speaking of solid, liquid, gas, and plasma, where in nature do these four states of matter interact to form a discrete system? the only example i know of, with my limited knowledge, is sun (plasma), earth (solid), sea (liquid), and sky (gas) ... all work together to form something like a "gaia" system which sustains biomass. this may be a bit too novel, i'm just wondering if there are places in nature where these four principal states of matter work together, perhaps in a type of cell, engine, or some astrophysical phenomena. strange question. I know this.