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Single-Particle Electrodynamics - Assassination Science

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T 0i ≡ T i0 = E×B,<br />

T ij = 1 2 (E2 + B 2 )δ ij − EE − BB. (2.16)<br />

The mechanical stress-energy tensor T µν is always symmetric—not just for<br />

the electromagnetic field, but in complete generality. We shall always use the<br />

symbol T µν for the mechanical stress-energy tensor, and not for any other<br />

quantity; and we shall always use the adjective “mechanical”.<br />

The mechanical angular momentum density (2.15) is likewise contained<br />

in the mechanical angular momentum density rank-3 tensor:<br />

M αβγ ≡ T α[β x γ] .<br />

We shall always use the symbol M αβγ for the mechanical angular momentum<br />

tensor, and not for any other quantity; and shall always use the adjective<br />

“mechanical”.<br />

2.3.6 Electrically charged particles<br />

If a particle possesses an electric charge q, then the corresponding Law of<br />

Nature for its Newtonian force is the Lorentz force law:<br />

F = q(E + v×B), (2.17)<br />

where E and B are the electric and magnetic field at the position of the<br />

particle respectively.<br />

The power into the electric charge,<br />

P ≡ d t W,<br />

is, for an electric charge, simply given by<br />

P = q(v·E), (2.18)<br />

46

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