Classical Mechanics | Lecture 1
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- Опубликовано: 29 июн 2024
- (September 26, 2011) Leonard Susskind gives a brief introduction to the mathematics behind physics including the addition and multiplication of vectors as well as velocity and acceleration in terms of particles.
This course is the beginning of a six course sequence that explores the theoretical foundations of modern physics. Topics in the series include classical mechanics, quantum mechanics, theories of relativity, electromagnetism, cosmology, and black holes.
Stanford University
www.stanford.edu/
Stanford Continuing Studies
continuingstudies.stanford.edu/
Stanford University Channel on RUclips:
/ stanford
711,000 people viewed this and learned at least a little bit in a very short time. It was a free class taught by an extremely educated man. Imagine the world we would live in if we had this kind of access to every class
Notes about lecture:
conservation law
conserved quantaty
allowable laws of physics, allowable rules
25:40
non-allowable law (in classical physics)
can't retrodict the past (opposite of predict)
non reversable
if reversed, unpredictive (don't know this or that comes next)
29:20
predictive one way, not retrodivtive other way
not reversable, "I" don't call it irreversable
30:10
classical physics doesn't allow probability
conflicts with the rules of classical mechanics
quantum mechanics are not deterministic
ambiguity in knowledge of initial condition, so from this statistics in classical mechanics despite deterministic
33:30
how precise do you know the initial condition, this determins how far you can predict the future, example three day weather forcast
other way around, if you know how far you want to predict, then you can determine how exact you need to know the initial condition
35:50
allowable, if every state has one incoming and one outgoing arrow
next example: point particle(s) moving in space
37:30
first some preliminary mathematics
vectors, coordinate systems
coordinate system: describing space quantitatively
space with three dimensions/coordinates
but we are perfectly free to think of systems higher dimensioned or lower dimensioned
38:10
we are interested in describing the basic pricipals, so we don't have to restrict ourselves to specific examples
a particle can move in one dimension, it can move in five dimensions, but for now we use three dimensions
39:30
three coordinates, doesn't matter where we put the origin, but it's easiest to put it at the (? 0 location)
the three axis are mutually perpendicular
label e.g, x, y, z or x1,x2, x3
40:00
still ambiguity about the rotation of the axis, which direction they go in
fixing the origin, we also have to fix the orientation of the x,y,z axis
theres a convention, right handed coordinate system, if you pick x and y, still need to decide is z pointing in the blackboard or out of it, we settle at right hand, x thumb, y inex finger, then z middle finger points out of the board towards us
this is the right hand rule
another convention, for distance we choose units
41:50
point is labled by x,y,z, thats also how we describe a particle
43:10
what is a vector
has both length and direction, for example a position of a point, relative to it' origin, magnitude is the distance, and it has a direction
don't think of a vector of being located anywhere
43:55
vector is the same, no matter where it is drawn in space, doesn't need to be drawn in space
vector labled by bar on top, more precise a little arrow
it could e.g. be velocity, it could be acceleration, it could be an electronic field
it's got, length/magnitude, and it's gotndirection
47:55 (see formula) length equals square root the sum of squares of its components
adding vectors, multiplying vectors by numbers
53:30
VectA+VectB=VectC
VectA*VectB=AMagnit.*BMagnitude*cos(winkel feda) "the calculated dot product"
the product of two vectors is not a vector, it's a number
1:00:00
we can display the dot product in component form
VecA*VecB=Ax*Bx+Ay*By+Az*Bz, you can prove this with a little bit if trigonometry
VectA*VectA=AMagnt.*AMagnit.
1:08:40
The velocity is the time derivative of the position
Dot means derivative with respect to time (so this does not have to be writtenover and over again)
Velocity is x of i dot (x1, x2, x3 for the coordinates)
1:13:50
acceleration is derivative of velocity or second derivative of xi, so it's written x with 2 dots
X - position
V - velocity
a - acceleration
r-Vector for radius, positiin vector
1:16:00
Formula of an object falling in gravitational field with constant acceleration,
xt=a+bt+ct2
uniformly accelerated particle, that has acceleration 2c
1:18:00
Circular motion
x+y achsis, the angle increases linearly
feda=omega*t
2Pi/omega=period
omega is the angular frequency
X=cos(feda), y=sin(feda)
derivatives of trigonometric functions
velocityX=-omega*sin(omega)t
angle between velocity and position?
more on velocity, acceleration, calculated ways for this shown
U saved my life bro
Lol. It's "Theta" not "feda".
