Recent content by Dburghoff

You misread the topic creator. By "U!=0", he actually meant U \neq 0. In computer programming languages, "!=" is often used to denote "not equal to."

Now, I'm not a physicist (just a first-year engineering student), but I'd like to venture a guess why. I've actually thought of something like this, Gonzolo, but I came up with an explanation which satisfies me, and I think will satisfy you as well. The whole premise behind GR is that it is...

No, it's not possible. For example, suppose that all of the angles were right angles. You have one side's length, but how would you know whether the figure is a square or a rectangle? You can't. Suppose the side you are given has length 1, and all the angles are right. The side across from the...

As a freshman college student (in Calculus III), I'm kind of offended by the blanket statements flying around here. I spend at least a half hour every day studying from my notes and reading the next section (so that I may be able to participate intelligently in the next lecture), and that's in...

Put another way, there are two kinds of matter: "regular" matter, which is composed of the familiar protons, electrons, and neutrons (along with other quark combos and leptons and whatnot), and antimatter. Every "regular" particle has an associated antiparticle, which has the same mass but the...

That only proves De Moivre's for natural numbers, though. I believe (and correct me if I'm wrong) that you must use Taylor series / Euler's formula to prove it for all reals.

Which is most easily proven with Taylor series. :wink:

I must say that I'm impressed with your doing that without knowing about Taylor series. Basically, a Taylor series is an approximation of a function using infinite polynomials. They can be centered around various numbers, and are of the following form, where a is the center of the number...

Furthermore, you don't have to test every number up to the sqrt(n), just 2 and all of the odd ones.

Count up the negative signs: one from subtracting the result of the integration by parts, and one for using the derivative of \cosh x, which is -\sinh x. You should be adding the the antiderivative, not subtracting it.

Well, pi can be expressed in terms of the sum of the arctangents of a bunch of Fibonacci numbers. Does that count?

My guess is that he'd float. He'd be on the inside of a Faraday pail. Just as there's no electric field on the inside of a hollow sphere, there would be no gravitational field (at least due to Earth) on the inside of the gigantic massive sphere.

You know, I'm not a thermodynamics expert or anything, but I've got an idea. What if we're looking at this in the wrong way? Suppose that these people have created a "Maxwell demon" which creates electrical energy from heat energy. When they measured the current, that energy was most likely...

Hello, everyone! I'm working on a simulation of charged particles, and I'm trying to figure out a way to get exact equations which fit the particles' motions. However, I've arrived at math which is very difficult, so I thought that I'd ask for help. Basically, I want to know how to find the...

Right, but I'm trying to consider how the gas as a whole behaves. The movement of individual air molecules will most likely be slowed by the neutral molecules that it slams into along the way. So, will the rms speed of all of the charged molecules remain about the same as the uncharged ones?