The Michelson interferometer

How a Michelson works, a derivation of the interference condition and how it is used to catch gravitational waves.
Fixed typos in derivation 5/10/22.

[@kingcookie3920]

It seems counterintuitive to me that there's destructive interference when the path length difference is zero.
Shouldn't the waves cancel each other out at a path length difference of λ/2?

[@rinashahril27]

Makes studying easier thanks!!

[@bormell119]

Very helpful explanation! Thanks!

[@flyingbirds6794]

thank you very much