An unidentified flying object is just that: unidentified. Not "identified as alien". The argument is isomorphic to "God in the gaps", for which I think there are few takers here.
I agree. Just observing with your eyes, camera, military ground radar and nose radar a huge yellow-ish glowing object with the diameter of two aircraft carriers, in front of your Boing 747, tracking you as you go, over a long distance, and even following you around in a 360 degree turn is not evidence of little green men. But where do we go from there? There are a limited amount of possible explanations, all which is eliminated as plausible by any one involved (air traffic control personnel, the pilots, military radar stations, meteorologists). It would be...
Recently I've been struck with a belief in Aliens being present on this Earth. It happened after I watched this documenary (and subsequently several others). My feeling of belief is not particular interesting in itself - I could be lunatic or otherwise psychological dysfunctional. What I'm interested in knowing is to what extend other people, who consider themselves rationalists, feel belief in the existence of aliens on this earth, after watching this documentary. Is anyone willing to try and watch it and then report back?
Another question arising in this matter is how to treat evidence of extraordinary things. Should one require 'extraordinary evidence for extraordinary claims'? I somehow feel that this notion is misguided - it discriminates evidence prior to observation. That is not the right time to start discriminating. At most we should ascribe a prior probability of zero and then do some Bayesian updating to get a posterior. Hmm, if no one has seen a black swan and some bayesian thinking person then sees a black swan a) in the distance or b) up front, what will his a posterior probability of the existence of black swans then be?