Here’s an interesting spin on the idea of extraterrestrials…one scientist believes that “aliens” are most likely to be robots/artificial intelligence who are nearly immortal.
Per Susan Schneider of the University of Connecticut and the Institute for Advanced Studies at Princeton:
I do not believe that most advanced alien civilizations will be biological. The most sophisticated civilizations will be postbiological, forms of artificial intelligence or alien superintelligence.
The reasoning behind this is that any sufficiently advanced race—advanced enough to travel through the vastness of space and find our charming selves—would have “surpassed” their mere mortal shells aeons ago.
And not only would they be likely to be made of non-organic material…but they’d also be extremely ancient (because they would be technically immortal):
…all lines of evidence converge on the conclusion that the maximum age of extraterrestrial intelligence would be billions of years, specifically ranges from 1.7 billion to 8 billion years.
As with some of the more “respectable science” stories (such as the idea that DNA can be used as “hard drives” for information), we have here a case where the “kooks” have been saying stuff like this for years.
Philip K. Dick had hypothesized in his Exegesis that the “alien”-type entity that had been contacting him, VALIS, might have really been a highly-advanced AI. And some people who have claimed to have been abducted by aliens—particularly the classic “grey” variety—have said that they are actually some sort of non-organic “robotic” creatures.
Of course…if these aliens are immortal robots with one would assume extreme intelligence…then perhaps Stephen Hawking’s opinion that they will also basically see us all as cockroaches might be true as well. Which would, you know, suck.