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Visual tour of classical electromagnetism

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11–15 of 15 posts

Re: Visual tour of classical electromagnetism

#11

One early misconception I had about EM was that there were discrete 'lines' of force. I guess this either arose from iron filings experiments or from the way the diagrams of fields are (perhaps unavoidably) drawn. But now I know the fields are continuous.

> But now I know the fields are continuous.

Wait 'til you hear of quantum electrodynamics ;)

Re: Visual tour of classical electromagnetism

#12

One early misconception I had about EM was that there were discrete 'lines' of force. I guess this either arose from iron filings experiments or from the way the diagrams of fields are (perhaps unavoidably) drawn. But now I know the fields are continuous.

I'm still confused by the notion of line/field/flux density. That said, I found a few books to read about that.

Re: Visual tour of classical electromagnetism

#13

One early misconception I had about EM was that there were discrete 'lines' of force. I guess this either arose from iron filings experiments or from the way the diagrams of fields are (perhaps unavoidably) drawn. But now I know the fields are continuous.

> But now I know the fields are continuous. Wait 'til you hear of quantum electrodynamics ;)

To be fair, this is about classical electromagnetism.

What is annoying though, it is the pervasive practice according to which some authors completely ignore H ("intensity of the magnetic field") while others pretend to know nothing (and nor should their students) about B ("magnetic induction").

Somewhat less annoyingly, the teachers of electromagnetism rarely introduce the students to the formulation in terms of differential forms, which many consider a better, more intuitive way of doing electrodynamics compared to vector analysis (which student still should learn, of course).

Re: Visual tour of classical electromagnetism

#14
Cool!

Nearly all my comments so far are about books but Jackson's Classical Electrodynamics provided a turning point in my understanding of E&M.... and took over a year (of pain) to get through.

On the other end of the 'spectrum', Griffiths Intro to Electrodynamics is extremely readable and just as good.

Re: Visual tour of classical electromagnetism

#15

One early misconception I had about EM was that there were discrete 'lines' of force. I guess this either arose from iron filings experiments or from the way the diagrams of fields are (perhaps unavoidably) drawn. But now I know the fields are continuous.

I'm still confused by the notion of line/field/flux density. That said, I found a few books to read about that.

This may be a good explanation: https://www.uio.no/studier/emner/matnat/fys/FYS4160/v08/unde...
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