Hello all,
I have a question concerning the best way to access random elements in a large file. I have a single data file of numbers, 12G in size with dimensions 1024x768x16384. My goal is to, as quickly as possible, load, say 16384 of those numbers into memory. Assume these numbers are not...
So this is getting trickier. I have attached two files: One is the Fourier transform of just a "square", and the other a "square annulus". I did these two numerically.
If you make something like
\frac{4 \sin\left(\frac{k_x}{2}\right) \sin\left(\frac{k_y}{2}\right)}{k_x k_y}-\frac{4...
I don't know if that quite does it. In that case, the annulus still has some thickness... I want it to be a true delta function.
I think that if one could take the derivative of the two dimensional box function and use that, then maybe something tractable might pop out...
Hello all. I'm trying to compute the Fourier transform of a square annulus analytically. A "square annulus" would be the square analog of an infinitely thing ring (circular annulus). Here's what I know:
The Fourier transform of a circular annulus is a Bessel function. In polar coordinates...
Your reference is spot on. And the fields do get pretty complicated :)
Word to the wise though: if you have to do an experiment, don't rely on the magnetic result from (e.g. Jackson). Cause you will go crazy. Other non-dipole forces behave a lot easier.
I think the main problem with your argument is you are trying to understand the implications of physics through logical reasoning. You do not want to go down this path. I urge you to learn the math first, and then try and make deductions based on what you think the math is telling you...
I'm not 100% sure what you're asking, but solutions to differential equations (like the damped harmonic oscillator) are best solved by use of complex variables.. the complex exponential in this case. Read the Wikipedia page on "Harmonic oscillator" and it explains it. A sin or a cos is only...
I disagree with chrisbaird. Not all central force orbits are stable. In fact, (Bertrand's theorem) only TWO types of orbits are stable: inverse-square law (gravity, electrostatics) and a radial harmonic oscillator type.
The attraction between two magnets is certainly NOT 1/r^2. I can't...
sophiecentaur's right. If you have a potter's supply in town, just go down and see what motor they have in the units they're selling. The manufacturer has done the research for you!
Actually, and I didn't know this until a couple of weeks ago, but the first detection of relativistic effects were done HERE on Earth using two clocks in a tower. One clock on the top of the tower and one clock at the bottom. The difference in the curvature of spacetime caused by the Earth at...
Those glass plates are what I used as an undergraduate. You do need a fairly stable table though. But any laser powerful enough to expose the film will work. The chemistry is as easy as developing photographs in high school.
I did some tests with regular film and it will NOT work. The...
You've hit on one of the great unsolved problems in QM. Wiki "quantum chaos" or the "correspondence principle" for more. The answer isn't so clear cut.
I didn't say Einstein. Matter warps spacetime... and the gravitational potential energy well is just a good example of that.
Why do you say that it only has the "appearance" of orbiting the point? 4 and L5 are potential energy wells... can't think of a reason why they wouldn't be orbiting...