Susskind dinleyen türkler var duygulandım :D
holy ish dude i cant believe u took the time
Ayıp ettin
I love this man. The way he explains things, the way he talks, the way he thinks, the way he moves, his wisdom. Having watched many of his lectures, I feel a deep friendship without ever having met him in person. Thank you so much, Lenny.
How are u doing now, 3 years later
@@YasoHisham They got married.
@@mtmind6560a beautiful relationship blossomed after such hard Dick riding
I remember watching videos like these before college, which definitely kindled a passion for physics and math deep inside me. Then I also started reading advanced books, which were not even part of the course syllabus, for example the famous series of books published by Lifshitz and Landau.
Among other things, I published the step-by-step solutions to many of the classical physics problems in the first book "Mechanics" in an online course on Udemy (called: "Multivariable Calculus and Classical Physics problems"), which deals with the mathematics and physics of rigid bodies, non-inertial systems, and much more. This is to say that videos like these can be very helpful in inspiring youngsters to appreciate physics.
The Udemy course you mentioned is not showing up. Is that still available ?
@@mpay2874 Oh I see, now it has a different name, it's called "Multivariable Calculus and Classical Physics problems", I decided to merge two courses into a single one, due to the strong connection between the two. So, yes, it is still available.
I'm in final year of my high-school and I'm slowly starting to love physics. Thinking about studying physics in undergraduate. So, spending my time watching these lectures.
49:05 Yes professor, your lectures are like the music that one want to hear over and over again. ❤️
First 16 minutes is the most succinct and persuasive explanation for conservation of energy I’ve sat through. A lot of people tend to explain it through tautologies.
Extremely thanks for providing such quality content for free of cost and enabling it to be accessible from everywhere.
#LovefromIndia
Nandha Kumar yes this is one of the great things about our world today
❤️
Thanks Stanford. These lectures really get you interested into science and just the aspect of being in a university itself.
Coin and dice configurations and laws of motion, conservation; infinite configuration space 22:00; non allowable laws, reversibility 26:00; vectors 37:30; particle position and motion and acceleration 1:05:30; 2 examples: motion on a line, circular motion 1:15:00;
Native English speaker and I literally just learned the word 'retrodict' (opposite of predict) from Lenny. The perks of this class are boundless.
Not a native speaker and I learned die and retrodict too
hello brother
You are the definition of people who are awesome, Professor Leonard Susskind.
LONG LIVE Leonard Susskind.
We need you like how we need water to live.
100%
Thank you Leonard and Stanford for this. The extras and insights mean a lot. You could lean this stuff from a Dover reprint, but learning it on a trajectory towards Scrodinger and company really helps one focus on what counts. I have been able to make quantum work for a long time, but I find myself returning to the roots over and over again to regain a sense of what I'm actually doing. I think lecture series like this are invaluable for contributing towards a future in which a significant subset of us understand what the world we can make claims about actually us.
jesus this is incredible
it's like watching the hulk trying teach someone how to lift a 10lb dumbell
Super N0iS3 😂 lol bro
@Andrew Walter III Kaamo 'D La Simmetrie what the fuck
@@ForeverStill_Fan1 and physics.
@@Joepage69 Don't use phone then. Be a Priest.
Without Physics you are still trieng to use Pigeons as mail man.
@@sadunfdo2888 physics is very much the unknown that was my point it changes all the time
I clicked classical mechanics and I'm watching graph theory. This is gonna be good!
One of the World's leading Physicists and Teachers, showing how to teach Science
46:00 When a world-leading theoretical physicist struggles to draw a vector in three dimensions, there's hope for us all.
it's normal. My grandfather Ph.D in his 80 can't even draw a 2d vector lol
JLongTom Lenny in perfectly imperfect!
Даниель Крузе (But u didnt say what area your grandfather specialised in, lol.
not in art ^
JLongTom haha
These lectures have changed my life! Watching this feels nostalgic!
53:30 That little slip from his Quantum Mechanics lectures
Christopher Soelistyo I know this is a super old comment but HAHA I saw that.
Thank you stanford university for making this free to everyone, i decided to study physics however had (in germany) to decide between chemistry and physics as a school subject, i chose chemistry inorder to at least have some fundamental knowledge about it. Now i figured out that german university have their lectures uploaded however only on private servers which are unacessable to anyone whos not in their university.
