Recent content by Cryxic

Perhaps, but it might be easier to find some special superconducting material that has a critical temperature below room temperature and still works at room temperature...let's say because it's super robust against external perturbations. Ultimately it will depend on the mechanism and the...

We don't know the ultimate source of gravitation, and the answers to your questions will have several Nobel Prizes attached to them. Regardless of what gravitation is or what produces it, we know very well by now how it works. As many others have mentioned already, GR is our most advanced and...

You can think of a neighborhood as a collection of open balls, which is equivalent to many other definitions. For example, with regard to the two definitions you gave, a set containing an open set of x can be that open set of x itself. Remember, all sets contain themselves, by definition! In...

To your first question, think about the position vectors that constitute the Bravais lattice. Simply repeating those vectors yields the full lattice structure. Well, the wave vectors k are just another way of reproducing the Bravais lattice, only this time in 'momentum space.' The E versus k...

I might be reading too much into this question, but it seems like the OP was trying to understand the fundamental cause of magnetism. And for the record, to the OP and to everyone else, "that's how nature works" is always a horrible answer because it doesn't tell you anything. You're just...

This is confusing. Are you trying to show that the left-hand side is equal to the right-hand side (which I don't think is true) or are you trying to solve some other problem?

You've got the size of the force down. As for the direction: you have opposite charges, which means they attract one another. So your first answer (the negative one) is the one you should use.

For the first part, you know that the velocity is given by the wavelength multiplied by the frequency. Once you have the velocity, you multiply it with the time interval to get the distance. I'm confused about what the question is referring to in the second part.

Well let's start off simple. We know that 2*pi*r is the circumference of a circle. So the circumference of a circle multiplied by a height h means that we now the have the surface area of a cylinder (excluding tops). Do you see that at least? Once we have the surface area, it's just one more...

It's the energy associated with motion, as opposed to potential energy, which is associated with position. For example, if you're standing still holding a soccer ball in your hands, the ball has potential energy. In other words, it's got the "potential" to do something (to fall to the ground)...

I am a radical, social liberal. I support a strong welfare state that helps people assert their identities along with growing global cooperation and interdependence.

You're partly right. The number of microstates available to the human body far exceeds those available to a simple piece of rock, hence the human body has greater entropy. For that same reason, liquids have greater entropy than solids, which is what you concluded for different reasons.

Your result is close but awkward on the first part. Go back and redo the integral. You should get the square root of 2 divided by a, not 1 divided by a. The bounds of integration are 0 to a. Given what you've presented here, the width of the well is a. You have the right idea for the second...

You would need to use the centripetal force equation. If the radius was four times smaller, the force needed to keep the bull in orbit would be << answer deleted by berkeman >> times bigger.

Shankar's Principle of Quantum Mechanics has a similar question, and that question asks for the possible L(z) angular momenta and their probabilities. That's what I assumed this person was trying to find, although that's not stated anywhere. Either way, it's all simple. The r^2 part will just...