Editorial note to : Hans Thirring , On the formal analogy between the basic electromagnetic equations and Einstein ’ s gravity equations in first approximation

The paper contains some inconsistencies and errors, and an undefined quantity, which, however, does not invalidate the final equations for gravitomagnetism. Since in a realistic rotating body (angular velocityω) there arise centrifugal stresses of orderω2, it is inconsistent to incorporate the velocitiesv′ of thefield-generating body up to second order but to treat this body as incoherent matter (dust). The same inconsistency appeared in Thirring’s model of a rotating mass shell [1], which therefore did not correctly solve the Einstein equations (in the shell). For this case the inconsistency was observed and corrected by Lanczos [2]. In the present paper the inconsistency has no severe consequences because the second order terms in v′ anyhow are quite unimportant. An error in Thirring’s paper appears in the integration volume dV0 which has to be substituted by dV = dV0/(dx4/ds). The same error appeared in Thirring’s paper [1] on the rotating mass shell, was there observed by M. Laue and W. Pauli, and corrected by Thirring in [3]. But, as with the inconsistency with the incoherent