Editing Point particle (section)

==Point charge==
[[File:Scalar potential of a point charge.jpg|left|thumb|Scalar potential of a point charge shortly after exiting a dipole magnet, moving left to right.]]
Similar to point masses, in [[electromagnetism]] physicists discuss a '''{{vanchor|point charge|POINT_CHARGE}}''', a point particle with a nonzero [[electric charge]].<ref>{{cite book | first = R. | last = Snieder | year = 2001 | title = A Guided Tour of Mathematical Methods for the Physical Sciences | publisher = [[Cambridge University Press]] | isbn = 0-521-78751-3 | pages = 196–198 }}</ref> The fundamental [[equation]] of [[electrostatics]] is [[Coulomb's law]], which describes the electric force between two point charges. Another result, [[Earnshaw's theorem]], states that a collection of point charges cannot be maintained in a static [[mechanical equilibrium|equilibrium]] configuration solely by the electrostatic interaction of the charges. The [[electric field]] associated with a classical point charge increases to infinity as the distance from the point charge decreases towards zero, which suggests that the model is no longer accurate in this limit.