"Today, a young man on acid realized that all matter is merely energy condensed to a slow vibration — that we are all one consciousness experiencing itself subjectively." ... "Here's Tom with the weather"
Don't you know how hard you whacked the electron with the photon? Can't you figure out the electron's velocity before the whack by conservation of momentum?
@zeperf88 No because an electron has an undefined state of momentum at any given time. You can only gather probabilities for different momentum states.
He starts explaining and my mind is perfectly grasping everything, giving me metaphors to get how this works in the real world and suddenly I get to a point I don't understand and my mind goes "Wut" and I just don't understand anymore.
Susskind makes interesting generalizaion: (ab)*=b*a*... this implies non-commutative prop however for a 1-Dim complex a,b this is not true, they do indeed commute and (ab)*=a*b*.
It is not until we generalize complex numbers a,b to a higher dim 3-Dim or greater that we run into non-commutative prop. Let a be a quaternion such that a=1w+ix+jy+kz, over a vector space spanned by basis (1,i,j,k) where i,j,k are complex such that ii=jj=kk=-1 and ijk=-1. Only then (ab)*=b*a*.
@cesarjom He doesn't say that they don't commute. (ab)*=b*a* means that (ab)*=a*b* by commutativity of the complex numbers. Writing it that way doesn't make anything wrong, but it works for later on.
@jamma246 - my only point (and I think I was not very clear about it) is that for higher dimensional complex numbers (eg quaternions having 2 additional imaginary terms), it is not true that (ab)*=a*b* if a,b are quaternions. For same, it is true that (ab)*=b*a*. This result is consistent with the fact that quaternions (eg a = 1w+ix+jy+kz where w,x,y,z are reals) do not commute, b/c in the basis (1,i,j,k) of a quaternion, ij = -ji while ii = -1.
When compared with all the other luminaries, Susskind certainly lags very far behind. This quality is apparent in his writings as well as in his lectures.. In my personal opinion, the reader doesn't get the same feeling of a powerful or brilliant mind, as when w itten by Einstein, Heisenberg, Bohr, Schrodinger, Dirac, Kaku, Lewin, Balakrihnan,Green, and countless others..
I hope to be able to endure his lectures and learn something from him. I also hope the would change my mind.
@nementerc... note that a great theoretician does not neccesarily mean you have a great communicator (ie lecturer) particularly to the layperson. Such is the case of Dr Susskind, his insights into his areas of physics are priceless to graduate-level and follow physicists where he can provide much more detailed mathematical arguements... for the layperson there is not much advantage as Susskind lacks the eloquence and succinctness of say a Richard Feynmann.
why do I need a dual space if I want to define an *inner* product. cant one just stick to either the bra- or ket-space, i.e bra A | bra B or ket A | ket B
And why is
ket A | bra b of more interest than say bra A | bra b ?
@mdinka The inner product is cancellative, degenerate, like multiplication of a vector with a dual vector or complex by its conjugate. bra a bra b, ket a bra b, and ket a ket b are, to my understanding, all outer products.
ket A bra B maps a ket v to ket A bra B|ket v. bra B|ket v is a scalar. Ket A bra B uses bra B to decide how much ket v should scale ket A. When you interpret ket v through bra A, you get a projection operator P = ket A bra A = P^2 = ket A bra A|ket A bra A.
@mdinka ... braA | ketB is just notation (Dirac notation) for the inner product, which is DEFINED as sum (over n) of (An*)(Bn) where An is nth component of vecotr A and note An is a complex number.
... or equivalently ketB is analogous to a column vector A. And braA is the transpose conjugate (*) of the column vector ketA. So in this matrix representation, braA | ketB is the same as our original definition: sum (over n) of (An*)(Bn). It does NOT make sense to write ketA | ketB... that would be like trying to multiply 2 column vectors (dim Nx1). Inner product is a number (scalar), so you must use Dirac notation that is consistent with that result.
QM normally involves very complicated PDE's and easy ODE's; however in an undergraduate course you are given the answers to all the pde's, no real math is invovled - if you want math, don't go to physics. Granted its is interesting to note all the besel functions and field theory that goes into deriving QM.
.... differently too. Now, all this math looks like garbage yet it worked for the atom sized humans. Those atomic humans then try to understand our world which is really really big compared to them. So they take all that garbage math they made that doesn't make any sense to us and try to explain us but in their atomic math language! You see! They can't ! Cause there language is different from ours so they understand it differently and we just can't understand each other.
.... looking at the math from another viewpoint we see a weird world. Maybe the world of the atom ? Just cause the math doesn't make sense doesn't mean it's wrong. Thus, in order to "really" understand we halfto not be human and think that apples can only fall from trees because what if the tree is falling from the apple? Try to think of it this way. If we were the atom then we'd have our own math system with numbers differently, maybe from 1 to only 3.14 then we'd operate on them ...
Now to talk about something interesting. Our math is built around our perception and the answers are accepted when they make sense to our perception. However, because we can't seem to understand things outside of our perception....what if the real math was to be built outside of our perception such as 1+1 = 5.617 ! Then when you build all the imperceptible math at one viewpoint we see our world with all the exact same perceptions that were used to. However....
Notice the f=. I did that on purpose. Even equality or assignment is fuzzy. Think of it this way. If you take one apple from one basket and put it into another basket do you really think that you took the "whole" apple and actually "put" it into another basket? Of course not ! All you did was try to put the apple into the basket, unfortunely it's not the same apple as the apple that was originally in the basket :(
Unfortunately he is grossly wrong about how he constructs the math to respresent the laws of the universe. It's not quite that simple. 1+1 is not really 2. Therefore, the entirety of his lecture has to be scraped and redone from the begining. The actual math is to use something of a fuzzy number like f1 + f1 f= f2 where f is the "fuzziness" of scale. f is both fuzzy in delta time and delta space and delta anything else you can think of. Sorry people, nothing is simple :(
I am a physicist. I havent been doing real physics for a while. For me these are just fond memories. I am quite astonished that none of this has slipped my memory. Susskind is a great lecturer. He really knows how to boil it down to the basic concepts, which are not so difficult. I am quite astonished that he is discussing the abstract hilbert space at considerable length, since these lectures are not directed to professional physicists. But, I like his approach.
