> isn't gravitomagnetism more of a useful fiction than anything people actually believe models reality? No, it's a real effect and has been measured. > the eq

> isn't gravitomagnetism more of a useful fiction than anything people actually believe models reality? No, it's a real effect and has been measured. > the equations look similar, but there's no physical justification Yes, there is; the justification is classical, not quantum, and does not depend on having any quantum theory of gravity. GR is a classical theory, and gravitomagnetism is present in it, similar to the way ordinary magnetism is present in classical electrodynamics. The difference is that electrodynamics is based on a vector field (the 4-potential) while GR is based on a tensor field (the metric); but that difference just changes some particular numerical coefficients in the equations for gravitomagnetism as compared to ordinary magnetism (for example, the gravity analogue to the Lorentz force has a factor of 4 in front of the v x B term). But these are classical fields, not quantum fields.