Recent content by student85

Thanks for your input. A follow-up question... Supposing we have this single-photon gun, what would happen if we do the famous Young (double slit) experiment using this gun as the source? Imagine we point the gun straight into the middle of the two holes and we shoot one photon. What would we...

Hi. I've been wondering if it is possible to have a "gun" that shoots one photon at a time. Does it exist already? If it doesn't, what are the technological limitations that prevent its production? Can you actually build/get one easily or is it so high-tech that only advanced labs have them...

So it is zero then?

I don't think that's what he meant, and I think some other people are misreading too. I think what he means is that his father has already got a down-to-earth project that will likely earn him some money. But he is thinking of using that money to develop his magnetic motor invention afterward. I...

No relativists here? :S

Hi all. This is one of the problems that I was asked to do for my General Relativity class. I know this may look a little long, but if anyone can help me out with ANYTHING about this problem, I will greatly appreciate it. Homework Statement Consider the family of hypersurfaces where each...

Hey tiny-tim, thanks! I think you have helped me with several questions in the past, and you're always so kind. You deserve a prize! Oh wait, you do have some awards there I see :p. Anyway, thanks again...

The Kretschmann curvature scalar is defined to be K = RabcdRabcd where Rabcd is the Riemann tensor. I believe I heard in class that this scalar can be used to demonstrate the existence of a curvature singularity. Can somebody tell me why this is so? Also, I heard that it is better (easier I...

Yeah this is a pretty weird problem. One of my classmates is helping me now :) Thanks anyway

Nevermind, I solved the problem.

I think if you click over the red text you see the latex code. Anyway here it is... So it's an integral of: {ab} / {a^2 cos^2 t + b^2 sin^2 t} with respect to t. From t=0 to 2*pi

Homework Statement I have this integral to solve: \int \frac{ab}{a^2 cos^2 t + b^2 sin^2 t} dt The limits are 0 to 2*pi. Homework Equations The Attempt at a Solution I've tried using trigonometric identities, trigonometric substitution... and many kinds of algebraic...

I just don't know where to start. Do you suggest getting the determinant of the matrix and equaling that to 0? That will take so long. Is there some theorem or something? Anybody know? :S

Hi, this is actually for my general relativity class, but I thought I would get more help in the math section of the forums, since it involves very little physics, or even not at all. Homework Statement Take Tab and Sab to be the covariant components of two tensors. Consider the determinant...

Oh, thanks Halls, that was great help. How did you get that parametrization, are they simlpy obtained from the the elliptic coordinate transformations? I found this on wikipedia: "The most common definition of elliptic coordinates (μ,ν) is x = a cosh \mu cos v y = a sinh \mu sin v " Can...