@unimoggie Yes, I think it does. We know that alpha h star times alpha h is a positive real. He just stated that probabilities should also be positive reals, so I think it would logically follow that he means the complex conjugate. Also, he hasn't given any other definition of star other than complex conjugation. So why should we assume it has a new meaning.
When he writes P = 'alpha star H' x 'alpha H', does alpha star signify the complex conjugate of alpha star, or something else? I am afraid my maths is very rusty and I may not have followed the lecture perfectly! Thank you :)
@nickharvey7 Nope, the Uncertainty Principle is more fundamental than that, though he hasn't covered it yet. It states that the standard deviation of the momentum superposition times the standard deviation of the position superposition is >= hbar/2. As such, supposing you have an exact known particle position, the particle is in an infinite superposition of all possible momenta at that time. Crunching it through the Schrodinger equation gives a deterministic result for all future times.
@hackulous Yes! but when the superposition collapses it will only have one position in space and time. Could this not be a new moment in time as part of the time continuum? Because classical physics is an approximation of quantum physics is it not possible that Heisenberg Uncertainty Principle is the same uncertainty that the observer will have with any future event?
Could Heisenberg Uncertainty Principle be the same uncertainty that the observer will have with any future event? If time and the geometry of spacetime is continuously being formed by the momentum of EMR or light. There is no understanding of time in modern physics or why we have a future and a past. Could this be why we have the paradoxes of QM?
Why specifically do you say,"There is no understanding of time in modern physics or why we have a future and a past". Are you talking about continuous vs quantized distributions?
@QuaterionEM I specifically say we have no understanding of time in physics because we cannot explain why we have a future and a past. We can look back in time through light years of space at the stars. But when we look down at the atom we only see probability. Could this be because Heisenberg Uncertainty Principle is the same uncertainty we have with any future event?
@nickharvey7 (macroscopic) future as ALL probalities NOT YET measured is still dependant on the notion of time, i.e. not yet determined as in a discreet state by any interaction whatsoever in the NEXT instance of time just because this interaction has not yet happened THIS instant of time. And would this line of thought not do somewhat confuse relativity with QM? - or maybe it's THE Step to the ToE - Supertimesition perhaps? - honestly, me just getting more confused from lecture to lecture ...
@roboflop314159 In this very simple theory creation is a continuous process and the flow of time is formed by the continuous inward absorption and outward emission of light or EMR. The process that forms Heisenberg’s Uncertainty Principle also forms the Arrow of Time!
at the risk of sounding slow. if i follow this correctly; it would seem that it would truly be mathematically impossible to violate the uncertainty principle since there would always be a value associated with you looking at the system.
It's just the definition of the dot product in that space. As the guy is saying it satisfies the necessary requirements of a dot product. Dot products can be defined differently in all different kinds of spaces.
The integral version and vector version satisfy the same rules. You can see in the 57-58mins that he does the dot product for vectors and that produces a sum. An integral is like a sum over an interval. Wavefunctions are infinite dimensional, the vectors aren't.
Why some people insist Susskind should explain "clearly"? QM is not something you can find the analogy from our macroscopic experience. Just get used to it.
""TO ALL PEOPLE WHO ARE READING THIS : DOSE THE ELECTRICITY OF BRAIN CAN BE HACKED VIA SOME TECHNOLOGY? Can ANY Microwaves or ELF Waves Manipulate the Electricity of the brain?
My Clear Question : Do some people Reading OUR MINDS And manipulating our subconscious regions of mind-brain via having the electricity of our brain in thier computers?
What a boring communicator. He may be brilliant and accurate... but his verbal flow is horrible, his train of taught scattered all over the place. Laurence Krauss is more interesting.
Yes, an ingrate like you would like Krauss. Krauss the sniggering hegemonic iconoclast who, like Dawkins, Miller, Hitchens, Myers, has adopted the cynical excuse that the people are too stupid to understand and therefore must be lied to in order for their own good, oh and merely incidentally the aggrandizement of the issuing blind establishment whore. Krauss's bullshit is that he equates quantum fluctuations to 'nothing' so that he can hype his 'universe must arise from nothing' rubbish.
I know girlfriend: what a bummer! There he is describing how to manipulate the awesome fundamental inexplicability of existence in measurable terms and he has the audacity to not even be charismatic and funny and condescending and deceitful! Sheet! You should ask for your money back, and please, do put plenty of plastic sheeting down before you blow your brains out.
Nice one. Put up some identity, then we'd be inclined to give you some cool links depending on what you're into. Welcome anyway, its pretty mad out here, but you can learn a lot if you want to. More than one ever dreamt.
Truly excellent lectures invaluable if you are learning quantum mechanics. The logical next step would be field theory. It would be great if Stanford would provide this as a public service.
If any one can explain this complex topic Prof Susskind can.
I don't think anyone understands a word I write. Physics is kid's stuff. Try understanding human thought while you are human. As for Physics, humans are very advanced compared to other species, but it was not long ago that humans humans didn't know what an atom was. Humans think that Einstein was/is some sort of genius. He simply was not as closed minded as others.
I was KIDDING as in being SARCASTIC. But kindergarden kids do just as important work. The string theory cured no one of anything. It's as clever as many other "ideas" and in the future may well end up as a historical curiosity, just like the "radiator theory" of human evolution.
You were SARCASTICALLY saying that the whole of physics rests on trying to rescue naive realism until you bump into quantum theory? Why? Most people when they are SARCASTIC at least try to say something funny.
It is a mathematical model that fits a number of experimental results. No experiment has ever shown it to be wrong. There are things that QM doesn't explain, though. Would you say that is an explanation for reality?
All kindergarten kids have the same insights in physics... they correlate datasets from 3 senses to extrapolate a 3D world from 2D images and they postulate the existence of an independant objective reality... naive realism.
The whole of physics rest on trying to rescue naive realism until they bump in quantum theory.
Oh, there is movement called "taking children seriously" that might disagree wih you about the capacity for children to make scientific progress.
@acr08807 Yes I believe that we have missed any point within definng QM' this has more to do with how people are not using faculties and are simply being programmed within memorizations' without having any intrinsic fruitions within how the mind actually facilites and uses any kind of knowledge' this is definately a west coast thing' and I want to go to Stanford some day and get a degree for psychology' psychology is what? Dealing with any and all interpretations within any impression?
