Experimental investigation of c in electric & magnetic fields

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Discussion Overview

The discussion revolves around the speed of light in the presence of electric and magnetic fields, specifically focusing on the concept of birefringence as presented in a research article. Participants seek clarification on the implications of certain statements made in the article regarding experimental results and their relation to theoretical predictions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about the meaning of "birefringence with 0 n <" as mentioned in the article, seeking clarification on the notation used.
  • Another participant corrects the notation to "delta n < 0" and questions what this implies about the speed of light.
  • A request is made for a link to the paper and specific clarification on the section that is confusing.
  • Participants discuss the implications of a negative birefringence value and its contradiction with theoretical predictions, noting that it raises questions about the reliability of the experimental results.
  • One participant acknowledges their lack of knowledge to answer questions about the negative value's significance in the context of birefringence.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the implications of the negative birefringence value, and multiple viewpoints regarding its significance and relation to the speed of light remain unresolved.

Contextual Notes

There are limitations in understanding the experimental setup and the definitions of terms used, as well as the potential for unresolved mathematical steps in the discussion of birefringence.

mpolo
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I have been researching a question I have concerning the speed of light in magnetic AND electric fields. I came across an article in arvix but could not quite understand what they were saying. I am not a scientist I am just curious. There was a statement in which was shrouded in a strange nomenclature. Can someone please decipher what they are saying. They said, "In the experimental setup described there, this would mean a birefringence with 0 n (small triangle which I think means delta) <.
Sorry that I could not find the delta symbol. This experiment was referring to measuring the speed of light in a magnetic field and in a vacuum.
What does 0 n small triangle followed by a less than sign mean?
 
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Nidum said:
> click on the ∑ symbol in the menu bar at top of text entry box .
I need to make a correction to the formula. it is that the birefringence is delta n < 0 What are they saying about the speed of light here? This is confusing. Thanks for the help.
 
mpolo said:
I came across an article in arvix but could not quite understand what they were saying.
Can you post a link the the paper and direct us to the part you are not understanding?
mpolo said:
the birefringence is delta n < 0
∇n < 0 would imply what, given the Wikipedia definition of birefringence...

https://en.wikipedia.org/wiki/Birefringence
∇n = n_e - n_o
 
The paragraph number 2.
I need to have this spoken to me in payments terms. It looks to me as if the experiment is supposed to yield a positive value but the person or lab measured a negative value. How does this relate to the speed of light.
 
Sorry I am on a trip and using a cell phone. In the paragraph above I meant laymens terms not payment terms.
 
Yes typed it wrong. Your link is proper. Why is the negative value a problem concerning birefringence. Does anyone know?
 
mpolo said:
Yes typed it wrong. Your link is proper. Why is the negative value a problem concerning birefringence. Does anyone know?

To quote from the paper so others can see:
In the experimental setup described there, this would mean a
birefringence with ∆ <n 0 . The problem is, that the result of this experiment is in clear contradiction
with the theoretical predictions mentioned above, and furthermore it shows some artefacts
[Lam 07] which make the probability of a real result rather uncertain.

I confess that I don't have the knowledge to answer your question. :cry:
 

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