Why is speed of light the same (c) in all frames? (An intuitive explanation)

Why is the speed of light the same in all reference frames? Let's rediscover the thought experiments that led Einstein to his special theory of relativity

Chapters:
00:00 Introduction
01:15 1/3 Detect motion with particles? (Thought experiment)
04:01 Inertia doesn't allow detecting constant velocity motion
06:18 2/3 Detect motion with waves? (Thought experiment)
09:18 Medium doesn't allow detecting constant velocity motion
10:15 Constant velocity motion is RELATIVE!
11:02 3/3 Detect motion with light? (Thought experiment)
13:12 Does light break relativity?
13:46 Michelson & Morley's experiment (oversimplified)
14:20 The logical conclusion - Speed of light is same in all frames
15:32 Discovering time dilation & length contraction
19:59 Summary

[SPDLand]

Never met a guy that had so much conversations with Einstein. And than sharing it with us even. Thanks Mahesh!

[deriznohappehquite]

“Your honor, I was at rest, the schoolchildren were coming at me at 80 mph.”

[DrMikeE]

Did not understand this as an undergrad over a half-century ago. Went on to get PhD in math a few years later and had a 45-year career as a math professor, never really understanding this.... And now? This presentation was Magnificent! Thank you so much! OH, AND YES! PLEASE DO SHOW THE ALGEBRA/ GEOMETRY IN A FUTURE VIDEO!

[TouchingClothProd]

You are the only person who has ever explained this in a way that actually makes sense to me. TY

[sauravpatgiri]

This is the best explanation I have ever seen. Simplified and crystal clear.

[yonip]

I watched dozens of videos about relativity and this was by FAR the best. Please make more exactly like this

[jyotishman]

As a teacher, I always find it difficult to simplify the topic . But once I could prepare the topic like you did in the video, my job becomes easier.

[brijeshpatel]

This is why Einstein said "Imagination is more important than knowledge". I'm proud of myself!! 🤓Today, for the first time in my life, I imagined outcomes of special theory of relativity. Thanks Mahesh. Please do the next part of the video.

[karlfreiha]

indians helping random youtubers is stepping up from voice and notepad text tutorials to this masterpiece. sir u answered the questions i had been looking for in such an elegant way i salute you

[randomutubr]

We need to get this guy to 1m subs. I watch a ton of science communication channels, all the heavy hitters, and this guy far and away does the best job of walking through these problems in an intuitive way.

[dr.z]

As a biology PhD who is trying to learn more physics, I felt mind blown by your derivation! Keep it up!

[PaulThronson]

As a historian with an interest in science, your videos are great. Thank you for the top notch content

[hicsuntdracone]

I never really truly grasp the true meaning of the special relativity, until i watched your video. Your style of teaching is really intuitive and easy to follow, even on complex topics. Love your work, and keep doing what you're doing, cheers.

[citizenat]

Nobody's ever explained that better than this, science needs more people like you, my friend.

[bobstanley]

One of the best physics communicators on YouTube!

[usaturnuranus]

I've sat here for well over an hour this morning watching and rewatching this video, and for the first time I feel like I'm actually beginning to gain a decent layman's understanding of the characteristics and vagaries of the behavior of light and electromagnetic radiation in general. I really appreciate the presentation, as my son and I (both adults) really enjoy discussing physics related subjects. As a curious layman I am thankful for the easily accessible style you provide. Well done.

[Sympanet]

I don’t remember how I found you but this is quickly becoming one of my favorite channels

[joseph_soseph]

I always thought that I had a pretty good grasp on special relativity, but your explanation of the complete history of this theory really deepened my understanding a lot more. Thank you, beautiful video.

[HoneyBadgerLikesYou]

This was incredible. I really love it when educators walk us through the logic of HOW we arrived at our conclusions, including all the incorrect assumptions we made and discarded along the way. It really helps round out our understanding and motivation. This was really well made. Thanks so much

[aneeshchauhan]

What an awesome video! Since high school I have not been able to capture or understand this intuition well, and 26 years later you have succeeded. Thanks so much.

I think one of the MAIN reason students can't get the intuition is that any attempt to explain relativity starts with "person in a vehicle" vs the "person standing" metaphor. That is such a counterintuitive example. Human experience of a car or train or a plane is that of a transportation machine. They move in all of human experience. To put us in the shoes of the person inside the car, and then thinking that the person standing is the one actually moving, is extremely challenging and goes against our experience of world.

I think educators should discard this example. The relative motion perspective that helped me is: Imagine two infinite escalators moving at constant velocity in opposite directions, next to each other (They don't wobble, or make sound, there are no walls, nothing to refer their motion). There is a person standing on each, and these persons have no way to tell if they are moving. Their experience is that of standing on an infinite stair. And then they cross each other. Person 1 perceives that Person 2 is moving, while Person 2 perceives that Person 1 is moving. Neither is able to tell if they are themselves moving.

Surely not the best example, but to my simple mind this example helps me more than the person in a car metaphor.