Recent content by weichi

So I think you are saying that we can assume that the D field is the same on each side. But that would imply that the E field outside the dielectric would be a constant independent of the dielectric constant. And I don't think that's right, because in the limit of a very large dielectric...

It wasn't actually a homework question, but I agree that it sounds like it could be one :smile:

Since no one has responded yet, I will give the reasoning I've come up with for the case of a linear dielectric. We know that the effect of the polarization will be to introduce a bound surface charge density on the surface of the dielectric. Instead of working with the D field and the free...

We have an infinite half-space filled with a dielectric. The other half-space is vacuum. We take a sheet of charge of density \sigma and place it on the surface of the dielectric. What are the D & E fields everywhere? We clearly have D_1 + D_2 = \sigma. But what other equation do we have? Can...

Easily? Can you elaborate? Or post a link to a paper which explains this?

I went through the same process a few years ago, and I will be receiving a masters in physics this May. I started school at age 35, so similar to you. 1. As Locrian and TMFKAN64 said, you are going to take a huge financial hit unless you can find a company to pay for school *and* pay you a...

I think there's an aspect of this question that is just semantics, but it's not completely semantics :smile: All (?) of the waves we have direct experience of are mechanical, like your rope example. Also sound waves, water waves. In these cases some material object(s) is *moving*, and we...

Wow, quite a coincidence - I just read chapter 3 of Stillwell, "Mathematics and Its History", which mentions this result! He says it was proved by Cauchy in 1813, with a "short" proof by Nathanson in 1987 (Proc Am Math Soc, 99, 22-24). good luck!

Do you mean "what side is positive and negative" in the real circuit, or what side should you choose + and - when solving the circuit? If the former - you can't tell until you solve the circuit! If the later - I always choose a direction for the current in each branch, voltage drops in the...

Pozar, Microwave Engineering, discusses these (for finite width). See also Jackson problem 8.3. Not sure of a treatment for infinite width, if that is what you mean.

I don't see why working in k-space would require tensors. I also don't think working in k-space would be helpful for this particular problem, but I admit I haven't given it a great deal of thought.

I didn't say anything about fuzzy :smile:! You would get the sum (superposition as DaleSpam said) of the EM wave and the "pre-existing" magnetic field. This is not the same as saying that the light would get "fuzzy. It means that if you put, say, a light detector in the region then it's...

But magnetic forces *don't* act on other magnetic forces. As V50 pointed out, they act on *charged particles*. In your magnet example, a better way to think about it is that the magnetic fields from the two magnets are added together, so that the total magnetic field is the sum of the two...

Yes, exactly! The direction (and location) of the current is always changing. Biot-Savart only applies to steady currents. Not sure what you mean about tensors, I don't see a use of tensors here. If you are stuck, why not post what you have so far? Both your solution approach and your...

Ben is of course correct - there *is* a current here. It would be a good exercise to calculate it! Note that this is, in a sense, a "baby" version of the problem you are asking about, but in this case you need to find a vector field who's *divergence* you know. But once you calculate the...