D O C U M E N T 4 2 2 J A N U A R Y 1 9 2 3 3 6 1 . Then the Maxwell- Lorentz equations can be written thus: , . For the energy-momentum tensor one could might try setting up the symmetric expression: For, at rest one obtains 1) = , 2) Tμ:------------------, σe ρv + 1 v2 – i---------------------- σ(ev) ρ + 1 v2 – - ∂ ∂xν ------- - εϕμν 1 μ -- - ψμν + Iμ = ∂ ∂xσ --------( ϕμν ψμν) + ∂ ∂xμ --------( ϕνσ ψνσ) + ∂ ∂xν ------- -( ϕσμ ψσμ) + + + 0 = Tμν εϕμαϕνα 3 4 --δμνϕαβ2 - + = 1 μ -- - ψμαψνα – 1 4μ ------δμνϕαβ 2 + δμν 1 0 = 1 μ - ϕμαψνα ϕναψμα). + ( –-- εϕμαϕνα 3 4 --δμνϕαβ2 - + εex 2–--εe2 1 2 - εexey εexez 0 εexey εey–2εe2 1 -- - εeyez 0 εexez εeyez εez– 1 2 --εe2 - 0 0 0 0 1 2 --εe2 - 1 μ - ψμαψνα –-- 1 4μ ------δμνψαβ2 +