@DrFruedienslip This has everthing to do with how people can and are being conditioned within any and all charaterisations to any identity; this another part within how capitalism and despotism go hand in hand while lendiing to socialism; which is all based within fear in one way or another' which has everything to do with social separations withn economic degradations though each part supports the whole within any existence'
@acr08807 What Psychology? The one we live in? Does one know what a question mark represents? Postmodernist humanities? What does this mean? Any principles within human human are unchanging is should become any point to QM' Why did Einstien say' God doesnt play dice with the universe? All Im going to say is that construal is what we are referring to when it comes to any mind within reasoning anything within any existential experience' Intrinsic Anthropology' and economics explains despotisms
@acr08807 Oops I messed upo on a couple words' However Intrinsic Anthropolgy is a clue here to a book thats being written' have you ever read Sarum? any world view looks at the past and the present wanting to know what is or isnt predictible' the metaphysical side to quantum mechanics has everything to do within defining human character traits' which is what philosophical statements exemplify' why has there seemingly alwaysbeen the argument over defining God' is god truly a person or Theoretical
And he can still handle it. Usually when "you can't get your thoughts straight", you can do only simple things, like washing dishes, and can't explain relativity or quantum mechanics. And he just can do it that easily. That's the level he's on. Einstein said, if you can't put it simple, you don't understand it well enough.
Btw I think he could get his thoughts straight any time if he would have to.
How many people with no degree discovered more than those WITH a degree? Many! And how many are/were greater experts in their field with no degree? You have all the time you want to research this. The percentage is far greater then you thinkl.
I understand that, but the Degree is important, that is if you want to be hired under your particular field. You will not be hired despite your intelect and research over someone who has a Degree.
Getting a degree is FAR more than casually listening to lectures. The courses themselves demand that you 1) do much supplementary reading 2) work through difficult homework problems and 3) take midterms/finals to pass. Not to mention the countless hours of laboratory work and student research which are required. Merely listening to a lecture, while both fun and informative, is actually a very small portion of the educational experience leading to a degree, which is why employers rarely go for it
J barret = a shady immoral lying conspiracy theorist..
Religion will never win a philosophical debate nor a scientific debate (especially not with Idiots like Kevin J barret , ahmed deedat etc. LOL)
If you wanna believe in fairythales and DONT INTERFERE WITH PEOPLES LIFES AND HUMAN RIGHTS, fine.
Dont expect to be taken seriously when trying to debate on an intelligent base, since all these guys are doing is TRYING TO FIT IN PSEUDO SCIENCE AND HOCUS POCUS to PROVE their god,keep trying HAHA!
heres something interesting about ISLAM and what we muslims know regarding the universe and its physics and paralell dimensions and beings -read article "Quantum Islam" by Dr Kevin J. Barrett also check out Gordon Creighton's essay: The True Nature Of The 'UFO Entities. and you'll soon discover ISLAM'S authority and unlimited knowledge on everything seen and unseen.
J barret = a shady immoral lying conspiracy theorist..
Religion will never win a philosophical debate nor a scientific debate (especially not with Idiots like Kevin J barret , ahmed deedat etc. LOL)
If you wanna believe in fairythales and DONT INTERFERE WITH PEOPLES LIFES AND HUMAN RIGHTS, fine.
Dont expect to be taken seriously when trying to debate on an intelligent base, since all these guys are doing is TRYING TO FIT IN PSEUDO SCIENCE AND HOCUS POCUS to PROVE their god,keep trying HAHA!
So I guess you are here to remind us of how they lived in the middle-ages (-east?). Your narcissism and anger stem from fear. Your fear is of a paranoid type (everyone is "evil") and a result of latent homosexuality, which stems from unresolved love-hate feelings towards your overly-severe father. You hide all of these character *flaws* behind the "veil of Islam", but the truth is you are a coward who projects all his hate onto everyone else but the person who deprived you of a mind of your own
all of the forces are the universe abstracting from the 3D matter the 4-dimensional destruction of it. By holographing properties that we observe from particles, we observed that their activity requires 11 dimensions to describe, but it's all meaningless to us, because in reality it's just the completely incomprehensible barrier necessitated by 3 spacial dimensions.
I like the teaching style but some of the stuff he puts on the board doesn't connect to other things previously discussed...Idk it might just be me...
No offense meant, but what is your background in physics? The first couple of lectures he is leading into vector space discussion. You need a strong base in complex numbers to under stand more advanced vector space ideas such as the "space time cone". (v1 v2 v3 v4)
I am currently majoring in particle physics actually. I'm starting up quantum mechanics this coming semester. I was just voicing my opinion. Sorry. =/
if we consider dimensions in physics as analagous to dimensions in mathmatics. we could assume that time is a fourth dimension and that quantum behavior shows us a hidden 5th dimension within time. the hidden dimension in time is when a quantum movement cannot be reversed because it has been observed.
if we extrapolate from this we see that the 5th dimension is the observer effecting particles moving in 4 dimensions.
But dimensions do not see as we do. They exist and are, for lack of a better term, seen by us as existing in and around and on and under and as eachother. It's hard to visualize but I hope you can understand my thinking. Wait! I think I've got it. Imagine a two-dimensional plane and a point on it. You have that point and it's all good. You add a Z factor to the point and it is now Three dimensional. You add (there's no symbol for time!?!) a fourth value and it becomes possible in our understand-
ing. The fifth dimension must therefor be -- Oh, sorry, reading up on the fifth dimension, I found out that the fifth dimension is the probability dimension in some theories. If that was what you were refering to then you are correct. In a sense. Before I proceed and make a fool of mysself, could you explain in more depth, what you meant to say.
mitten cocks
QM973 1 week ago
niggers
QM973 1 week ago
how can you measure a specific particle if you cannot distinguish between them?
QM973 1 week ago
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simplelife1021 2 weeks ago
stupid comment: your so called blackboard , is actually white. mister quantumphysicist
this is good stuff ;)
deyomash 2 weeks ago
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imegatrone 2 weeks ago
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imegatrone 2 weeks ago
Your Video Is Very Useful Sharing
bundawartini 2 weeks ago
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bundawartini 2 weeks ago
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bundawartini 2 weeks ago
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bundawartini 2 weeks ago
4 people are classical
tesicnr 3 weeks ago 2
finished my physics degree a year ago this is second and third year material, hes a good explainer a recomend this to anyone revising.
