across the campus and remembering when you fell in love for the first time. Oh god, save us from these kind of idiots who listen to Beethoven to find where he went wrong. Talk about black holes.
@@charlesdavis7087 If you can't find poetry in the textbooks or theories, it sounds like your own personal problem.
What's your problem? Never mind. I don't want to hear about it.
78
Great interview. Susskind always makes me feel smarter for having listened to him. A rare quality these days.
andybob unlike the comments
true. i could understand him, so i should be a genius! lol that’s the kind of feeling we get.
The first 15 seconds are legendary. I admire Dr. Susskind for his patience.
Great interview Craig!! Keep up! And yes, you really do not understand something until you can explain it clearly to someone else. Incidentally I think the best way to learn something is imagining your role as a teacher teaching it. Dr. Susskind is a titan
One of the greatest minds of our time, truly enjoyable to hear him speak. Thank you for the interview!
I’m so happy that science and deep thinking is becoming a popular “thing”.
It is not.
Don't kid yourself, how many people do you know in real life that watch these kind of things? I have many many friends and colleagues and I know 2.
@@jesperburns Precisely my thought! Thank you for sharing.
For every person interested in things like this, there is a much larger group interested only in the key concepts and a MUCH larger group who don't care about any of it.
@Fernando Cunha It's the way we live that brings this on; our money ain't worth nothing if the markets don't buy and sell - hence media teaches consumism only, and schools play the role of differentiating people based on their memory capabilities rather than teaching them anything in a meaningful way; Big companies need no geniouses, they have 'em already. They need people able to absorb and reprocess what they're told: biobots, "sheople", call them what you want. In 150 years machines will be able to take over most of the tasks we humans do even in philosophical and theoretical fields - maybe by then people return to knowledge and wisdom. But by now most would call a well educated person a "nerd". You can still buy anything you need atm rite? Haha :)
It's such a bless to live in the modern world where valuable conversations like this can be shared and spread so easily. Thanks!
This man is responsible for string theory, quark confinement and M Theory.
And an excellent lecturer too, in addition to the rare combination of a physicist with a personality and sense of humour.
Always a joy to hear Lenny. Great interview!
he is such a great teacher. His lectures are pure gold. I am glad they are saved for posterity,
Outstanding interview. Very profound answers of one of the top minds of mankind. But that's also thanks to the one asking those questions: very good job! Thanks for this video.
“When you have eliminated the impossible, whatever remains, however improbable, must be the truth.”
Correct.
@@sherlockholmeslives.1605 Was it " The speckled band " ?
@@keybutnolock
I don't know, Keith.
I think not ! The Sign of Four, ch.6 (the wonder of Wiki)...I did check however, in a chat about the "wooden legged man" scaling a a wall.
Now I can sleep : )
Unless there is something else you just haven't thought of...
SOOO many awkward interview moments here...it's a testament to Susskind that he was patient enough to stick it out and help Craig along.
really awkward when this young interviewer said he was radical crazy mad scientist type...leonard has always been a mainstream genius.
Dude literally asked a physicist if he was jealous 🙄
Thank you so much for this. Legendary interview, and you encouraged him to talk about the real deals!
What a great interview. Excellent questions, and a host who listens!
Certainly one of the best, natural and informative interviews I've seen with Dr. Susskind. Truly one of the greats of our time. Thank you!
Thank you for your time and attention to me (the public). Prof. Susskind is one person that I greatly admire and respect in that he has greatly ignited thoughts, concepts and views that have shifted me along my path of life. Again I thank you.
Finally, I had been waiting for a Susskind video this year
1 hour video didnt seem long because of the quality of the content loved to hear both of you talk
Makes me wish I had studied harder every time I listen to Dr. Susskind. A great man.
I love this guy. I love all people that take the time to explain a thing that is hard to understand. There aren't many people like that.
Thank you...thank you so much for this interview...was so happy to see Sussind doing well....hope you do more interviews with physicits...love from India💓💓
This is gold! Great interview my dude. Please invite him back.
Intriguing, informative, enlightening, and absolutely fascinating!
Lenny ... you are our science hero
This is such a great interview. Thank you for this
Agree but for me on a par with Roger Penrose.
Leonard, you truly are an artist in the way you explain these concepts.
Epic Leonard Susskind! Thank you so much!
Nice interview. Lenny makes theoretical physics look so easy.
This interview was superb, to the point. Please interview more scientists and mathematicians.
Great interview! It's not the first time I have enjoyed Professor's Susskind's great art of vulagarisation to fit my own mind, but it was great to get to know this interviewer. Well done!
Brilliant man and outstanding topics!
My favorite living physicist!! (edited) great ending! I feel I know Leonard on a more personal level after this interview!
Beautiful story at the end
GREAT interview, thank you. I would love to see you do a whole series on physics.
Fantastic interview! The most spellbound hour I've ever spent watching a video on RUclips!
Very enjoyable, good questions and good interview.. Great job :)
Thanks for the interview.
Incredibly interesting interview, and brilliantly hosted! Subscribed.
Dr Susskind is one of a kind! He is a modern day genius and it’s so fun to see his mind articulate such deep truths.
all love and respect to leonard susskind..💕💕 and thank you for this interview
I was a fan of Lenny since I got my laptop and U-Tube, 6 years back. As I was watching this video, it occurred to me he is 8 years older than me and may not have much time like me, to charm the magic casement. He is a charm to watch and listen. I will now go and dig the Complexity of ER=EPR.
Susskind is a PhD physics friend from Cornell, who went to Stanford and I also did after graduation.
Even with comparable education, I still watch all his lectures and still learn much from him.
Wonderful educator
One thousand thumbs up. Thank you for this!
Wonderful interview!
Brilliant interview. You asked very cognizant questions. Thank you. Great man.
