@HiroProtagonist When I was younger, and I've always been a Star Trek fan, I thought the episode with the Horta was fun. Silicon being in the same period table row as carbon seems like a natural alternative for life. There are issues though, the bond angles are different which makes long chain molecules more difficult, you can create them but it's like /-\-/-\ chains instead of +++++ chains, so long chain molecules like DNA and RNA don't work. Also, carbon can be oxidized into a gas and easily inhaled, but silicon is oxidized into a solid (quarts in crystal form) so not really good for a biology that depends upon oxidation for energy. But perhaps robotics powered by silicon AI will become a form of life, who knows.