NorfolkCatKickers 1 month ago
What kind of math is needed for this?
ICarnag3I 1 month ago
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JFStarwood 1 month ago
@ICarnag3I Linear Algebra
JumleBumle 1 month ago
nice vid
xtremetom180 1 month ago
What if we were to replace the surface of the Coin or Die, with a viscous fluid?
That it becomes non discrete.
Would the use of set still be preferred or could vectors be used?
VellianoRosso 1 month ago
1:24:10 "UHHHFFF!", "UHH", "FFF!", "ah"
BlogDeJoel 1 month ago
My interest in the bigger picture is growing day by day.
MrPEDOCTOR 2 months ago
i can build a dirthouse
Drugio24 2 months ago
I know kungfu...
Velvet3232 2 months ago in playlist Course | Modern Physics: Quantum Mechanics
A good introduction to this subject is"Quantum Theory: A concise guide for beginners"
pgb2323 3 months ago
This has been flagged as spam show
What would Jesus say ?
skepticalinquier 7 months ago
oh man, all of a sudden i got so sleepy... zzz.....
dirac17 7 months ago
This has been flagged as spam show
"Today, a young man on acid realized that all matter is merely energy condensed to a slow vibration — that we are all one consciousness experiencing itself subjectively." ... "Here's Tom with the weather"
sn1pe352 7 months ago
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voutasaurus 7 months ago
Don't you know how hard you whacked the electron with the photon? Can't you figure out the electron's velocity before the whack by conservation of momentum?
zeperf88 7 months ago
@zeperf88 No because an electron has an undefined state of momentum at any given time. You can only gather probabilities for different momentum states.
floopsie666 7 months ago
Sad to see a hippy lose his hair. What did he say about an Emu and and a Gnu in a four vector with c velocity?
mysticlawlotus 7 months ago
Ah, man. I love my limited intelligence.
He starts explaining and my mind is perfectly grasping everything, giving me metaphors to get how this works in the real world and suddenly I get to a point I don't understand and my mind goes "Wut" and I just don't understand anymore.
Hey, at least my work doesn't involve physics.
Ebvardh 9 months ago
the position and velocity of ass
gen6k 9 months ago
Thanks for the lesson
lpap 9 months ago
To nitpick something he said, basis vectors need not be orthogonal. In two dimensions, all you require is they don't span the same line.
jamma246 10 months ago
@jamma246 Oh, he meant orthnormal basis.
jamma246 10 months ago
@jamma246 they need to be orthogonal due to the practicality of not needing to calculate several integrals. He just didn't mention it at this point.
Sahrinzs 8 months ago
love the introduction of kronecker delta!
cesarjom 10 months ago
Susskind makes interesting generalizaion: (ab)*=b*a*... this implies non-commutative prop however for a 1-Dim complex a,b this is not true, they do indeed commute and (ab)*=a*b*.
It is not until we generalize complex numbers a,b to a higher dim 3-Dim or greater that we run into non-commutative prop. Let a be a quaternion such that a=1w+ix+jy+kz, over a vector space spanned by basis (1,i,j,k) where i,j,k are complex such that ii=jj=kk=-1 and ijk=-1. Only then (ab)*=b*a*.
cesarjom 10 months ago
@cesarjom He doesn't say that they don't commute. (ab)*=b*a* means that (ab)*=a*b* by commutativity of the complex numbers. Writing it that way doesn't make anything wrong, but it works for later on.
jamma246 10 months ago
@jamma246 - my only point (and I think I was not very clear about it) is that for higher dimensional complex numbers (eg quaternions having 2 additional imaginary terms), it is not true that (ab)*=a*b* if a,b are quaternions. For same, it is true that (ab)*=b*a*. This result is consistent with the fact that quaternions (eg a = 1w+ix+jy+kz where w,x,y,z are reals) do not commute, b/c in the basis (1,i,j,k) of a quaternion, ij = -ji while ii = -1.
cesarjom 10 months ago
When compared with all the other luminaries, Susskind certainly lags very far behind. This quality is apparent in his writings as well as in his lectures.. In my personal opinion, the reader doesn't get the same feeling of a powerful or brilliant mind, as when w itten by Einstein, Heisenberg, Bohr, Schrodinger, Dirac, Kaku, Lewin, Balakrihnan,Green, and countless others..
I hope to be able to endure his lectures and learn something from him. I also hope the would change my mind.
nementerc 1 year ago
@nementerc... note that a great theoretician does not neccesarily mean you have a great communicator (ie lecturer) particularly to the layperson. Such is the case of Dr Susskind, his insights into his areas of physics are priceless to graduate-level and follow physicists where he can provide much more detailed mathematical arguements... for the layperson there is not much advantage as Susskind lacks the eloquence and succinctness of say a Richard Feynmann.
cesarjom 10 months ago
why do I need a dual space if I want to define an *inner* product. cant one just stick to either the bra- or ket-space, i.e bra A | bra B or ket A | ket B
And why is
ket A | bra b of more interest than say bra A | bra b ?
mdinka 1 year ago
@mdinka The inner product is cancellative, degenerate, like multiplication of a vector with a dual vector or complex by its conjugate. bra a bra b, ket a bra b, and ket a ket b are, to my understanding, all outer products.
ket A bra B maps a ket v to ket A bra B|ket v. bra B|ket v is a scalar. Ket A bra B uses bra B to decide how much ket v should scale ket A. When you interpret ket v through bra A, you get a projection operator P = ket A bra A = P^2 = ket A bra A|ket A bra A.
LokiClock 1 year ago
@mdinka ... braA | ketB is just notation (Dirac notation) for the inner product, which is DEFINED as sum (over n) of (An*)(Bn) where An is nth component of vecotr A and note An is a complex number.
cesarjom 10 months ago
... or equivalently ketB is analogous to a column vector A. And braA is the transpose conjugate (*) of the column vector ketA. So in this matrix representation, braA | ketB is the same as our original definition: sum (over n) of (An*)(Bn). It does NOT make sense to write ketA | ketB... that would be like trying to multiply 2 column vectors (dim Nx1). Inner product is a number (scalar), so you must use Dirac notation that is consistent with that result.
cesarjom 10 months ago
1:13:10 so this is sum over instead of sum over i? Is this because vsubi was replaced with the braket?
kuzuboshii 1 year ago
it would be great if we could hear the questions being asked
peterpickaxe09 1 year ago
wow, quantum physics is basic undergrad linear algebra? This is so easy.
chrisahc 1 year ago
in formula L + - delta/ time
time is only numerical order of particle motion
particle does not move in space-time, it moves in space only
TimeEinstein 1 year ago
@TimeEinstein Space is only numerical order of particle position. Particles do not move in space, only position.
