For several years now LIGO laser gravitational wave detectors have been in operation around the world. More sensitive than originally planned, according to the Standard Model of physics predicted by fundamental Einstein general relativity theories, LIGO should detect several gravitational wave "incidents" per month. But the pesky real universe has its own perverse way with authoritative human theoretical model hubris as yet again the news is 'none detected'. So, how long does the null result (not limited to one detector) have to continue before the standard model of physics and its grav wave predictive model is considered falsifyed?