What does it mean to be alive? Science, shockingly, still doesn’t have a consensus. For example, is it fair to say that the novel coronavirus now sweeping the world is alive? The short answer is there isn’t one agreed-upon answer — for something so basic, you’d think life would be easier to define.
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A lot of the debate comes down to the fact that the various fields of science approach the topic quite differently. …
But beyond that, most of these definitions of life fall short in another, very subtle way: They are based on the origins of life on our planet. This means our hypotheses for what sentient and conscious aliens look like almost always reflect humankind. You only have to look at a Star Trek episode to see it — humanity likes to make the world in our image, which is partially why in sci-fi and fantasy a lot of the “aliens” look a lot like ourselves. (Okay, and because it’s easier to dress a human up as a humanoid alien).
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If our definition doesn’t even work correctly with the systems we observe on our planet, it’s incredibly likely that in the larger universe there will be systems that break this definition as well.
