Monday, November 10, 2014
wikipedia talk page on entropy and life article
Is there any reason the internal energy of G = U+pdV-TS can't be used to directly decrease entropy S without using up too much G? When life makes copies of itself it is by definition decreasing entropy S at least for an isolated portion of the system. Why can't the entire system decrease total U to decrease total S at only small sacrifice in G? I do not doubt that life is so inefficient that total S is being increased, but if life were much more inefficient, why can't S be decreased as photons are captured and utilized? This would be like a carnot cycle that never return back down the other half, and is always converting energy from the photons into moving matter to make copies of itself, not substantially reducing the G the photons original obtained (which I see derivation for from photon momentum). So perfect efficiency to use internal energy to make copies would be the ideal life. So solar cells powering electrical motors being 1000 times more efficient than photosynthesis driving muscle may have some higher moral claim, assuming you think evolution is a good thing, to occupying the Earth. Using the more general form of free energy instead of Gibbs, the goal of life is then U1-U2 = T1*S1-T2*S2.