A Search for Alien Life Begins in Earth’s Oldest Desert
theatlantic.com
theatlantic.com
For example - Think of yourself an ant living next to a river. The ant would have no prospective or understand of what is going on in the river and all the fish inside it.
Unlike ants, we can use our rationality to go beyond our senses. Instead of looking at rivers we look at space, planets around stars light years away.
If you're looking for X and have no idea what this X is, then you won't be able to find. Thus, they probably only look for what's familiar or defined as "life form".
I know I have an unpopular opinion here, but I just don't see it happening. It seems like wishful thinking to expect to find life extraterrestrial life. Of course, I'd love to find out I'm wrong. But what is the observable data to suggest otherwise?
I think of the early history of our own planet. Sun and shade, heat and cold, tides causing wet and dry in phases unsynchronized with the other effect. A tiny random chemistry lab on every grain of sand on every beach for a billion years. What are the odds that life wouldn't happen? A more interesting statistic in my view.
* humanity doesn't extinguish it's own flame
* there isn't some freak, inescapable, immitigable cosmic occurrence before we've gotten out of our own solar system
* we develop technology for near-lightspeed or FTL travel
If the above were true, I think the only thing that would stop us from finding non-Earth-origin life some time before the heat death of the universe would be if there is actually no other life out there, which I think is unlikely.
However... I do think that there's basically 0.0% chance of finding extraterrestrial life in the deserts of Earth, excepting in the case that the spontaneous generation of simple life is exceedingly common. But, I guess determining how common that might be is one of the goals of the search.
Technically the term encompasses the former too, but all too often people seem to equate it with the latter.
Personally I am more convinced by the "rare Earth" hypothesis too, and I don't believe humanity will discover complex alien life ever thorough its existence. Obviously I understand why this point of view gets the boos.