I didn't suggest humanity had no imagination just that it is limited in what it can conceive.....just as we created gods in our own image we also create aliens too that resemble us & travel in space ships that we can recognize as such because we can't imagine extraterrestrials acting any differently from what we would do. I don't deny that there are probably other forms of life in the universe either, given the quantity of planets & suns out there, statistically there must be other planets that are propitious to creating & supporting biological life & no doubt other life or energy forms exist that we just can't begin to imagine. What I am sceptical about though, is alien visitation on earth. Our conceit drives us to believe that any intelligent alien life would try to contact us because we too are intelligent & interesting enough to warrent such a visit. Any aliens capable of long distance space travel wouldn't be a "couple of thousand years more advanced than us".....they would be more advanced than us ( & completely different from us) as a species, period. We also too readily presume that any 'intelligent' or advanced alien life forms would naturally be space explorers......yet another anthropomorphism.