LokiClock 1 year ago
Beautifully clear.
wesselbindt 1 year ago
Always good to refresh my memory
PHDRelativePhysics 1 year ago 5
@PHDRelativePhysics
Less good trying to be a douche by knowing basic qm.
DasKrabbe 1 year ago
what level of math does this guy use in these lectures, cause i dont want to watch them all just to realize that he hasnt used any advanced maths.
stupidfleshmonkies 1 year ago
@stupidfleshmonkies There is no advanced math in QM. It is just partial differential equations.
floopsie666 1 year ago
@floopsie666 yea but does this guy use PDE's in these lectures.
stupidfleshmonkies 1 year ago
@stupidfleshmonkies
QM normally involves very complicated PDE's and easy ODE's; however in an undergraduate course you are given the answers to all the pde's, no real math is invovled - if you want math, don't go to physics. Granted its is interesting to note all the besel functions and field theory that goes into deriving QM.
FlamingPope 1 year ago
@FlamingPope so the solutions of the PDE's are given to you in undergraduate school for QM? (I wouldn't know I'm sitll in high school).
floopsie666 1 year ago
@floopsie666 if you know how to solve diff eq, (an undergrad physics requirement) then you can solve many problems of the schrodinger eq.
cesarjom 10 months ago
somebody stop joseftran
turfute 1 year ago 4
thanks standford university!!! words cant do justice to my feelings of gratitude so I'll keep it to just that: THANKS
Sakartvelo69 1 year ago
Anyways, forget about math. Let's go swimming :)
joseftran 1 year ago
.... differently too. Now, all this math looks like garbage yet it worked for the atom sized humans. Those atomic humans then try to understand our world which is really really big compared to them. So they take all that garbage math they made that doesn't make any sense to us and try to explain us but in their atomic math language! You see! They can't ! Cause there language is different from ours so they understand it differently and we just can't understand each other.
joseftran 1 year ago
.... looking at the math from another viewpoint we see a weird world. Maybe the world of the atom ? Just cause the math doesn't make sense doesn't mean it's wrong. Thus, in order to "really" understand we halfto not be human and think that apples can only fall from trees because what if the tree is falling from the apple? Try to think of it this way. If we were the atom then we'd have our own math system with numbers differently, maybe from 1 to only 3.14 then we'd operate on them ...
joseftran 1 year ago
Now to talk about something interesting. Our math is built around our perception and the answers are accepted when they make sense to our perception. However, because we can't seem to understand things outside of our perception....what if the real math was to be built outside of our perception such as 1+1 = 5.617 ! Then when you build all the imperceptible math at one viewpoint we see our world with all the exact same perceptions that were used to. However....
joseftran 1 year ago
Notice the f=. I did that on purpose. Even equality or assignment is fuzzy. Think of it this way. If you take one apple from one basket and put it into another basket do you really think that you took the "whole" apple and actually "put" it into another basket? Of course not ! All you did was try to put the apple into the basket, unfortunely it's not the same apple as the apple that was originally in the basket :(
joseftran 1 year ago
Unfortunately he is grossly wrong about how he constructs the math to respresent the laws of the universe. It's not quite that simple. 1+1 is not really 2. Therefore, the entirety of his lecture has to be scraped and redone from the begining. The actual math is to use something of a fuzzy number like f1 + f1 f= f2 where f is the "fuzziness" of scale. f is both fuzzy in delta time and delta space and delta anything else you can think of. Sorry people, nothing is simple :(
joseftran 1 year ago
I am a physicist. I havent been doing real physics for a while. For me these are just fond memories. I am quite astonished that none of this has slipped my memory. Susskind is a great lecturer. He really knows how to boil it down to the basic concepts, which are not so difficult. I am quite astonished that he is discussing the abstract hilbert space at considerable length, since these lectures are not directed to professional physicists. But, I like his approach.
bhigr 1 year ago 2
this is akin to getting stomped in the nuts for an imaginary amount of time
mahyarmohaghegh 1 year ago
Graham from the Isle of Wight, United Kingdom.
I know nothing about QM, but still consider myself interested in Science. Leonard is a very interesting lecturer, of whom I wish to know much more.
My interest in the bigger picture is growing day by day.
Thanks
Graham
grahamhallxyz 1 year ago
just to clarify, its behind him on the board at 1:40:00
unimoggie 1 year ago
@unimoggie Yes, I think it does. We know that alpha h star times alpha h is a positive real. He just stated that probabilities should also be positive reals, so I think it would logically follow that he means the complex conjugate. Also, he hasn't given any other definition of star other than complex conjugation. So why should we assume it has a new meaning.
haldarin 1 year ago
When he writes P = 'alpha star H' x 'alpha H', does alpha star signify the complex conjugate of alpha star, or something else? I am afraid my maths is very rusty and I may not have followed the lecture perfectly! Thank you :)
unimoggie 1 year ago
I would be nice if questions asked were written across the video, since audio of them is unheard.
Anyway, goooo Leonard! Quantum the hell out of those Mechanics!
RobotTed 1 year ago
@nickharvey7 Nope, the Uncertainty Principle is more fundamental than that, though he hasn't covered it yet. It states that the standard deviation of the momentum superposition times the standard deviation of the position superposition is >= hbar/2. As such, supposing you have an exact known particle position, the particle is in an infinite superposition of all possible momenta at that time. Crunching it through the Schrodinger equation gives a deterministic result for all future times.
hackulous 1 year ago
@hackulous Yes! but when the superposition collapses it will only have one position in space and time. Could this not be a new moment in time as part of the time continuum? Because classical physics is an approximation of quantum physics is it not possible that Heisenberg Uncertainty Principle is the same uncertainty that the observer will have with any future event?
nickharvey7 1 year ago
Could Heisenberg Uncertainty Principle be the same uncertainty that the observer will have with any future event? If time and the geometry of spacetime is continuously being formed by the momentum of EMR or light. There is no understanding of time in modern physics or why we have a future and a past. Could this be why we have the paradoxes of QM?
nickharvey7 1 year ago
@nickharvey7
Why specifically do you say,"There is no understanding of time in modern physics or why we have a future and a past". Are you talking about continuous vs quantized distributions?
