Carbon and water are very good at producing life, hence earth, but that doesn't preclude other chemical systems supporting something life like, and even one example of such would change the way we look at the emergence of life. I think that makes the question of non carbon abd water life worth considering, even if it turns out to be incredibaly rare, or inherently limited to very simple forms.

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For me it's enough for the garden to be beautifull; why do so many want to see fairies at the bottom?

"Many of those people are not getting four when adding two and two; many of them aren't even getting five or twenty-two. They're getting potato."
Gillianren