I worked with someone like this. He shut down the conversation when I refuted his claim of " no scientific data exists" when I brought up the radar tracking and telemetry from at least two F-16s and multiple NATO ground stations during the mass sightings over Belgium in 1989.

I have come to the conclusion that there are people in this world whom have enough cumulative generational hubris that admitting that there is potentially something out there more powerful than any of us, or acknowledging that current Western preeminence might have a finite shelf life would be so toxic to their self-worth that it represents a clear and present danger to their being.