Thank you doc. You’re a gifted teacher. One of your continuing ed students.( The guy from montana who always assumed you didn’t remember him :)
very exciting. Thank you for asking him going technically. That was the most fun part where it leads to the equation of the wormholes and the entanglement of black holes. Mindblowing.
I wholeheartedly agree! As a former physics student, I do understand it, and it led me to have a crack at reading the ER=EPR paper, absolutely mindblowing stuff. It's not very mathy, so many people should be able to at least get some out of it too, just like in the interview.
It's always great pleasure to hearing L. Susskind.
Excellent interview! I highly recommend Professor Susskind's physics lectures on RUclips. He definitely has a gift for clearly clearly explaining abstract subjects like Quantum Mechanics.
Not to forget he is one of the developers of String Theory!
This man is razor-sharp for being in his late 70s here. Very impressive man, love his voice too.
What an awesome interview of an awesome interviewee, great job! From a big fan of Prof. Susskind 😊
The last 5 minutes rings very true. You learn even more by explaining, and you can often solve an issue too.
I haven't seen any Lenard videos in a couple of years. I explained his holographic principle to a guy in a bar in Amsterdam on saturday. I was drunk and pretty amazed that I was able to explain it so clearly, which is a testament to Leonard, as I learnt from him and the way that he makes it so simple to understand.
I'm NOT a scientist - only a fan - and still I enjoyed this very much. Only the smartest people have the ability to explain something stupendously difficult in an easy matter we all somehow can understand. What a great guy. Thx a lot!!
One of the best scientific interview I have ever seen. The interviewer was great and ask so much deep questions. Great job Sir.
Leonard Susskind is a 21st century wizard.
Great interview!
Leonard Susskind is a world treasure, and a deeply kind, gentle and generous man. All professors should be as wise and capable.
He is such a relatable guy. Enjoyed this interview immensely. At the very end he said something that I have completely experienced; that one learns better while teaching.
Interviewing like this is really appreciable! I like that host sometimes mildly pushing him to dig more technical stuff. After one of the time with battling that they should go more detail or not for not making physics too boring for general audiences, I was kind of saying "who cares? go dig down!" then just host said "If I get drop and some of the listeners have to drop that's okay but certain people like it a lot "
whoever the interviewer is, you're doing a great job keep it up
agreed. great job
Thanks! -Craig
"hmm"
Wow... (No, he's not.)
yes, excellent job!
I am very happy that the RUclips algorithm insisted and kept showing me this video over and over again. I really wanted to watch it, but whenever I checked RUclips, I did not have the time to do so. Until now. I am deeply honored to have had this experience. And I ask what sorts of things lead to this very moment, when I am writing this comment right now. Also ask yoursevelves, why are you reading it... I have so many things I wish to write here, but I will not do so. Let me end just with one statement. I am thankful, humble and sort of honored to have had this experience. Thank you. Best wishes, Erik.
This really made my day bless
There are a handful of individuals throughout human history who have, through reason, intelligence, study, and experimentation, changed and expanded our understanding of the vast universe in which we live. Leonard Susskind is one of them, and I am honored to have lived in the same period of time as this man.
😮, thank you YC and you Craig especially for the coolest podcasts on the web👍😎
Second that ^^
Thanks for checking them out! :) -Craig
I'd give my life's work to boost the confidence and spirit of all these brilliant physicists that I watch and listen to day in and day out just to have a chance at changing the way this goes
Beautiful interview. Thanks!
Really good interview.
I held on for as long as I could and after that I just enjoyed the interaction tuning in and out when I heard a word or concept I am familiar with.
Will be saving to revisit as my mind grows🤗
liked the interview, awesome
Awesome interview. It felt personal and simple to follow.
thank you very much leonard
Great interview. Thanks a lot for this. Prof. Susskind is absolute pleasure to listen to. The questions were also interesting. Please do with more physicists.
I always enjoy the insights presented by Susskind. The Universe and everything with relevant reservations about uncertanties, string theory being one such thing. Yes, fill RUclips with Leonard Susskind!
pure youtube gold here, thank you!
Yay all the Susskind! I always learn something when he talks.
His lectures are legendary -- to the point and unscripted like a master composer.
It's awesome that we still have a few of the minds from that era left in the world.
Amazing how lucid and lively his mind is at such an age.
I always enjoy his lectures, and now I know a little more why I have liked Feynmans as well. They have a style of teaching and a certain flare that brings something so technically advanced to almost understandable. Now if I only understood the mathematics and equations that support classical and theoretical physics.
Absolutely a great mind and I love listening to such an amazing person thank you so much.
One of my most respected and very interesting physicists. Great conversation. Enjoyed every minute. Thank you.
I am so grateful for this opportunity to reconnect with a long time friend I had forgotten unyil I remembered 🙏
15:07
"I don't know what people think. I know what I think." I love that sentence.
This is one of the best interviews I’ve seen on RUclips. And sadly...I watch many lol
Thanks! -Craig
Excellent.
The paradigm debate.
What a great interview.
Thank you for this video! it made my day
This makes me so happy to listen to.
Great physicist and educator!
Thank you for the important interview.
Our living mentor, thank you so much Leo.
Thank you so much.
Susskind I love you😍😚
My favorite "conservative" physics guy! Reminds me of one of my best friend's dad who was a math professor (St. Olaf college) working on string theory... typical eccentric "mad scientist". He was always worked up about some new theory and eager to share it with any passer-by. One of the happy parts of my childhood.
His explanation at 1:02:00 about the value of teaching is the golden nugget in this whole fantastic interview. Someone else described it, "You don't understand something unless you can teach it." Einstein said something similar.
Einstein said if you can't explain it to a child then you don't understand it yourself.