How does LIGO detect gravitational waves?

Overview of the math behind the core optical technologies in the Advanced LIGO gravitational wave detectors, including Michelson and Fabry-Perot interferometers.
Intro 0:00
Gravitational waves interaction with spacetime 2:28
Basics of laser beams and mirror 5:18
Fabry Perot interferometer 10:31
Michelson interferometer 18:36
Fabry Perot Michelson interferometer 22:53

Thanks to 3blue1brown the manim community for making this video possible.

[SK-cbwz]

5:54 this is a very good demonstration, great ❤

[danksta]

Very cool looking forward to your LISA video

Wow just, wow..
The way you explain it.

[alanweinstein]

Required viewing by our grad students! And yes, more videos like this!

[rakinmunim]

Great Video. I still don't understand it, but I'm sure once I have fully analyzed it, I will have gained great insight. Thank you!

[jagdishchandras]

Wonderfully explained ! Sharing with grad students.

[SergioNieCas]

This video is great, thank you very much for the expaination ❤

[luckyshadowtux]

If Mr. Robot was into physics. But seriously, beautiful video.

[sergniko]

Very nice and understandable explanation. Thanks for you time!

[arun_kishor]

Thank You! Please, more videos like this !

[ondtsn]

Gravitational waves is not only cause of merging of two black holes but contrary a black hole inside of a galaxy always propogates continous gravitational waves into the galaxy.Ref to :Beyond The Light Barrier.

[hunterabdo]

For understand Time is inside the detector gravitationel waves because is special realtionship between gravitationel waves and time

[pritamgaming]

Loved ❤ this video. We want more Physics videos in similar style of 3blue1brown in Mathematics. If there already exists some of those kind of Physics videos please let me know😀.

[TechEsq]

"Now *that* is a highly performing cavity." :D :D :D

[cstalt]

Excellent video! One question, you note 1KW transmission power but my understanding is that LIGO uses a ~1MW laser. Just wondering what that discrepancy is about.

[SK-cbwz]

4:24 I'm still struggling to understand what that reference green line mesh is.

[nibydcgrshbdcjd]

EM wave is moving backwards through the input mode cleaner

[texsetter]

thanks!
two questions:
- what is the meaning of the 3 small mirrors on the left?
- the gravitational waves modify not only the space but also the time. How does this affects the instruments?

[themathsdude]

hi dude, litte fleedback on the fly
sound is not loud enough i think, you should try to level it with your good music !
do theses h values have units ? when you talk about them being small
i think you should have added units and reminded of how a mirror has a tau and r number associated, in which they affect the refected and transmitted wave, not to go in the derivation but just quick reminder on the side, which are complex numbers i guess ? don't remember
maybe you should add some text alongside animations, i mean explicitly write the nature of your notations of waves and every letter of screen
i'll go back to my physics undergraduate course and come back to this video
very hard work and very good visual quality, kudos for that !!!

[akta]

Why the laser wave lenghy is not changed while the gravitation wave is passing throught the space ?
If the gravitation wave affects L it should affect the laser wave length as well.