Russ, you had a small typo in your Shrödinger quote. Instead of extracting "energy", Schrödinger actually defined living systems as extracting "negative entropy" from the environment: "the only way a living system stays alive, away from maximum entropy or death is to be continually drawing from its environment negative entropy. ..Thus the devise by which an organism maintains itself stationary at a fairly high level of orderliness (= fairly low level of entropy) really consists in continually sucking orderliness from its environment."
You can download the original at http://whatislife.stanford.edu/LoCo_files/What-is-Life.pdf. In the notes area he says negative entropy is equivalent to free energy but didn't want to confuse non physicists. You can see this quote and a nice discussion on by Eric Schneider and James Kay in "What Is Life: The Next 50 Years" http://bit.ly/dO7mCE Feeding on free energy is very similar to Kauffman defining living systems as autonomous agents that extract work from their environment. BTW, Boltzmann also said a related bit: "The general struggle for existence of animate beings is therefore not a struggle for raw materials - these, for organisms, are air, water and soil, all abundantly available - nor for energy which exists in plenty in any body in the form of heat (albeit unfortunately not transformable), but a struggle for entropy, which becomes available through the transition of energy from the hot sun to the cold earth." You can read this chapter at http://bit.ly/hYsuUd On Fri, Dec 3, 2010 at 2:27 PM, Russ Abbott <[email protected]> wrote: > > I his 1944 "What is Life," Schrödinger identifies a fundamental characteristic of living beings as being able to retain a relatively lower level of entropy by extracting energy from the environment. Since As compounds are so much less stable than P compounds the strategy that the As bacterium uses to maintain its low entropy level will probably constitute the most important aspect of this recent discovery. I wonder if these bacteria use relatively more energy to survive than comparable P bacteria or if they discovered a technique to maintain their structure that is not as dependent on stable As/P compounds. > > -- Russ
============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