Maybe time also scales with size.
QuaterionEM 1 year ago
@QuaterionEM I specifically say we have no understanding of time in physics because we cannot explain why we have a future and a past. We can look back in time through light years of space at the stars. But when we look down at the atom we only see probability. Could this be because Heisenberg Uncertainty Principle is the same uncertainty we have with any future event?
nickharvey7 1 year ago
@nickharvey7 (macroscopic) future as ALL probalities NOT YET measured is still dependant on the notion of time, i.e. not yet determined as in a discreet state by any interaction whatsoever in the NEXT instance of time just because this interaction has not yet happened THIS instant of time. And would this line of thought not do somewhat confuse relativity with QM? - or maybe it's THE Step to the ToE - Supertimesition perhaps? - honestly, me just getting more confused from lecture to lecture ...
roboflop314159 1 year ago
@roboflop314159 In this very simple theory creation is a continuous process and the flow of time is formed by the continuous inward absorption and outward emission of light or EMR. The process that forms Heisenberg’s Uncertainty Principle also forms the Arrow of Time!
nickharvey7 1 year ago
this is a very interesting subject and id like to learn it. but ts just too long complicated and hard.
andrew09211 1 year ago
at the risk of sounding slow. if i follow this correctly; it would seem that it would truly be mathematically impossible to violate the uncertainty principle since there would always be a value associated with you looking at the system.
fassterblade 1 year ago
They also could be called quantum coin, and quantum dice.
eaglefer 1 year ago
Comment removed
eaglefer 1 year ago
It's just the definition of the dot product in that space. As the guy is saying it satisfies the necessary requirements of a dot product. Dot products can be defined differently in all different kinds of spaces.
kaesspaetzlomator 1 year ago
@krastapopolos
The integral version and vector version satisfy the same rules. You can see in the 57-58mins that he does the dot product for vectors and that produces a sum. An integral is like a sum over an interval. Wavefunctions are infinite dimensional, the vectors aren't.
oppenheimer12 1 year ago
Comment removed
fantar132 1 year ago
@fantar132 could you elaborate because susskind is saying that indeed a single particle is affected by the uncertainty principle
thisislizzz 1 year ago
Comment removed
fantar132 1 year ago
Definition: a *vector space* is a set that is closed under finite vector addition (+) and scalar multiplication (.).
Definition: a *complex vector space*
is a vector space whose field of scalars is the complex numbers.
German1184 1 year ago
23:00 Are we done talking about vector spaces yet...
lstop1day9243 1 year ago
Why some people insist Susskind should explain "clearly"? QM is not something you can find the analogy from our macroscopic experience. Just get used to it.
myclicks 2 years ago 35
This has been flagged as spam show
""TO ALL PEOPLE WHO ARE READING THIS : DOSE THE ELECTRICITY OF BRAIN CAN BE HACKED VIA SOME TECHNOLOGY? Can ANY Microwaves or ELF Waves Manipulate the Electricity of the brain?
My Clear Question : Do some people Reading OUR MINDS And manipulating our subconscious regions of mind-brain via having the electricity of our brain in thier computers?
I hope for search, curiosity.
mrelectron111 2 years ago
@mrelectron111 good question hadn't thought about that i'm sure it migght be posible one day
1kingconan 1 year ago
Quantum Mechanics is a genuinely complex subject ~_~
Mattprole 2 years ago
@Mattprole Eucledian geometry is no less difficult, it's just more familiar.
Travellersfees 2 years ago
@Travellersfees I agree with you actually. y original comment was a bad pun
Mattprole 2 years ago
@Mattprole NOT REALLY I'M NEW TO THIS AND IT SEEMS SIMPLE
1kingconan 1 year ago
Complex as in complex numbers ... a bad pun
Mattprole 1 year ago
What a boring communicator. He may be brilliant and accurate... but his verbal flow is horrible, his train of taught scattered all over the place. Laurence Krauss is more interesting.
FreddyFuFu 2 years ago
Yes, an ingrate like you would like Krauss. Krauss the sniggering hegemonic iconoclast who, like Dawkins, Miller, Hitchens, Myers, has adopted the cynical excuse that the people are too stupid to understand and therefore must be lied to in order for their own good, oh and merely incidentally the aggrandizement of the issuing blind establishment whore. Krauss's bullshit is that he equates quantum fluctuations to 'nothing' so that he can hype his 'universe must arise from nothing' rubbish.
sustaincain 2 years ago
I know girlfriend: what a bummer! There he is describing how to manipulate the awesome fundamental inexplicability of existence in measurable terms and he has the audacity to not even be charismatic and funny and condescending and deceitful! Sheet! You should ask for your money back, and please, do put plenty of plastic sheeting down before you blow your brains out.
sustaincain 2 years ago
Wow... I guess Deutsch would say to both of us "in many other Universes, cain trashed Krauss and Freddy defended Susskind."
BTW, I only critiqued his communication skills... not the content of his lecture, which is priceless... like all good science.
FInding Krauss interesting does not equate to agreeing with him on everything.
Good day to you!
FreddyFuFu 2 years ago
Bless you fellow traveller, well met, and good hunting to you.
sustaincain 2 years ago
LOL
You have a lot of anger in you...have you been raped by an elephant or something?
O_0
perfectdonk 2 years ago
Nice one. Put up some identity, then we'd be inclined to give you some cool links depending on what you're into. Welcome anyway, its pretty mad out here, but you can learn a lot if you want to. More than one ever dreamt.
sustaincain 2 years ago
HAHA
"we" ?
perfectdonk 2 years ago
Truly excellent lectures invaluable if you are learning quantum mechanics. The logical next step would be field theory. It would be great if Stanford would provide this as a public service.
