The polarization itself is determined from the electric force (P,Q,R) by the usual statical formula of linear type which becomes tor an isotropic medium (.f',g',h') = c2(P,Q,R), because any change of the dielectric constant K arising from the convection of the material through the aether must be independent of the sign of v and therefore be of the second order.
Other names for the circular lines are " circulars " or " isotropic lines."
One possibility is to assume isotropic sky conditions at all times and so simplify computation since diffuse radiation is then independent of direction.
A transversely isotropic material is isotropic about one axis.
This is because the glass is optically isotropic, and does not change the polarization state of the light passing tho it.
