Dielectrics and standing waves

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Discussion Overview

The discussion revolves around the effects of dielectrics on the number of modes for standing electromagnetic waves in a box. Participants explore how the presence of a dielectric influences the wavelength of electromagnetic waves within a metallic reflecting box, considering both theoretical and conceptual aspects.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants inquire about the specific effects of dielectrics on the number of modes for standing electromagnetic waves in a box.
  • There is a suggestion that dielectrics may not affect the null field value for standing waves at the boundaries, although this is presented as a personal hypothesis needing confirmation.
  • Questions arise regarding the interpretation of "the number of modes," with some participants seeking clarification on whether this refers to a finite number of modes or the number density per frequency interval.
  • One participant mentions that the presence of dielectrics could make the edges of the box "fuzzy," affecting the wavelengths that can fit inside the box.

Areas of Agreement / Disagreement

Participants express uncertainty about the effects of dielectrics on standing wave modes, with multiple competing views on how these effects manifest. The discussion remains unresolved regarding the specific implications of dielectrics on the number of modes and wavelengths.

Contextual Notes

Limitations include assumptions about idealized conditions and the need for further clarification on the definitions of modes and their density in the context of dielectrics.

gildomar
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How do dielectrics affect the number of modes for standing electromagnetic waves in a box?
 
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gildomar said:
How do dielectrics affect the number of modes for standing electromagnetic waves in a box?
What are your thoughts? How does the presence of a dielectric affect the wavelength of the EM in the metallic reflecting box?
 
berkeman said:
What are your thoughts? How does the presence of a dielectric affect the wavelength of the EM in the metallic reflecting box?
I suspect that it doesn't, since a dielectric shouldn't affect the null field value for standing waves at the boundaries. I just wanted to confirm if my thinking was right.
 
gildomar said:
How do dielectrics affect the number of modes for standing electromagnetic waves in a box?
What do you mean by "the number of"? Is there a finite number of modes? Or you mean the number density (per frequency interval, forexample)?
 
nasu said:
What do you mean by "the number of"? Is there a finite number of modes? Or you mean the number density (per frequency interval, forexample)?

What I mean is that I was reading that for an idealized box, that the waves have nodes at the edges of the box, but that when dielectrics are used, it can make the edge of the box "fuzzy" in regards to the wavelengths that can fit inside. I'm just trying to get a better handle on the how and why.
 

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