Relativity 104c: Special Relativity - Time Dilation and Length Contraction Geometry

0:00 Intro
3:14 Invariance, Covariance, Contravariance
7:28 Example Lorentz Transformation
13:29 Time Dilation
22:27 Length Contraction
27:35 Example: Muon Decay
30:28 Summary

[eigenchris]

Typo at the bottom of the slid eat 5:04. The last line should be x and y instead of t and x. Sorry for the copy+paste error.

[alapandas]

This is the best channel for learning relativity and tensor calculus.

[mobilephil]

The patience and clarity of your explanations is absolutely fantastic. Thanks for taking so much trouble and care with this.

[ultramadscientist]

I really like your approach of introducing galilean relativity in geometric, algebraic, and tensor formulations so that we not only keep using the same language all the way through but also have a very strong basis in translating between our three languages on the way. I know you said it'd make general relativity a little easier but it even made special relativity a little easier.

[killer]

I really appreciate your efforts to explain everything geometrically. This will surely make the introduction to general relativity a lot smoother.

[mot]

CLEAR, STEP-BY-STEP EXPLANATION WITH SUPERB GRAPHICS!!! GREAT JOB.

[JoeHynes]

you have helped me immensely, i have was in the navy and have worked various engineering related jobs for the past 24 years but have never actually sat in a college classroom. Thank you for your work!

[NicolasSchmidMusic]

I have just been watching 10 of your videos in a row. It is excellent! Everything is well structured, you understand the misconceptions a beginner could have. Thank you !

[leonardp]

12:20 this right here always confused the hell out of me. How can you scale with gamma back and forth and not stretch the coordinate system out infinitely in the process? Now
I get it. I've been actively trying to understand relativity for some time now, and this series is better than anything I've seen both in other youtube videos or physics textbooks. Thank you comrade.

[joeheafner]

Another excellent video. I will once again recommend this series to my physics students this semester.

[OhChrissake]

"So if we have this spacetime vector *S* connecting a sneeze event and a clap event, time dilation is just measuring this vector with different basis vectors and we'll get a different time component in each basis."

There is a beautiful economy to this 'spacetime separation vector' approach (an approach I have never seen done elsewhere).

[paulbizard]

Thank you Chris. I overviewed briefly Special Relativity as an engineering student long ago. And now that I'm retired and watching your videos, you are answering all my questions. This Minkowski space time diagram is a so powerful tool. LOL. Hope you win the Nobel asap. 😁

[vitrums]

22:09 a great image. It finally made the idea click for me. As soon as something is being observed moving relative to us (in this case it's Einsein chilling with the clocks in his hands, who seems to be in motion from our perspective while we drive a car), all observed unit time interval events (such as a full tick cycle of his clocks) happen in our reference frame every γ≥1 time units. Therefore, despite the fact Einstein himself is moving away from us with a great speed, from our perspective all the motions of his body and of the objects surrounding him appear in slow-mo.

[ShadowZZZ]

As a physics student I'd like to show my apprechiation here for your well explanation of einsteins special relativity, the deratavion of the equations, explaining time dilation & lenght contration on vector components.

[hazratprince]

Sir, I really appreciate your struggle
One of great teacher takes helping from ur channel,

[yongsikchu]

@26:59 I think the train in the car frame should be aligned along e_x tilda because it is in the moving frame at the simultanity .

[FakePhilospher]

good lord, you have crafted a masterpiece

[OhChrissake]

Note to self (17:25): Remember, from the car's point of view (i.e. frame) it (the car) remains in the same place as the sneeze, and it is Einstein who moves to the left before clapping (3.46 time units later, in the car's frame).

[Vkonto]

This is incredible ... The best explanation on YouTube for time dilation ..can you please add a video on twin paradox

[redbel]

This is very easy, but a lot of information for me to save all of this