Recent content by novop

Great. Thanks so much.

Try operating both on a test wave function.

Homework Statement I need to prove that, <p'|\hat{x}p> = i\hbar\frac{d}{dp'}\delta{p-p'} i.e. find the position operator in the momentum basis p for p'... It's easy to prove that <x'|\hat{x}x> = <\hat{x}x'|x> = x'<x'|x> = x'\delta{x-x'} (position operator in position basis for x') since I...

Homework Statement Homework Equations The Attempt at a Solution The issue I'm having here is that the problem should be able to be done rather quickly. I can see how to solve for <H> using the operator, but there's a quick way that I'm not picking up on. I thought about solving <H> = <p^2> /...

All radiation. The screen just prevents all radiation but x-rays from passing through. I didn't base the emission of any radiation on what it is absorbing, I based it on the temperature. On that note, I think I see my mistake; there's no reason for me to require that the blackbody stays at...

Let's say there's a perfect blackbody inside a box (at room temperature) composed of material such that only x-rays are able to enter and leave. If the absorption and emission of the x-rays weren't the same, the box would heat up above room temperature, and this would contradict thermodynamics...

So a guy walks into a quantum cafe and asks for a coffee with half a sugar in it...

My friend has a cottage up in northern Quebec and it's a regular occurrence that he witnesses deers passed out from eating semi-fermented apples in his back yard!

Homework Statement My question is, why, when changing the variable from "v" to "lambda", does the d\lambda need to be included? Why can't a simple substitution c = v * lambda do the trick?

Thanks to both of you, makes sense.

So the wave-form of that particular particle only begins again, and evolves according to the Schrödinger equation, right after a measurement "ends"?

Homework Statement If x is the position of a particle then the expectation value of x, <x> is : (I got lazy and just copied an image from Wiki, just pretend <x> is on the lhs of the eqn) When Griffith derives an expression for d<x> / dt, he uses the fact that dx/dt is zero, since "the wave...

bump ^.^

I looked at it, and couldn't find any decisive answers.

Hi all, I understand that there are several solutions to Einsteins equations that consist of a rotating universe. I have a few questions. If the universe is composed of everything that exists, how can the universe rotate in the absence of space, since all space is contained within the universe...