If any one can explain this complex topic Prof Susskind can.
luzzie9 2 years ago 2
This has been flagged as spam show
science suppression board for funds
bull shite =
QUANTUM MECHANIC, BLACK HOLES, BIG BANG, PARTICLES, 4 DIMENSIONS
GOOGLE:
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what's the point
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stephen crothers
phicromnoj 2 years ago
It took you three posts when you only needed one?
ST4524 2 years ago
Leonard teaches these topic so anyone can understand it. He is such a brilliant professor that it is like learning kindergarten.
jcbmack 2 years ago
You are right. These ideas should be taught in kindergarten, and not to these old people.
okaunis 2 years ago
I don't think anyone understands a word I write. Physics is kid's stuff. Try understanding human thought while you are human. As for Physics, humans are very advanced compared to other species, but it was not long ago that humans humans didn't know what an atom was. Humans think that Einstein was/is some sort of genius. He simply was not as closed minded as others.
okaunis 2 years ago
What a stupid statement ! How many kindergarten kids produce great insights into modern physics? None.
redtonto 2 years ago
I was KIDDING as in being SARCASTIC. But kindergarden kids do just as important work. The string theory cured no one of anything. It's as clever as many other "ideas" and in the future may well end up as a historical curiosity, just like the "radiator theory" of human evolution.
okaunis 2 years ago
Who said anything about string theory?
You were SARCASTICALLY saying that the whole of physics rests on trying to rescue naive realism until you bump into quantum theory? Why? Most people when they are SARCASTIC at least try to say something funny.
acr08807 2 years ago
What is the intent in the explanation of Quantum Mechanics?
NeoOneOrg 2 years ago
To teach QM, neo.
acr08807 2 years ago
But what is it that QM represents? The explanation for reality?
NeoOneOrg 2 years ago
It is a mathematical model that fits a number of experimental results. No experiment has ever shown it to be wrong. There are things that QM doesn't explain, though. Would you say that is an explanation for reality?
acr08807 2 years ago
All kindergarten kids have the same insights in physics... they correlate datasets from 3 senses to extrapolate a 3D world from 2D images and they postulate the existence of an independant objective reality... naive realism.
The whole of physics rest on trying to rescue naive realism until they bump in quantum theory.
Oh, there is movement called "taking children seriously" that might disagree wih you about the capacity for children to make scientific progress.
FreddyFuFu 2 years ago
Yes, what child hasn't independently stumbled upon Maxwell's equations or the laws of therrmodynamics?
acr08807 2 years ago 11
@acr08807 Yes I believe that we have missed any point within definng QM' this has more to do with how people are not using faculties and are simply being programmed within memorizations' without having any intrinsic fruitions within how the mind actually facilites and uses any kind of knowledge' this is definately a west coast thing' and I want to go to Stanford some day and get a degree for psychology' psychology is what? Dealing with any and all interpretations within any impression?
DrFruedienslip 3 months ago
@DrFruedienslip This has everthing to do with how people can and are being conditioned within any and all charaterisations to any identity; this another part within how capitalism and despotism go hand in hand while lendiing to socialism; which is all based within fear in one way or another' which has everything to do with social separations withn economic degradations though each part supports the whole within any existence'
DrFruedienslip 3 months ago
@DrFruedienslip You shouldn't study psychology, you should syudy postmodernist humanities. You'll fit right in.
acr08807 3 months ago
@acr08807 What Psychology? The one we live in? Does one know what a question mark represents? Postmodernist humanities? What does this mean? Any principles within human human are unchanging is should become any point to QM' Why did Einstien say' God doesnt play dice with the universe? All Im going to say is that construal is what we are referring to when it comes to any mind within reasoning anything within any existential experience' Intrinsic Anthropology' and economics explains despotisms
DrFruedienslip 3 months ago
@DrFruedienslip I doubt seriously that that's "all you're going to say."
acr08807 3 months ago
@acr08807 Oops I messed upo on a couple words' However Intrinsic Anthropolgy is a clue here to a book thats being written' have you ever read Sarum? any world view looks at the past and the present wanting to know what is or isnt predictible' the metaphysical side to quantum mechanics has everything to do within defining human character traits' which is what philosophical statements exemplify' why has there seemingly alwaysbeen the argument over defining God' is god truly a person or Theoretical
DrFruedienslip 3 months ago
in fact...kids or not...our hunter gatherer brain is NOT evolved intrepret quantum phenomena...............
independence8 2 years ago
This has been flagged as spam show
@independence8: "our hunter gatherer brain is NOT evolved intrepret quantum phenomena"
Sure it is. QM is counter-intuitive, but not outside the realm of human understanding.
joeloud1 1 year ago
And this is an instructor at Stanford? He can't get his thoughts straight.
okaunis 2 years ago
And he can still handle it. Usually when "you can't get your thoughts straight", you can do only simple things, like washing dishes, and can't explain relativity or quantum mechanics. And he just can do it that easily. That's the level he's on. Einstein said, if you can't put it simple, you don't understand it well enough.
Btw I think he could get his thoughts straight any time if he would have to.
MoZo84 2 years ago
Well I guess he'd better be good at washing dishes. He's taking a lot of time to explain something very simple.
okaunis 2 years ago
He's not just an instructor at Stanford. He's Leonard Susskind. He's one of the three people that invented string theory. He's no slouch.
aaronasterling 2 years ago 46
It took three people? Maybe he needs the other two to help him explain.
okaunis 2 years ago
@aaronasterling yes, that's why he is worth being listened to. We must read and listen to inventors, not to just learners.
fialkool 1 year ago
@aaronasterling you are right, I don't think QM can get clearer than this.
xenoepist 11 months ago
Yeah I searched him on Google, the instructor has done a great deal it seems.
