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Single-Particle Electrodynamics - Assassination Science

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6.5.7 Computer algebra<br />

All of the quantities listed to this point were originally calculated by hand, by<br />

the author, to the full order of ε indicated. It should be apparent, upon reflection<br />

of the lengthy nature of the explicit expressions listed in Appendix G,<br />

why it was not feasible to continue to compute such expressions by hand.<br />

Thus, the author decided to investigate methods of calculating and verifying<br />

the algebra by computational means. A description of this investigation<br />

is given in Section G.2 of Appendix G.<br />

From this point, the expressions listed in Section G.6 were calculated to<br />

one lower order by hand; the computer algebra programs verified these lowerorder<br />

results, as well as providing the next order of terms. Only one error<br />

was found in the manually-computed expressions, that had not yet been used<br />

for any consequential computations. Once the error in the manual expression<br />

had been located and corrected, the computer algebra program was used to<br />

verify the electric charge field results through to completion (which had also<br />

been completed, manually), and to compute, for the first time, the dipole<br />

field and radiation reaction results.<br />

6.5.8 Gamma factor<br />

Returning, now, to the algebraic derivation, we note that two terms in the<br />

retarded field expressions of Chapter 5 involve the Lorentz gamma factor γ ret ;<br />

however, it will be noted that, in both cases, it appears in the form<br />

γ −2<br />

ret ≡ 1 − v 2 ret.<br />

To compute γ −2<br />

ret , we use (6.56); the result (to the lower order of ε actually<br />

required for this particular quantity) is<br />

γ −2<br />

ret = 1 − r 2 d ˙v2 + r 3 d ( ˙v·¨v) + r 2 d r s ˙v 2 (n s· ˙v) + · · · + O(ε 6 ). (6.62)<br />

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