Paolo, simple because something is "unprovable" does not mean that it does not exist.
absolutely. we agree that even with the odds of 9999999999999999 - 1 of something not existing... there is still a slim chance that it does. but....
how many people in the world when asked would state without doubt that there is a god / alien / pixie / tooth fairy / santa claus / UFO etc.....?
Are these things "wishful thinking" because science can't "prove" what is happening, at this point in time? Were bacteria, virus, and plague "wishful thinking" before a cause could be proved by science?
i completely agree with you. i think it is healthy to retain an element of agnosticism in even the most confident conclusion, if for no other reason than to acknowledge the limitations of our comprehension.
a good example from my own melon, is that there is no such thing as infinity. ironically, the concept of something without end only exists, because our intellectual capacity is too FINITE to perceive it!
but we can only go on what we know. i might claim definitively that there is no such thing as 'x', on the basis of what we think we know right now..... but we are not incapable of considering PROBABILITY.
otherwise, why stop at aliens in space or god on earth of fairies at the end of your garden? why not imagine a tea pot orbiting the sun? just coz you cannot prove it is there, should we suspend conclusions that it is insanity to presume that it is?