Recent content by nnnm4

BUT, there is a note of technical importance. Exponentials are useful in representing real wave-like solution mainly if those solutions are of a linear equation of motion.

The latter. It is to move the atomically-sharp tip across the sample view, which is on the order of hundreds of square nanometers (in a fine-scan scheme).

Okay that clears it up. They are talking about the equivalence between mass and energy that comes out of relativity. There is no analogous equivalence for charge.

Phil Anderson?

You're right. Write down the initial state, and then the time-dependent wave function, plug it into the Schrödinger Equation, it make sure it holds identically.

Thanks Andrew, cleared it right up.

Sorry, put this in the wrong section, please feel free to move it.

Dick is of course correct, and sin^2(p) isn't even the relevant function here. The Fourier integral is trivial and you should do it out.

The idea is that basically that the new eigenstates of the perturbed hamiltonian can be described by a series of eigenkets of the original unperturbed hamiltonian. However, you can't in general get the exact eigenstates of the new hamiltonian just approximations (the series). The old...

I expect it has something to do with the last step not being reversible.

Consider a resistor with current running through it for some time in a constant temperature bath. I understand that the change in entropy of the resistor is zero because there is no change between the initial and final thermodynamic state. However, I am trying to come up with a reversible...

You're basically right. The Fourier transform of the dirac delta will give a single momentum wave (an exponential with an imaginary argument), and the question as to whether it's normalizable is equivalent to asking whether it is square-integrable.

When you solve the Schrödinger Equation for a particular potential, you sometimes get different states that have the same energy. For example consider a particle in a 3D box. The energy is labeled by 3 quantum numbers (nx, ny, nz). The 3 numbers are equivalent so (2 1 1), (1 2 1), and (1 1 2)...

The way photon's behave is described by quantum electrodynamics. The point that ZapperZ is trying to convey is that this is the correct description of all phenomena, that is QED. Now, classically we always observe light propagating as a wave. Where does this come from? There are certain...

Nice, I'm glad you found a good reference. Anyway, the way I see it there is no distinction between whether H or S is more real. Neither picture, as you pointed out, makes any difference when one considers only observable quantities, i.e. the matrix elements of the operator under question...