Experimental evidence that Snell's law is correct

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Discussion Overview

The discussion centers around the search for direct experimental evidence supporting Snell's law, particularly regarding the refraction of different spectral colors (RGB) when passing through a prism. Participants explore the nature of evidence and the implications of Snell's law in various contexts, including practical applications and experimental observations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about sources for direct experimental evidence of Snell's law for RGB colors.
  • Another participant suggests that the experiment is trivial and commonly performed, indicating that refractive indices for various glasses are well-documented.
  • A clarification is made regarding the term "direct" in the context of experimental evidence, emphasizing the need for evidence of color-specific refraction through a prism.
  • A later reply argues that the ability to see under near-monochromatic light serves as evidence for Snell's law's validity, citing practical examples such as refractive telescopes focusing light from emission nebulas.

Areas of Agreement / Disagreement

Participants express differing views on what constitutes sufficient evidence for Snell's law, with some asserting that practical observations are adequate while others seek more specific experimental data. The discussion remains unresolved regarding the definition and sources of "direct" experimental evidence.

Contextual Notes

Participants have not reached a consensus on the type of evidence required to support Snell's law, and there are varying interpretations of what constitutes "direct" experimental evidence.

goniahedron
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Where can I find direct experimental evidence that Snell's law is correct for at least three of the typical spectral colours (say RGB). Thank you.
 
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May I ask why exactly you are asking? This is a trivial exercise performed in many places, including my undergrad labs last year. If I still had my lab notebook I could show you the data.

In any case, I'm not exactly sure what you're looking for. The refractive index for most of the visual spectrum is known for essentially every type of glass in existence. You should be able to find the appropriate values in many places. Is that what you're looking for?
 
Drakkith said:
May I ask why exactly you are asking? This is a trivial exercise performed in many places, including my undergrad labs last year. If I still had my lab notebook I could show you the data.

In any case, I'm not exactly sure what you're looking for. The refractive index for most of the visual spectrum is known for essentially every type of glass in existence. You should be able to find the appropriate values in many places. Is that what you're looking for?

I apologise if my question was not clear enough. It's only that by my adding of the term "direct" to "experimental evidence" led me to assume otherwise. In any case, allow me to rephrase my original question:

Where can I find experimental evidence that Snell's law is correct about the different degree of refraction that each colour experiences when passing through a prism (medium) beside that in which the purporting experiments use the colours dispersed from a beam of white light to extrapolate the premise.
 
goniahedron said:
Where can I find experimental evidence that Snell's law is correct about the different degree of refraction that each colour experiences when passing through a prism (medium) beside that in which the purporting experiments use the colours dispersed from a beam of white light to extrapolate the premise.

The fact that you can see anything under a near-monochromatic light source should be evidence enough. If Snell's law wasn't correct for non-white light sources, your eyes wouldn't focus the light correctly. Another example is the large number of images taken through refractive telescopes of emission nebulas (do a google image search for "emission nebula". A large percentage of those images were taken through refractive telescopes). They emit light predominantly in a handful of spectral lines. Again, if Snell's law wasn't correct, then these telescopes would not focus the light correctly and we would have to shape the lenses differently depending on which light sources we planned to observe.
 

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