Mattprole 2 years ago 2
you can learn any university course you want for free, if you put in time and effort, the DEGREE is what you won't have.
conman2317 2 years ago
How many people with no degree discovered more than those WITH a degree? Many! And how many are/were greater experts in their field with no degree? You have all the time you want to research this. The percentage is far greater then you thinkl.
okaunis 2 years ago
I understand that, but the Degree is important, that is if you want to be hired under your particular field. You will not be hired despite your intelect and research over someone who has a Degree.
conman2317 2 years ago
Getting a degree is FAR more than casually listening to lectures. The courses themselves demand that you 1) do much supplementary reading 2) work through difficult homework problems and 3) take midterms/finals to pass. Not to mention the countless hours of laboratory work and student research which are required. Merely listening to a lecture, while both fun and informative, is actually a very small portion of the educational experience leading to a degree, which is why employers rarely go for it
drillsargentadog 2 years ago 2
hey guys how can i find more information about the course, like transcripts, textbook used, lecture notes, assignments, course web page....etc
AhmedSabry28 2 years ago
you have to pay to do the actual course so getting that stuff is unlikely.
scatter223 2 years ago
try going to there site and sarch this lecture.
laputahayom 2 years ago
unable to download these videos
i have low bandwidth net connection so i used dap
but halfway through it started asking for authentication
cant download through itunes either because it doesnt support pause/resume
i have slow internet but i want these videos
plz help
plkarthat 2 years ago
download youtube downloader 3000 if u really want the videos
mrmonkeyman 2 years ago
Orbit Downloader works too.
openuniverse2003 2 years ago
Thanx for the info on orbit downloader works way better ;)
mrmonkeyman 2 years ago
This has been flagged as spam show
J barret = a shady immoral lying conspiracy theorist..
Religion will never win a philosophical debate nor a scientific debate (especially not with Idiots like Kevin J barret , ahmed deedat etc. LOL)
If you wanna believe in fairythales and DONT INTERFERE WITH PEOPLES LIFES AND HUMAN RIGHTS, fine.
Dont expect to be taken seriously when trying to debate on an intelligent base, since all these guys are doing is TRYING TO FIT IN PSEUDO SCIENCE AND HOCUS POCUS to PROVE their god,keep trying HAHA!
ispaniola 2 years ago
This has been flagged as spam show
heres something interesting about ISLAM and what we muslims know regarding the universe and its physics and paralell dimensions and beings -read article "Quantum Islam" by Dr Kevin J. Barrett also check out Gordon Creighton's essay: The True Nature Of The 'UFO Entities. and you'll soon discover ISLAM'S authority and unlimited knowledge on everything seen and unseen.
4unitedMAN 2 years ago
J barret = a shady immoral lying conspiracy theorist..
Religion will never win a philosophical debate nor a scientific debate (especially not with Idiots like Kevin J barret , ahmed deedat etc. LOL)
If you wanna believe in fairythales and DONT INTERFERE WITH PEOPLES LIFES AND HUMAN RIGHTS, fine.
Dont expect to be taken seriously when trying to debate on an intelligent base, since all these guys are doing is TRYING TO FIT IN PSEUDO SCIENCE AND HOCUS POCUS to PROVE their god,keep trying HAHA!
ispaniola 2 years ago 3
This has been flagged as spam show
then you dont know ISLAM!
sorry for YOU godless soul!
4unitedMAN 2 years ago
hey dude chill...
listminusv 2 years ago
shut up preacher, leave us alone
devotedpupa 2 years ago 2
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you fuckers forget the dark ages all too quickly!!!
4unitedMAN 2 years ago
what are these dark ages?
voodoocigam 2 years ago
This has been flagged as spam show
So I guess you are here to remind us of how they lived in the middle-ages (-east?). Your narcissism and anger stem from fear. Your fear is of a paranoid type (everyone is "evil") and a result of latent homosexuality, which stems from unresolved love-hate feelings towards your overly-severe father. You hide all of these character *flaws* behind the "veil of Islam", but the truth is you are a coward who projects all his hate onto everyone else but the person who deprived you of a mind of your own
PrettyNeckslashes 2 years ago
wow, that was hilariously off the mark.
4unitedMAN 2 years ago
or was it sadly spot on the mark...hit a nerve?
PrettyNeckslashes 2 years ago
no, really. im fine:)
4unitedMAN 2 years ago
he always finds coin
enricfemi 2 years ago 2
This has been flagged as spam show
DOES YOUR PROFESSOR TALK ABOUT ALIEN TECHNOLOGY like most of the AMERICAN geeks and soothsayers !!!
nibus9 2 years ago
The universe is an impossibly large 3D object spewing itself into itself, thus the 4th dimension.
deltro 2 years ago
How can it be 3D on an 11D plane?
boredman443 2 years ago
all of the forces are the universe abstracting from the 3D matter the 4-dimensional destruction of it. By holographing properties that we observe from particles, we observed that their activity requires 11 dimensions to describe, but it's all meaningless to us, because in reality it's just the completely incomprehensible barrier necessitated by 3 spacial dimensions.
deltro 2 years ago
أشهد أن لا اله الا الله وأن محمد رسول الله
black0jackass 3 years ago
I like the teaching style but some of the stuff he puts on the board doesn't connect to other things previously discussed...Idk it might just be me...
666GOREGRINDER666 3 years ago
No offense meant, but what is your background in physics? The first couple of lectures he is leading into vector space discussion. You need a strong base in complex numbers to under stand more advanced vector space ideas such as the "space time cone". (v1 v2 v3 v4)
DruidicSlave 3 years ago
I am currently majoring in particle physics actually. I'm starting up quantum mechanics this coming semester. I was just voicing my opinion. Sorry. =/
666GOREGRINDER666 3 years ago
Sorry? Hey wasn't attacking ya just wanted to start a convo. ROFL!
DruidicSlave 3 years ago
if we consider dimensions in physics as analagous to dimensions in mathmatics. we could assume that time is a fourth dimension and that quantum behavior shows us a hidden 5th dimension within time. the hidden dimension in time is when a quantum movement cannot be reversed because it has been observed.
if we extrapolate from this we see that the 5th dimension is the observer effecting particles moving in 4 dimensions.
greycloud24 3 years ago
But dimensions do not see as we do. They exist and are, for lack of a better term, seen by us as existing in and around and on and under and as eachother. It's hard to visualize but I hope you can understand my thinking. Wait! I think I've got it. Imagine a two-dimensional plane and a point on it. You have that point and it's all good. You add a Z factor to the point and it is now Three dimensional. You add (there's no symbol for time!?!) a fourth value and it becomes possible in our understand-
boredman443 2 years ago
ing. The fifth dimension must therefor be -- Oh, sorry, reading up on the fifth dimension, I found out that the fifth dimension is the probability dimension in some theories. If that was what you were refering to then you are correct. In a sense. Before I proceed and make a fool of mysself, could you explain in more depth, what you meant to say.
boredman443 2 years ago