(x-a)^2 + (y-b)^2 = r^2 is the equation of a circle radius r centred at (a,b). So your equation will be a circle radius root x centred at the origin. The inequality indicates that you want the region enclosed by the circle INCLUDING the boundary.
Alternatively you can express x and y as rcos(£)...
To observe a system i.e. gain information about it, you have to interact with it in some way or another. This interaction perturbs the system you have observed.
dem, could you tell me a little more about the 'QCD difference' please? Is it analogous to http://en.wikipedia.org/wiki/Hund%27s_rule" ?
I've just read an older thread which suggests that the difference in up and down quark masses is accounted for be some form of symmetry breaking in QCD...
Aha! Thanks guys I think I've just realized my problem - I forget that the barrier was a potential and not a physical entity such as a wall. I've been studying the 'particle in a box' models - does this then mean that the walls of the box are just potentials and not an actual box?
I believe it is related to the fact that a rotation matrix with a determinant of -1 represents an 'improper' rotation, and a determinant of 1 represents a 'proper' rotation.
http://en.wikipedia.org/wiki/Improper_rotation" .
When a particle tunnels through a finite barrier, does it spontaneously appear on the other side, or does it follow a path through the barrier? If it does the later then does it interact with the barrier?
Thanks
As I said, it was just a random idea - totally baseless in every respect. I'm just curious as to what an electron 'does' when subjected to extremely intense magnetic fields.
I had this really random idea at lunch today - would it be possible to pull an electron apart? I know that it's a fundamental (point) particle and that most likely nothing is going to happen here, but do you think anything exotic could happen, if one were to suspend an electron between three...
Thanks Ben, you seem to be able to describe these things in a way I can understand more easily. The text I reading at the moment is rather formal and I should probably find a better one. Please correct me if I'm wrong here, but would it be right to say that the group of all rotations in three...