Have they made physical contact with us? I mean, beyond the psychosexual tales of anal probing. Are there any improvements in science and technology that have been given to us by the inhabitants of those UFOs? I think the answer to both questions is no.If such craft exist, and their points of origin are extraterrestrial, I believe they consider this planet to be the backwater of the galaxy. Any entry they make into our atmosphere is quite by accident, like taking the wrong turn on a dark road at night.But, my personal belief is that we are quite alone in our galaxy and those nearby. It takes a certain combination to have a planet orbitting a sun at just the right distance, of just the right size to seize and hold an oxygen-nitrogen atmosphere in order to foster the development of carbon-based sentient beings. Earth happens to be that lucky little orb.