  A critical look at the Landau-Lifshitz equation, which has been recently
advocated as an "exact" relativistic classical equation for the motion of a
point charge with radiation reaction, demonstrates that it generally does not
conserve energy-momentum. Its failure is dramatic in the one-dimensional case
of a stepped electric field, where it predicts discontinuous velocity and thus
infinite radiation. The Lorentz-Dirac equation, on the other hand, in spite of
its preacceleration over distances comparable to the classical electron radius,
does not display such problems.
