  The observation of gravitational waves by the three LIGO-Virgo
interferometers allows the examination of the polarization of gravitational
waves. Here we analyze the binary neutron star event GW170817, whose source
location and distance are determined precisely by concurrent electromagnetic
observations. Applying a signal accumulation procedure to the LIGO-Virgo strain
data, we find ratios of the signals detected by the three interferometers. We
conclude that the signal ratios are inconsistent with the predictions of
general relativity, but consistent with the recently proposed vector theory of
gravity [Phys. Scr. 92, 125001 (2017)]. Moreover, we find that vector gravity
yields a distance to the source in agreement with the astronomical
observations. If our analysis is correct, Einstein's general theory of
relativity is ruled out in favor of vector gravity at 99% confidence level and
future gravitational wave detections by three or more observatories should
confirm this conclusion with higher precision.
