This was the title of Stephen Hawking’s latest Genius episode I watched on Wednesday evening. Very entertaining, and his imagination and humor comes through as he leads three volunteers through a journey of discovery using quite elaborate “visual aids.”
In the hour-long show he leads his subjects to understand that there are hundreds of billions of stars in just our galaxy and that many of these have planets and some of those would contain water and would be the right distance from their start to allow life to evolve.
Then, in his speculations near the end, he makes fundamental error of thought – one shared by many others including Carl Sagan. That error is that our experience can be generalized to all experience. In this case he assumes that “intelligent” life would evolve on these planets in the same way it has here.
Actually there are several errors of thought here. The first is a common example of human egocentricity: intelligent life means us and equates with language and technology. In this way he discounts the other animals here as not qualifying as intelligent life, a most questionable assumption.
The second is that life evolving on other planets would evolve as it has here into technologically advanced “civilizations.” This is the crucial error; there is absolutely no reason to assume life on any planet would evolve the same way it evolved on any other planet. Even on Earth where all life that we have discovered is genetically closely related, life is amazingly persistent and adaptive, growing under conditions we could not survive. There is no reason to assume that life elsewhere would be restricted to the same genetic structure that we see here. We really have no idea what the possibilities are. Life elsewhere might be nothing remotely similar to what it is here.
The nail in the coffin assumption he makes, though, is that we would be able to communicate with these alleged civilizations elsewhere if we could overcome the speed limit of light. So hundreds of years after Galileo proclaimed we are not the center of the cosmos, even brilliant people like Hawking still unconsciously cling to the “humans are the crown of creation” myth. This myth leads to assuming other civilizations, while possibly more technologically advanced than we are, could or would even bother to communicate with us. I think rather that they would be so different from us that they might think of us as interesting specimens to study and run experiments on. If we were really unlucky, they might be like us, in which case if they could come here they would collect us as specimens for experimentation, hunt us for sport or just wipe us out and colonize Earth. I doubt we would sit down to tea and have a pleasant conversation about our respective planets.
In short, it seems all of us, including bright scientists, can fall into the trap of thinking of ourselves as basically the best nature can come up with and that our experince can be extrapolated to other worlds.