Of the millions upon millions of species that have existed on this world, humans are the only ones that have developed technologies capable of space travel (although dolphins and the like might have if they weren't water bound) I find it very unlikely that there are not millions of other worlds teeming with life. I also find it unlikely that big brains, while rare, are not also common given the vast numbers of species' that take hold when multicellular life dominates.

So what stands in the way of finding other space faring civilizations? Well, first of all most big brained creatures are more like dolphins, elephants, monkey's, whales, hippos and the like.. So genetics is a big part of ...

Of the millions upon millions of species that have existed on this world, humans are the only ones that have developed technologies capable of space travel (although dolphins and the like might have if they weren't water bound) I find it very unlikely that there are not millions of other worlds teeming with life. I also find it unlikely that big brains, while rare, are not also common given the vast numbers of species' that take hold when multicellular life dominates.

So what stands in the way of finding other space faring civilizations? Well, first of all most big brained creatures are more like dolphins, elephants, monkey's, whales, hippos and the like.. So genetics is a big part of it. Then there's culture. Even big brained creatures with the potential for space flight spend a lot of time spinning their wheels. Then there's the dangers of technology's double edged sword described in the article. My theory is that there are far more advanced space faring beings out there but not only are they quite different from us so are their technologies. The latter would consist of nanotechnologies that would allow them to continue on their explorations imperceptibly. It is also quite possible that there is not too much difference between them and their machines.