Recent content by jarvis

mmm I think I would cut the fat off of my steaks and chicken with a good knife rather that whacking it with a textbook... The reason an arrow cuts in the first place is the following. The arrow has a certain momentum based on its mass and velocity, and it maintains that momentum based on its...

Green functions are not confined to differential equations containing the Laplacian, they work under an arbitrary differential operator. The Green function is by definition the solution to a differential equation under application of a unit impulse source term. The beautiful thing about Green...

This is a very entertaining thread, in the funny nothing of consequence sort of way! :rolleyes: It has been like daytime television. I can read page one, then come back later and read page 6, and I have not missed a beat! Anecdotal arguments, lucky for us, are not sufficient to cease all...

I just make it up as I go Vanesch! :-p

There are electron beam welding/cutting machines commercially available at present. However, these need to be operated in a suitable vacuum environment. This is because the mean free path, i.e. the distance something will travel before it collides with something else, of electrons at typical...

My best guess follows:rolleyes:. CO2 gas and Nd:YAG lasers are probably the most commonly used for industrial cutting and processing. To answer your question it is important to understand what is happening in a laser cutting process. In order to make a "cut" in a piece of material I need...

What Griffiths does here is standard practice when integrating by parts, always look to eliminate the boundary term by physical argument, i.e. the potential due to some charge distribution vanishes at infinity. Like Meir said, the surface integral is evaluated only at the boudary of the system...

The first known demonstration of electrostatics as a tool of man was by Thales of Miletus (~600 B.C.), who demonstrated that amber could attract lightweight objects after being rubbed with cat fur. It was long thought that this was simply a material property of amber, but in 1600, Gilbert...

recomendation Charles A. Brau "Modern Problems in Classical Electrodynamics" This one follows the spirit of Landau's "The Classical Theory of Fields", developing electrodynamics in the framework of 4-vector formalism rather than the typical methodology of say, Jackson, where life is a...