(Note: I haven’t read Andy Weir’s book yet, so my thoughts here are strictly based on the film.)
The movie was both visually stunning, and entertaining. Gosling carries the entire movie, just interacting with Rocky. I think I could just watch them interacting on planet Erid for 3 hours.
Goldilocks Zone is for Idiots
However, I thought the movie would resolve the points Grace raises in his paper “An analysis of water based assumptions and recallibrations of expectations for Evolutionary Models”, specifically, his claim that “The Goldilocks Zone is for idiots, why everyone is wrong about life”. I thought it will be revealed at the end that Rocky, and planet Erid had a non-carbon based life form. The movie didn’t deliver the twist I was hoping for in the final act. After the movie I did a google search and was dissapointed to find that Rocky is not a non-carbon based life form. So there goes that idea. (I will need to read the book to see if there is anything else).
This got me thinking though. As Grace points out regarding the Goldilocks zone, we are so used to looking for Earth-like conditions that we act like early astronomers who placed Earth at the center of the solar system. It’s the same arrogance just on a different scale.
Does evolution really need water, oxygen or DNA?
The process of Darwinian evolution doesn’t state that life must be encoded using Deoxyribonucleic Acid (DNA) with our specific A-T-C-G four-letter alphabet. Any stable chemical process that an environment can sustain, whether a two-letter binary code or a silicon-based polymer can theoretically serve as genetic material. As long as the replicators are imperfect, natural selection and Darwinian evolution will inevitably take over, driving simple cells toward complex life.
This is how modern astrobiologists actually look for life today, searching for complex, non-random molecular biosignatures that could not naturally occur through non-living chemistry alone, rather than looking for earth-like environments. Even if we did find a planet identical to Earth, with identical DNA, the chance of evolution producing Homo sapiens a second time would be astronomically small. It’ll require the same mutations, same extinction events, same environmental pressures…identical everything. (There can be phenotypical similarity though)
So finally, even though the movie didn’t resolve it, and my idea of Rocky being non-carbon based was wrong, theoretically Grace is correct. Looking explicitly only for the goldilocks zone is indeed for idiots!