I Speed of light in ether

Hi people!

May be this could be an historical question.
Before Einstein, it is suppoused that speed of light in ether is always the same, I´m right?
I mean, if observer O is at rest respect ether and observer O´ is moving respect ether and O´ send a photon to O, the speed at wich that photon arrives O (measured by O) is c cause, as I said, O is at rest respect ether? That is that the speed of O´, the source of the photon, must not be added to c.

Thanks for comment.
 

Nugatory

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If you're going to talk about what physicist believed before 1905 you will have to pretend that you never heard the word 'photon".... but you can substitute the more appropriate phrases "flash of light" or "light signal" and your question still works.

And with that correction the answer is "yes". However, this answer is inconsistent with the negative result of Michelson-Morley experiments, and that's how we ended up where we are.
 
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Thanks Nugatory! :-)
 
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Before Einstein, it is suppoused that speed of light in ether is always the same, I´m right?
According to the classical ether theory the speed of light was always the same in the rest frame of the ether (in absence of matter).
According to Maxwell the speed of light was the same in every frame of reference (again in absence of matter).
 
"According to Maxwell the speed of light was the same in every frame of reference (again in absence of matter)."
Good point!
Thanks DrStupid!
 

Nugatory

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Mentor's note: Several off-topic posts about the Lorentz ether theory have been removed from this thread. Despite sharing the word "ether", this is a substantially different theory (not falsified by Michelson-Morley experiments) than historical ether theory that the original poster was asking about.

Even if it were on topic in this thread, we generally do not allow discussion of the LET: https://www.physicsforums.com/insights/pfs-policy-on-lorentz-ether-theory-and-block-universe/
 
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According to Maxwell the speed of light was the same in every frame of reference (again in absence of matter).
Does that mean everything is at rest with respect to a flash of light or light signal?
 

Ibix

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Does that mean everything is at rest with respect to a flash of light or light signal?
No. It turns out to mean (coupled with the principle of relativity) that there is no such thing as "with respect to light". You can't define a frame where light is at rest.
 
Mentor's note: Several off-topic posts about the Lorentz ether theory have been removed from this thread. Despite sharing the word "ether", this is a substantially different theory (not falsified by Michelson-Morley experiments) than historical ether theory that the original poster was asking about.

Even if it were on topic in this thread, we generally do not allow discussion of the LET: https://www.physicsforums.com/insights/pfs-policy-on-lorentz-ether-theory-and-block-universe/
The reason I asked about it is cause in our class we have a first practice that ask we what previous to Einstein physics thought about some things and then in following practices we must found what after Einstein physics thinks about the same things.
 
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The reason I asked about it is cause in our class we have a first practice that ask we what previous to Einstein physics thought about some things and then in following practices we must found what after Einstein physics thinks about the same things.
There is some discussion on the history leading up to Special Relativity in this chapter of this book.
 
Thanks!
 

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