Why were perpendicular arms crucial in the Michelson-Morley experiment?

[mk9898]

Why was it important that both arms were parallel and perpendicular to the rotation of the earth?

 

[DennisN]

Why was it important that both arms were parallel and perpendicular to the rotation of the earth?

Hi mk9898, do you know what the experiment was designed to detect?

 

[mk9898]

Of course...

 

[DennisN]

Of course...

Ok. A couple of more questions : Do you know how the experiment was designed to detect an aether? And do you know what interference is (i.e. interference of light/electromagnetic waves) and/or how an interferometer works?

 

[mk9898]

Can someone answer my question? It seems DennisN just wants to be superfluous and cheeky.

 

[DennisN]

Can someone answer my question?

Definitely.

It seems DennisN just wants to be superfluous and cheeky.

Not at all. I am doing my best to help out. You were very short in your first post, and also in your reply, so I am trying to understand what you know and don't know about the experiment. If I just tell you the answer to your question, the result may be that you learn less about the physics of this experiment.

 

[DrClaude]

I wouldn't have asked such a terse and direct question (like most people on this forum want) if I didn't already know about this experiment...

That's not true. See
https://www.physicsforums.com/insights/little-excuse-ask-question-cold/
Thread closed. You may only open a new thread on the same topic if you detail what you know about the MM experiment and what you are struggling to understand.