first to rndbush - That is a ridiculous thing to say, there is no one that can keep a secret of such high technology from so many people.
I totally agree that aliens are not here. They exist outside our solar system but the chances that they have come to our planet is VERY small, considering the huge, almost insurmountable obstacles. The lights was a good point. Many things about this psudoscience don’t add up. The shape of the crafts is unreasonable as well as inefficient. Absolutely NO hard evidence is ever found. The government is bad at keeping secrets, almost anything they do ends up in the open. Maybe a few years after the fact but inevitably out in the open. No quantum leaps have been made in technology (a previously made point). However, the biggest reason hasn’t been address yet. WHY???? Why would an alien race travel millions of light years and abduct people just to have sex, perform sexual operations, or warn about impending doom of the earth to a very select few and leave no evidence? There is no reason to visit us and hide. Motive is an important missing piece.
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If the theory does not fit reality then reality MUST be changed.