Importance of Electrodynamics

[Stratosphere]

How important is classical electrodynamics to a good understanding of physics? Why should I bother to learn it if it has been replaced by QED? Also what are some good books for classical ED if It is in fact important to learn it?

[Klockan3]

Why is it important to learn Newtonian mechanics when you have relativistic quantum mechanics?

[fasterthanjoao]

Very important because, for most situations, it works extremely well (and there is no need to spend time taking quantum effects into account when you're looking at things dozens of orders of magnitude away from where they might be significant. That would be over-complicating the problem). Also, it gives one a usable, accessible framework with which to think about electrodynamical problems. The quantum world is strange and, if possible, I avoid it. :smile:

Griffiths was the book I used, and I liked it.

[ZapperZ]

How important is classical electrodynamics to a good understanding of physics? Why should I bother to learn it if it has been replaced by QED? Also what are some good books for classical ED if It is in fact important to learn it?

Look at your world. Roughly what percentage of your world do you have to drop classical E&M and invoke QED because the latter is necessary? Do you think we used QED to make sure the material, such as the semiconductor, in your modern electronics to work? Or what about the design of particle accelerators, some of which were used to verify the validity of QED and other parts of the Standard Model? Do you think they actually used QED to design those RF cavities and model the beam dynamics?

Skip classical E&M, and you're missing 99.99% of EM interaction physics. Not only that, you'll fail miserably in graduate school.

Zz.

[Stratosphere]

Look at your world. Roughly what percentage of your world do you have to drop classical E&M and invoke QED because the latter is necessary? Do you think we used QED to make sure the material, such as the semiconductor, in your modern electronics to work? Or what about the design of particle accelerators, some of which were used to verify the validity of QED and other parts of the Standard Model? Do you think they actually used QED to design those RF cavities and model the beam dynamics?

Skip classical E&M, and you're missing 99.99% of EM interaction physics. Not only that, you'll fail miserably in graduate school.

Zz.

Ah, ok, I see now. So what books do you think would be good for classical ED? Besides the expensive David J. Griffiths textbooks. Also would it be better to study ED before QM? Or would it be ok to study QM first? (I'd of posted this part in the science book discussion but I don't want to make another thread.

[Andy Resnick]

How important is classical electrodynamics to a good understanding of physics? Why should I bother to learn it if it has been replaced by QED? Also what are some good books for classical ED if It is in fact important to learn it?

In addition to the other good reasons mentioned, classical E&M is a classical field theory, and so shares the same formalism as continuum mechanics.