Thanks for giving me the chance to learn the basics to prepare for university
I really like the book as a companion to these lectures. It gave me deeper insight in some physics concepts that I used to just "take for granted" otherwise. The exercises also help for that matter and I can't wait for a quantum mechanics sequel and the rest of the series.
For those, who are starting this course..... It's very slow and a bit dull, But it's THE best. He won't show you experiments and stuff , but all your common questions and misunderstanding will be addressed in this course. Really it's the best.
Indeed your lectures are amazing everytime we hear them.
Finally I found someone who is going to teach me the concepts in math I need to understand my big love, astrophysics, a little better. That it's such a famous physicist, the better.
I'm somewhat proud I still remember and understand most of what he talked about in this lecture although I graduated from high school 38 years ago although I never really needed this since then.
listen to startalk if you love astrophysics!
ozdergecko the Closer to Truth channel has a lot of good conversations about cosmology and astronomy stuff.
@@tomstalley3179 can you comment the link of the channel? or is he a person?
Puspita Das just search ‘startalk’ kn RUclips, it’s Neil degrasse Tyson’s channel
Just 10 minutes in, I already have a feeling I'd learn more once I finish watching this vid than 10 hours in class...
Wow. That cleared up a lot for me. I'm looking forward to the next lecture.
This is invaluable, i love learning tho I cant afford to go to a big university
In
r u alive now
Bad for you to not be french
You can apply for financial aid
@@jolanmoussier9267 what?
Last 15 minutes, describing of circular motion, was awesome! Everything become clear!
This is amazing. Big Thanks to Stanford and to L. Susskind.
I've never seen a video on classical mechanics that quite starts like this, informative
Highly insightful lectures I ever came across, thank you sir for your work
He is always extraordinary..he always find the simplest version of explaination!!if anyone don't understand him,he never understand physics.
Put it at 1.25 speed. Saved my life.
+Klanos 2x and 1.5x for me, but I had to go back to the stuff on dot product and proving the law of cosines cause I was playing Factorio and not paying attention. I love the speed feature of RUclips. I feel like I have been robbed of some of my life because I didn't discover it sooner xD
+Klanos You, my friend are a fucking genius and I would forever be in your debt!
thank god i went down here before i saw the vid
Thank you so much!(:
Great suggestion. Thanks.
Professor Susskind, thank you for these videos. Theoretical Minimum Classes suit me to a tee. I really like them.
These videos are absolutely fantastic. Leonard Susskind is amazing!
This is fantastic, thanks to Stanford and professor Susskind :)
Leonardo,your lectures ARE music to our ears
49:09
Such a good analogy. And yes, Prof. Susskind, your lectures are like good music. Bravo maestro and thank you.
This was hilarious
Mike from Breaking Bad
Now , I can't unsee😂
Put your pencil away Walt. I’m not having a lecture with you.
@@IAyala1010💀💀☠️
No half measures walter
Once again im glad to find a lecture from stanford to help me learn more
oh its unbelievable... Thank you so much to Standford and this gentle man
I would like to thank the professor for his nice and interesting lecture he did!!!!!!!!!!!!
53:25
HAHAAHA best thing to write in classical mechanics.
Susskind: *show a group of people how to draw a simple 2-dimensional graph*
Also Susskind: *Assumes that the same group of people can differentiate trigonometric functions*
@@hiruki8 u didn't get the joke lol. Susskind tries to explain simple stuff and skips over relatively advanced stuff ( students know both) but just the way he is going on
@@sirius3333 I think she just explained it further
This is the thing with top Institutions... They teach you 'how to think' rather than what to think.
This guy teaches classical mechanics in one class and can teach string theory in the other, hat's off to you
I had lost my way and my love of physics due to depression. Decided to take a break from my astrophysics studies for a year. I think I will spend the year going through his lectures just to see if I can fall in love with physics again.
if u dont love physics, u literally dont want to understand reality, and that's like death
Loved the lecture so much.
53:25
That's what happens when you do Quantum mechanics alot
This made me laugh 😂
hahah!
Hey do u know what the general eqn was for the six-sided die? I cant figure it out
Ah my god
Which is easier, classical mechanics or quantum mechanics? I am only just today starting to study classical mechanics.
Finally something that isn't boring!!! Hi I'm 15 years old, and thank you internet for quantum mechanics, Now let me learn this first so it makes more sense...
5 years later.. How did it go?
