Re: How Alien is Alien?
@itzman
"WE are looking for aliens who are in fact not alien, but are just like us."
Well, yes, that's true and it is of course possible that there is intelligent life somewhere out there that is of a form beyond our current understanding.
It is a conceit to believe that we fully understand all the laws and processes of the universe but we have a good enough grasp to make some decently informed inferences and there is no particularly good reason to believe that life elsewhere operates under physics that are substantially different from that which we understand here and now, which is not to say that their grasp might not be substantially better.
But that's almost beside the point as we are limited by our technology and grasp of physics so we can only 'look' for signals that we are able to receive and identify.
It certainly might be possible that some advanced civilization is capable of generating sufficiently strong gravity waves to be used as a form of long-distance communication but, LIGO not withstanding, we lack the means to detect and interpret such hypothetical signals and certainly to respond in kind.
Thus, as our both our methods of detection and the scale of the exercise itself are limited, we must restrict ourselves to the search for intelligent life using similar methods that we do and could use and thus, presumably, similarly limited in their signal detection and planet identification abilities.
So the search for a particular subset of life that is basically similar in the physical barriers it faces (even if more advanced) is not so much a presumption that life all life must be similar to us but an acceptance of our own limitations.