>In addition to the other fine points: A fundamental job of a life form is to pump entropy out faster than the environment can pump it in. Yes. From a chemistr

>In addition to the other fine points: A fundamental job of a life form is to pump entropy out faster than the environment can pump it in. Yes. From a chemistry perspective, this requires a membrane, or barrier, that separates "life" from "non-life". It also requires mass transport across that barrier in both directions, which would presume liquid inside that barrier. A third variable is the mass of the planet, which dictates which molecules can be present in the atmosphere, and the temperature, which dictates physical states. The requirement for a barrier and mass transport via liquid already imposes restraints on the chemistry that rule out most of the periodic table. Metals lose their electrons too easily. After metals, you're not left with much to work with. Carbon compounds in water is still the best idea we have. Simple long chain carboxylic acids spontaneously make membrane-like micelle structures in water. If anyone has any better ideas, there's a Nobel Prize for the first person to create life from non-life. Go for it.