What a great lecture & what a great lecturer.Thx.
thank you so much..... I learned many new things about vector's,before which I didn't get even after watching many other videos.....you are awesome...... :)
it always music to my ears , thank you very much
My brain lasted for 55 minutes. Started to watch bits again more to try and understand. Great lecture.
[Paraphrased] "There are some things you only want to experience once, like a book. You don't want to read the same thing over and over again. But there are other things, like music, that you'll want to listen to continually because it just feels good. I hope my lectures are like that... (paraphrased)." Why yes, Professor Susskind, your lectures are a treasure to listen to. Stanford for the win. :)
A wondrous lecture in classical mechanics
The book is called The theoretical minimum. Authors Susskind and Hrabovsky. The latter added some extra mathematics parts where needed. Electromagnetism is discussed, Hamiltonians, Poisson brackets etc.
So In Love With Leonard Suskind.
Wonderful Lecture, thanks for the laws of motion lecture.
this is such awesome content, thank you so so much !
didn't know mike ermanthraut had the best classical mechanics lecture series on youtube
According to this source, dice was once the plural of die, “but in modern standard English dice is both the singular and the plural: 'throw the dice' could mean a reference to either one or more than one dice.”
Time in nature might not actually be the abstract of perceiving it as going back or forward to actual events but instead are actually the observable chronological movements of objects that are speeding up or slowing down "DEPENDING" on the level(amount) of gravity and perhaps G-force that's constricting or not constricting the atoms that gives the "OBSERVABLE CHRONOLOGICAL MOVEMENT" we all see around us
Confused? Sloppy? Look at his lecture on 'Demystifying the Higgs Boson' - Of all the lectures this was the clearest overview of all of the great rash of such lectures that came out this year. I find the lectures leave me just enough to think about and sort out myself. I am a big fan.
I am very much interested in mass, acceleration, force, distance and energy. I like this video. He explains in very simple manner.
I really feel like a turkey sandwich right now.
Comprehensiveboy Comprehensiveboy haha
me too
While watching this video, I feel like eating a wrap with chicken, spices, lettuce, sauces, etc. Add chips (French fries).
@@pinklady7184 Chips. Luvley
me too bud
I agree, Lewins is a great teacher as well, he's awesome.
Yes, but perhaps the world is full of people who do not have the same grasp or perspective. Plus, one can never over emphasize the basics. This is what separates great teachers from ordinary ones. I find that a lot of the students brush through the basics and find later that they do not have a deep understanding. The concepts of state/phase space are actually not as simple and are so critical in understanding a lot of the world, it is worth spending some time on.
He is a great teacher!
He look like mike from breaking bad
exactly what i thought :D
AyoJeffy He IS Mike from Breaking Bad
nah he looks like mike from better call saul
Admit
Was thinking this watching season 5 of community today .. Sounds like him anyways
Well I am a high school student and I am glad that some great universities give a way knowledge for free. I love Walter Lewins Videos he is a great lecturer but they are limited to classical mechanic and electromagnetism. nothing complicated just freshmen's physics.
Could please activate in the video the option of automatic subtitles, that depends on the administrator, if they do not activate the other people does not get that option.
Podrían por favor activar en el vídeo la opción de subtitulos automáticos, eso depende del administrador, si no lo activan a las otras personas no le sale esa opción.
Loved the way he forgot and put ket bracket instead of modulus at 50:00
at 19:03, the laws of evolution for die world are categorized by number and TYPE of cycles, e.g. there might be three cycles: one 1-cycle, one two-cycle and one 3-cycle, like his example but there could also be three 2-cycles, so it is more than just the number of cycles - as he hinted.
Best teaching ever.
The point of using modulo arithmetic is that you don't even need to assign value 6 on the dice to 0, because 0, 6, 12, etc. are considered the "same" element (they belong to same equivalency class).
my like was the 7,000th. feeling very special.. lol
Stanford, thanks for sharing these priceless knowlege with the world..
How I recommend watching these videos:
1 Get some notebook paper.
2 At the top of every sheet, write the RUclips video's web address, RUclips Channel & video name.
3 If Prof. Susskind writes it down, you should also write it.
4 Write a timestamp on the left side of your notes so you can easily get back to a given subject.
5 Pause when needed.
6 Re-watch a section if you're still unclear.
7 Go to Khan Academy if you need to brush up on, or learn new math concepts ( ruclips.net/user/khanacademy )
MikeRoePhonicsMusic Thats exactly what I did, but with another youtube channel named Prof. Leonard, he teaches calc, great teacher btw. Ive filled 3 books worth of calculus, im at calculus 2 rn.
