Recent content by sigma_

My question is the one you address in your first paragraph: The first derivative test is inherently intuitive. Slope is an intuitive geometrical concept. You are searching for this information contained within a function, not trying to eek out information about an unknown function L(x) using...

Background: I am an upper level undergraduate physics student who just completed a course in classical mechanics, concluding with Lagrangian Mechanics and Hamilton's Variational Principle. My professor gave a lecture on the material, and his explanation struck me as a truism. Essentially, he...

understand that, broadly speaking, Poynting's theorem is a statement of conservation of energy. There are many forms of the theorem, so I will simply give my current intuitive understanding of it in words: Energy density of a volume of current and charge decreases proportionally to work...

Homework Statement "In frame of reference S, an electron moving along the x-axis has energy 3mc2 and momentum magnitude √(8)mc Use the transformations of energy and momentum to find the energy and momentum magnitude observed in frame S′ moving with speed 4c/5 relative to S in the positive...

Thank you very much for your help!

Let's say, for instance, an LIH dielectric between the plates of a parallel plate capacitor.

So in the scenario I listed above, ##\mathbf D## and ##\mathbf E_0## are interchangable as long as a factor of ##\epsilon## is accounted for?

Got it. Thanks

Would you agree that distance is not arbitrary? Would you agree that velocity is not arbitrary? What quantity relates these two? Time increments are man-made. Time itself is not.

Before you get too caught up in your hating: http://en.wikipedia.org/wiki/Onagawa_Nuclear_Power_Plant#2011

I'm not sure any manmade container could contain a nuclear blast. The sheer amount of heat generated couldn't be handled by any static material. Some sort of flow shielding would be needed.

Why are plane waves said to be infinite in extent? Why can't a wave have one frequency without being infinite in its "domain"?

Thanks for the reply, Jano! We also know, however, that ∫D.dA = Qfenc so D has to somehow be related to the applied field, because it is the flux density of the free charge, and typically free charge is what we control, and create (apply) fields with. I think maybe my interpretation of D is...

I agree with you, it's by far the best way to learn, but that can be cost prohibitive to some people, especially if he's young. We don't want PF to come off as unwilling to help, if that's the case.

E would represent all the energy due to all the mass in the universe, not the total energy in the universe. Hope that makes sense