Classical variables that do not change upon time reversal include:
:, position of a particle in three-space
:, acceleration of the particle
:, force on the particle
:, energy of the particle
:, electric potential (voltage)
:, electric field
:, electric displacement
:, density of electric charge
:, electric polarization
:Energy density of the electromagnetic field
:, Maxwell stress tensor
:All masses, charges, coupling constants, and other physical constants, except those associated with the weak force.