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Single-Particle Electrodynamics - Assassination Science

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in this chapter has been published [65]; this paper is included verbatim in<br />

Appendix F. However, it was found by the author, shortly before the printing<br />

of this thesis, that an extra term needs to be added to the results of the<br />

published paper; this is discussed in detail in Section 4.2.1.<br />

4.2 Newtonian mechanics<br />

In this section, we analyse various classical dipoles from the viewpoint of<br />

Newtonian mechanics.<br />

4.2.1 The electric dipole<br />

The simplest dipole to consider is an electric dipole: a separation of positive<br />

and negative electric charge. Its behaviour is easily derivable, and is not<br />

subject to any controversy whatsoever.<br />

Let us choose to analyse what is arguably the simplest model of a fixed<br />

electric dipole: a positive charge glued to one end of a rigid stick, with a negative<br />

charge of the same magnitude glued to the other end of the stick. (We<br />

only consider fixed moments in this thesis, as are applicable for the intrinsic<br />

moments of spin-half particles; “induced” moments are not, in general,<br />

considered.)<br />

The author shall describe how the following analysis can be made absolutely<br />

rigorous, according to the relativistically rigid body formalism described<br />

in Chapter 3, at the end of this section.<br />

We shall, as with all considerations of this thesis, consider only pointlike<br />

particles in this chapter; but we shall of course start off with an object that<br />

is of finite size, and then take the point limit at the end of the calculations.<br />

Now, an electric dipole moment is fundamentally described by a threevector,<br />

d, in the rest frame of the particle. The direction ˆd of d describes<br />

the direction in which the positive-charge end of our rigid stick is pointing;<br />

117

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