Only the lowest non-zero multi-pole moment is coordinate independent.
| -----Original Message-----
| From: Ludwik Kowalski [mailto:kowalskil@MAIL.MONTCLAIR.EDU]
| Sent: Wednesday, January 21, 2004 4:37 PM
| To: PHYS-L@lists.nau.edu
| Subject: Re: point particles
|
|
| On Wednesday, Jan 21, 2004, at 17:00 America/New_York, Dan
| Crowe wrote:
|
| > A multipole expansion can be calculated for any charge
| distribution,
| > including a single point charge. The multipole expansion is
| > calculated relative to a particular coordinate system. If a point
| > charge is not at the origin, the dipole moment, relative to the
| > coordinate system, is nonzero. See, for example, Eyges or Jackson.
|
| Are you saying that the magnitude of the dipole
| moment of a "system" can have any value,
| depending on where the origin of our coordinate
| system is? I was under the impression that the
| dipole moment is a system property, like its total
| mass or charge. Is this wrong?
| Ludwik Kowalski
|