I never understood why speed of light is a constant (c)... until now!
inv.nadeko.net
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

This video is a bit older now (over one year), but I just found about it. And I want to share it here, because it was very well explained, without boring stock videos or background music. It’s just like a teacher would teach you, but with some enthusiasm behind it. I enjoy his videos so far.

Video description:

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
  • Pete Hahnloser@beehaw.org
    0·
    7 days ago

    Thank you for sharing this! I had something of a vague notion of how relativity works, but this was incredibly helpful in terms of nailing down why light is unaffected by the observer’s frame. I knew of the popular concept of the luminous aether at the turn of the 20th century, but never how it was debunked. Definitely subscribed, and now off to watch the explanation of how we then arrive at E=mc2.

    • thingsiplay@beehaw.orgOP
      0·
      7 days ago

      Exactly me too, lol. I was also confused about the aether, because I knew it was wrong but not why. Currently watching his explanation about how he arrive at E=mc2 right now (paused the video to link here). Not sure if this is the video you meant, but in case not I highly recommend this one too: I never understood why light has ENERGY but NO MASS… until now! - YouTube | Invidious

      • Pete Hahnloser@beehaw.org
        0·
        7 days ago

        Learning about this channel is seriously the best thing that’s happened since the election! I’ve just moved onto that video as well, but because of the algorithm, not your latest suggestion.