Lecture 1 | Modern Physics: Special Relativity (Stanford)

This is the triangle paradox.
There are 3 lights in the form of a triangle. A, B, and C are lights and are stationary with respect to each other. S1, S2, S3 are spaceships. S1 is moving from B towards A. S2 is moving from C towards B. S3 is moving from A towards C. A, B, and C flash simultaneously in the frame of reference that is at rest relative to these lights. So in the frame of reference of S1, A flashes first followed by B flashing. In the frame of reference of S2, B flashes first followed by C flashing. In the frame of reference of S3, C flashes first followed by A flashing. So the sequence of flashing is A, B, C, A. But wait! A flashed first. How can it flash last? How can A flash both first and last? It only flashed once in the frame of reference that is at rest relative to these lights. Therefore there is a paradox.

Two ships passing each other.
Ship1 at rest at top:
T--------------------N
<----- N----------T
Ship2 at rest at bottom:
T----------N ----->
N--------------------T
The moment when T1 is lined up with N2 must be the same moment in both frames of reference because there is only 1 moment when this occurs. There was some point in the past when N1 was lined up with T2 according to ship 1 but not according to ship 2. That is impossible thereby proving that special relativity is nonsense.

Thomas Jennifer Hall Carol White Charles

just assume aether is a fluid that fills the universe. everything is a wave 🌊 in this aether. relativity is just wave mechanics 🧰 😊

There are a lot of stupid students in class.... Some of them want to show that he has better intuition then Leonard, but no one will agree to him. Even though log scale and Persian is meaningless for this explanation, they want to brag about their poor knowledge.

i am pretty sure when he gave this lecture he was not expecting an 8th grader to watch this but here we are

This kid is just asking questions so Leonard thinks he is smart lol

Although the constancy of the speed of light is usually an axiom, I prefer to think of it as a consequence of trying to represent time and space with the same units, so that they are the same thing, and assuming that in such units there is interchangeability in the equations of physics, which means there is symmetry with respect to the bisector, which represents a point moving at speed c. So c is the same in every reference frame. And if we assume space and time are the same, it makes no difference to invert the space and time axes. So a particle moving at speed V>c is perceived as a particle moving at speed v<c: each frame has two axis, and we can't decide which axis is space and which axis is time. The one representing motion at v<c (the one in the time zone) is a time axis, and represents the motion of the frame. The other representing motion at V>c (the one in the space zone) is its space axis, and represents its present. So no motion at speed V>c represents a moving particle, because it simply becomes the set of events representing the present of the particle, therefore causally disconnected from the particle. The actual particle is always that one in the time zone.

such a helpful lecture learned much from this lecture

I won’t explain inertial reference frames any further, except…

proceeds to describe inertial reference frames in great detail

Sir jii you are the great❤️

am i the only one that likes to fall asleep to this . makes me comfortable

Very interesting and very nice

I cannot believe that this respectable professor goes with the student argument that x' is bigger than x to modify the equations! A little more rotation of the second frame in either direction will make that argument go down the drain. The coordinates in the new frame are found by simply knowing that the unit vectors of the original frame are multiplied by e(jΘ) and concluding that x' = xcos(Θ) + ysin(Θ) and y' = -xsin(Θ) + ycos(Θ)

Y his mouth sound like that 😂😂

whats the difference between this playlist and the one that cam out in 2012... why are there 2 different lectures by the same person on the same topic

Who's watching in 2020 during quarantine?

Thanks for inspiring people to pursue science. We need more professors like him.

The work i do has absolutely nothing to do with physics but I still enjoy watching this infinitely more than CNN.

I consider him my mentor even if he doesn't even know me. You're amazing, Leonard.

Vladimir Putin teaching Physics.

Peera manam dy..😍

Ayt ye calisicaktim burasi neresi abv

Are the lectures available on DVD or other media

Great

He means d of (t squared)- d of (x squared) right?.

THANK YOU

Plz provide the link lecture notes if there are

I love the way he is eating in all his lectures.

Burda ne arıyom ÖSYM senin yuzunden

I am coincidentally watching this on Susskind's birthday 2019.

The Great Physicists' Road Trip by Ms. Rachel C. Millison

Great physicists from the past decide to return to Earth for one last road-trip vacation to the coast together. They all appear on Earth on the designated evening. Heisenberg pulls up behind the wheel of a gigantic 1930's car, a huge grin on his face.
As they're getting in the car, Hubble looks up and says "What a wonderfully dark sky".
"Shouldn't be" responds Olbers.
"Always has been" says Hoyle.
"No, it hasn't" says Lemaitre.
"I knew that!" says an embarrassed Einstein.
Once they're all in, Teller says "Hey guys, this trip is going to be The Bomb!".
"Yeah, but why do I always have to organize?" asks Oppenheimer.
"Where exactly will we end up?" asks Kepler.
"That's impossible to predict" says Bohr.
"I just can't believe that's true" says Einstein.
Heisenberg punches the throttle and the old car roars off.
"Say - this thing sure accelerates" says Newton.
"I don't know, Isaac. It feels like gravity to me" smirks Einstein.

