Why we rotate Michelson Morley Interferometer Apparatus by 90 degree

With the help of Michelson Morley Interferometer simulation I have tried to explain these basic concepts….
Rotation of Interferometer
Michelson Morley experiment
Semisilvered glass plate role
distance of two mirrors from semi silvered glass plate and its effect
time difference between two rays
path difference between two rays and Interference pattern
circular fringes
aether medium
ether medium properties
change in speed of light
change in fringe shift is due to change in path
path difference opposite at 90 degree from initial case.

If you like the video please like and share and suggest me topic of your interest.

Dr Sushil Kumar

Dr. Sushil Kumar, a physicist, an eminent researcher and a teacher for the benefit of students and fellow physicists alike. Apni Physics is an effort to create a better platform and also to help the students to be able to have content at their hands whenever they want, online. Dr. Sushil continues to upload his lectures and post articles about latest researches in physics, academic, physics education, and also lessons about daily life and how physics define every aspect of our everyday movement and life.

One thought on “Why we rotate Michelson Morley Interferometer Apparatus by 90 degree

  • 2018-10-03T08:46:04+00:00 at 2018-10-03T08:46:04+00:00

    MM experiment (done in air)

    I found a word “extinction” in a book Special Relativity by French, A.P. 1968. It’s written as follows (original text ; quoted from “Google book” ; in 5-2). “Thus, for example, with visible light, a thickness of about 10-5cm of glass or 0.1mm of air at atmospheric pressure is almost enough to erase any possible memory, as it were, of the motion of the original source” (10-5cm is 0.0001mm). What ?? If it is so (from frequency or from wavelength, “memory” is not erased), the result of MM experiment is only natural.

    Also, I found a book Theory of Relativity by Pauli, W 1958. In it, it is written as follows (quoted from English version ; in 1-6). “Rather should one say that ifor an observer moving with medium, light is propagated as usual with velocity c/n in all directions”. Extinction will ensure it. Also it seems to be the “very and true explanation” for MM experiment !!

    Then, how about the experiment done in vacuum ? The emission theory seems to be promising.


    Sorry, I cannot receive E-mail. I do not have PC.

Leave a Reply