In a new TEDx talk, Alex calls for a science of UFOs ... Why Bob finds two naval sightings credible ... Alex: "There's some decent chance that these things are alien" ... Alex's proposal for a UFO monitoring system ... Might it be suicidal to let ETs know that we know about them? ... Alex: Maybe the aliens are waiting for us to figure it out ... What explains the taboo against academic study of UFOs? ... Alex's willingness to be misperceived as a crank ...