I don't agree that human thought patterns have to be rare, or your other assumptions. The only safe bet in this discussion I think, is, we don't know anything f

I don't agree that human thought patterns have to be rare, or your other assumptions. The only safe bet in this discussion I think, is, we don't know anything for sure. > At some point we're either going to murder ourselves or create a Von Neumann machine capable of interstellar flight. There are many, many possibilities for human futures that are between those two and not do extreme. It is absolutely possible we survive millions of years without interstellar travel or self destruction. > Since that obviously hasn't happened with alien machines I also think it is not so obvious that this hasn't happened or isn't happening with alien machines. It certainly could be and we would not know either way. A la 2001: A Space Odyssey, perhaps in fact we are a product of alien machines themselves.