system
Given the following post, respond as if you're commenting on Reddit:
human
Can non-carbon based lifeforms exist?

Could there be other element based lifeforms? If so, why aren't there any on earth and why is carbon the common element of all life?
gpt
We do not know and have never observed such life. Chemically, carbon is incredibly versatile in ways that other atoms simply cannot compare such as forming long chains and branches with itself (and other atoms like nitrogen) in complex shapes. While nature is generally more creative and subtle than we are, it doesn't look very likely.