Later that night, as they are speeding down a country road, a police car catches up to them and pulls them over.[1]
"Do you know how fast you were going?" the cop asks. [1]
"No, but I know exactly where I am" Heisenberg replies. [1]
The cop says "You were doing 55 in a 35" [1]
Heisenberg throws up his hands and shouts "Great! Now I'm lost!" [1]
The cop thinks this is suspicious and orders him to pop open the trunk. He checks it out and says "Do you know you have a dead cat back here?" [1]
"We do now, asshole!" shouts Schrodinger. [1]
"I think it's time to split" says Everett.

"Say, how did you manage to spot us on such a dark night?" asks Hubble.
"I saw the light from your head lamps" says the cop.
"How fast was it going?" asks Michelson.
"That's simple addition" giggles Galileo.
"Not exactly" says Lorentz.
"Look here" says Heisenberg, "how do you know I was going that fast?"
"I clocked you over a measured distance" says the cop.
"How often?" asks Hertz.
"I disagree with your measurement, officer" interjects Einstein.
"Don't start tonight, Albert" says Bohr, shaking his head.
"What Herr Einstein is trying to say" continues Heisenberg, "is that time was running at a different rate for you than for us".
"WHAT!!!???" exclaims Newton.
"It's true" says Maxwell. "We're all famous scientists and, believe us, Herr Einstein has proved it, though it came as no surprise to me".
"Sounds complicated" responds the cop.
"I'll draw you a simple diagram" says Feynman.
Totally flummoxed, the cop lets them go with a warning. As he drives away, Doppler cocks his head and listens to the sound of the receding police car. "Gotta love that" he says.
"Amen" responds Hubble.

Returning to their car, Lord Kelvin remarks "Sure is warm tonight"
"Yep - lots of disorder" replies Boltzmann.
"In places you'd never expect" adds Hawking.
"I was lucky to get away with that" says Heisenberg. "Most cops think they're better than everyone else".
"Yes - I hate inequality" adds Bell.
"Though you were speeding" says Faraday to Heisenberg. "I carefully observed the needle creep from 35 to 55".
"Actually, it was jumping, Michael" replies Planck.
"Hey, Max" says Heisenberg, "If you loan me a tiny bit of money, I'll pay it back so quickly you'll never notice it was gone".

As they pile back into the car, Bohr says "See here - you must fill the seats in order - no empty spaces allowed. And stop interfering with each other!"
"Only one of you can sit next to me!" yells an agitated Pauli.
"Say, Werner - it's stuffy in here. Be a good chap and crack the window a bit" says Hawking.
"Sorry, Stephen. It can be all the way up or all the way down, but nowhere in between" replies Heisenberg.
"Hey guys - Albert and I just figured out a great shortcut. Only one bridge" announces Rosen.
"It will save us a lot of distance" says Einstein, "but it might get spooky".

Arriving at the beach the next morning, they hurry from the car and stand looking out over the ocean.
"Look at the wonderful waves" says Schrodinger.
"They don't look like waves to me" says Bohr.
Looking down at the fine sand, Dirac exclaims "Look at all the particles!"
"Now those look like waves" says De Broglie.
"This is great!" exclaims Feynman, rubbing his hands together. "Now, lets go meet some girls!"
"Let's delay" says Wheeler.
"We have to be discrete" warns Bohm.
"Girls? NEVER!" exclaims Newton.


1 Based on, and including the original, attributed to Rich Granger, engineer, Battelle.

This is about 12 years ahead of me, can someone dumb it down real quick?

Why am I here?
I’m in year 8 and got a C in science...

Chochwaa thirkaawaa hiii re? Gaanjaa pee kr bhooo hi kaa be?

Motkaa....takklaaa...bhaisaa.....mausaaa aur mauusiii dunno k baraati hau re....aur tu mauga hai tohar baraati naa niklega....pehchaan rhaa hai re chakkaa ke aulaad....😇 my words mean that u r a very good teacher sir......sala chakkwaa takalwaa...belchattaaa....badddii maar maarenge....smjhaa na be? Pehchaan rhaa h belmunndaa saalaa

No. No I’m not impressed at all. No. Weak.

does anybody knows the name of the textbook used in this course Special Relativity.

I have school tomorrow and I could not sleep and so I looked up lectures to make me bored and sleep, I accidentally learned something and staid up another like hour and a half

why are these students questioning simple math errors of the professor. x prime is bigger than x etc. this is the most simplest transformation that you can think of. why they questioning the professor for these slight errors. these students are stooopid

the students in stanford are asking really dumb questions. Log scale?