OneInfiniti MathBoi I watch Professor Leonard.
I agree Prof Superman (Leonard) is awesome!
Camera guy gets a check+ for awesomeness.
1:23:33 Actually, the dot product being zero isn't enough information to draw the velocity vector. The sign of vx tells you what direction the perpendicular vector is pointing in.
I feel my IQ rising by just listening to his voice. His lectures are amazing.
Greetz from a german science channel :)
Top notch lecturer♥️
Searching Amazon for dental pliers to pull my molars. Thought I grasped the concepts from Dr. Lewin. Going on to a different concept of grasp.
I am loving this
Awesome lecture!
You speak a tune with your voice so yes you make notes and numbers sounding like a song 🥰
YES THANK YOU STANDFORD! Learning!
"Thinkwell". It's online lectures with a fantastic instructor. Not sure how much it is since my university uses it as a supplement to the class, but it is probably worth every penny. It has made calculus my easiest class. You'll be knocking derivatives out of the park in no time. Just google Thinkwell calculus.
thanks for sharing Stanford
Good lecture. Helped me a lot. Just need to brush up on my calculus for derivatives of trigonometric functions.
Sam Smith if you know calculus and linear algebra the world of physics is more open to you
The Physics Connection Differential equations and other advanced math such as complex analysis and topology make physics easier to understand.
No tiene fuersas
No tiene fuersas el motor
Ke puedo ser pera mi troka
Thanks for your work : )
Lloyd Smith you have the Coolest channel ever !!
Excellent lecturer
1st of all. Thank you You are one of the greatest teachers I've ever come across. You love this Sh*t and it shows. I have one question. Do you mind showing me the equation of the simple rotating dice example. The one where 1 goes to 2 which goes to 3, etc... I apologize I am but a lowely plumber and electrician. I have been extremely interested in general relativity and quantum physics for over 30 years but the equations are over my head. Thank you
"Mechanics is basically a set of rules about what those laws of motion look like" ❤️
I'm 14. I don't understand everything, but this stuff is presented really easily and Prof. Susskind is great so I probably get at least 75% of this. Can't wait to go to university. ;)
tomtucjr are you happy now , 6 years later . are you in a university ? opted for STEM ?
Imagine explaining physics in a simplified way thanks alot
The question I need an answer for…on what type of machine..matter…system whatever..can we apply those equations and rules??…I don’t want to study mechanics I’d rather experience mechanics…
carrying on from lower post ,if a speed is constant then i'm intuitively confident that the G-force will remain and acceleration would "NOT" be a factor "IF THERE ARE NO OUTSIDE FORCES LIKE ATMOSPHERIC FRICTION"-An example would be the vacuum of space that would not require acceleration to continue the G-force effect once the optimum speed has been obtained- -So provided the atomic clock that slowed in the plane had continued motion(IN atmosphere that creates friction acceleration would be needed for constant speed "BUT" in vacuum of space "ACCELERATION WOULD "NOT" be needed for continued "PALPABLE/OBSERVABLE" G-force effect once the optimum speed is obtained) the atomic clock's movement of atoms "MIGHT ACTUALLY" be constricted by a miniscule G-force effect , thus slowing down the chronological movement of hands or digital face-Even light is affected by Gravity (as in gravity lensing) and i should imagine it's restriction would include anything observable by us-In the "MOVING" airplane cabin air and other unseen things may be the "OTHER" key factors interacting with motion to create the miniscule G-force effect that restricts the movement of atoms in atomic clock that creates the slowing down of it's actions as a clock-THIS might be the reason for time slowing down when movement is applied "OR" extreme gravity is applied and not the classical idea of the ability to go forward or back in time to see past or future events-THE black holes theoretically churning out constantly huge numbers of these gravity repeling particles and any matter with gravity to cause the expansion of the universe- "raw" Quantum particles which are in unusually small size repelling gravity and any matter with gravity(unlike the ones on earth )
1:06:15 : the r doesn't stand for radius. The official explanation is that the position of a single point in space can be defined by three different rotations defined in a rotational matrix. So the r stands for rotation
Very well explained ❤️❤️🙏
I'm taking this class in the spring and I'm scared. I've been told as long as I can solve differential equations I'm good but I still think I'm going to struggle. Anyways I think that these videos are going to help a LOT.
Ummm, hello KingArthur...
It looks like we had the same idea...
Great work