Interpreting light as Maxwell's EM wave

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Discussion Overview

The discussion centers around the interpretation of light as an electromagnetic wave according to Maxwell's equations. Participants explore different representations of light waves, questioning the accuracy of popular depictions and discussing the complexities involved in visualizing electromagnetic fields.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants express difficulty in visualizing light as the standard blue and red electromagnetic wave, suggesting that light may appear more chaotic in reality.
  • Others argue that understanding the solutions to Maxwell's equations is essential for accurate representation and that visualizations should be derived from mathematical software.
  • A participant mentions the EM field as a 10-dimensional object, which prompts questions and challenges regarding the interpretation of field degrees of freedom.
  • There is a suggestion that the first image representing EM waves should not be taken literally, as it may not accurately reflect the nature of light.
  • Some participants emphasize the importance of personal engagement in plotting and understanding electromagnetic waves rather than relying on pre-made visualizations.
  • Questions arise about the accessibility of mathematical software for non-experts and whether such tools can provide a true representation of EM waves.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best way to visualize electromagnetic waves or the interpretation of the dimensionality of the EM field. Multiple competing views remain regarding the accuracy of different representations and the role of mathematical software in understanding these concepts.

Contextual Notes

There are unresolved questions about the assumptions underlying the representations of EM waves and the complexity of visualizing higher-dimensional fields in lower-dimensional spaces.

  • #61
vanhees71 said:
It's true for plane-wave modes

Well, I'm implicitly in the high-school mode, so I can't say anything about general case since I don't remember much about that (I took upper level classical electrodynamics course in 2012...).
 
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  • #62
wonderingchicken said:
But the electric field and magnetic field for each point in space doesn’t have to be necessarily perpendicular, correct? For example, like in this picture the electric field and magnetic field is not perpendicular http://physics.thick.jp/Experimental_Physics/Section1/figures/fig1-4-2_en.png
They are perpendicular.

Your question has already been answered. In the far field (aka a EM wave) they are perpendicular. In the near field they do not need to be perpendicular.

Why are you still re-asking this question more than 20 posts later?
 
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  • #63
Ibix said:
A "skeptical" response from @wonderingchicken, so I will repeat a question I asked in #50: you have posted a lot of diagrams of electric fields that look like this:
View attachment 325468
Do you think that they are meant to imply anything about the electric field anywhere except exactly on the zero-width black line?
The axis is imaginary, correct? We can put the axis anywhere whether on top of the field, below, etc.

I have my own opinions regarding the electric and magnetic fields but this is not the "right" place to say anything about it because this entire forum is almost like a cult. Sorry for the honesty. o_O
 
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  • #64
wonderingchicken said:
The axis is imaginary, correct? We can put the axis anywhere whether on top of the field, below, etc.
This shows a pretty big misunderstanding of the whole concept here, as well as a misunderstanding of the question asked. I am going to repeat my original recommendation that you get a computer algebra software package, write a known solution, and try plotting it. That exercise will be more beneficial for you than another 20 posts asking the same questions again.

wonderingchicken said:
this entire forum is almost like a cult. Sorry for the honesty.
Sorry for the thread ban, honesty is not a good justification for insults.

@ other participants, you may respond further if you wish but be aware that the OP will be unable to reply here
 
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  • #65
wonderingchicken said:
I have my own opinions regarding the electric and magnetic fields

Opinions based on what? Lack of knowledge? You have shown in this and other threads that you are not here to learn. You just waste our time.

Dale said:
@ other participants, you may respond further if you wish but be aware that the OP will be unable to reply here

So is there any point in keeping this thread open? @wonderingchicken reply will be with "skeptical", as usual...
 
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  • #66
wonderingchicken said:
The axis is imaginary, correct? We can put the axis anywhere whether on top of the field, below, etc.
The axis is the thing in the diagram with the strongest claim to being real. The red line is a visualisation of the values of the electric field on that axis and only on that axis, nowhere else. It is no more real than a graph of economic growth - do you think a graph of a rising share price means that there's actually a set of hydraulic jacks somewhere lifting the price up off the ground?

The black line at least has the virtue of representing a set of points in a straight line by a set of (near) points in a straight line.
wonderingchicken said:
this entire forum is almost like a cult
If I stand on Earth and drop a ball then it will fall. Would you agree? Would anybody disagree? Are we all part of a cult of gravity, then? Or are we just dealing with reality?

We are trying to describe a shared understanding of a well-studied phenomenon in this thread, an understanding that we routinely use to design and build devices like the one you are reading this on. Dismissing it as a "cult" is just as daft as dismissing gravity as a cult. It just takes a bit more work to understand what we're describing because the details are not in your every day experience.
 
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