Back to the Moon with Nuclear Rockets

consumption is the necessary condition for the installation ordisruption of any link, as well as of any metabolic process.From this point of view, the reactivity of a living system is aburst of information-energy exchange within it, in response tostimulation by an external factor, which may in some cases beas small as a single quantum of energy. Reactivity implies theinherent activity of a living system.Bauer's Theory: Structure-EnergySpecificity of Living SystemsIt is possible in many cases to reduce a particular vital manifestationto a physical-chemical process. However, it appearsimpossible to deduce the unity of living processes—their holistic,active, and directed structured process—from the physicsand chemistry of inanimate nature. The most basic difficultiesarise when one attempts to explain those features displayed inthe process of development of living systems. When, on theeve of the 20th century, physicists realized that it was impossibleto deduce the existence of the quantum of action and thefinal divisibility of matter from classical mechanics, Niels Bohrresolved the problem by formulating a set of new postulates.On this foundation, a large edifice of quantum physics is nowconstructed. It turned out also that the principles of classicalmechanics follow from quantum physics and not vice versa.A similar attempt in biology to unite and express in the formof laws the basic features peculiar to all living systems withoutexception, was undertaken by E. Bauer. 14 His first principle("the Principle of Stable Non-equilibrium") is formulated asfollows: "No living system is ever at equilibrium. It continuouslyperforms work against equilibrium, demanded by thephysical and chemical laws appropriate to the actual externalconditions." Thus Bauer asserts that a living system alreadyappears in a non-equilibrium state from its first moment of existence,as a birthright, so to speak, inherited from another living,and hence already non-equilibrium, system.Another feature is equally important: all activity performedby a living system is aimed at avoiding the slide into equilibriumwith its environment. As any living system is out of balancewith its environment, from the first instant of its individualexistence, all its essential structural elements must alsoexist in a state of disequilibrium with the immediate environment.If so, the free energy that a living system uses to performwork against sliding into equilibrium is free energy from itsnon-equilibrium structures, structural energy in Bauer's terminology.Such a form of energy differs fundamentally from theforms of energy encountered in inanimate nature. Non-equilibrium,then, should be displayed at all levels of a living system,beginning at the molecular one. It includes the sustainingof chemical gradients, electrical gradients across membranes,the non-equilibrium state of its macroscopic structures, and soon. Most important, it includes the non-equilibrium of the essentialmolecular components of living cells, a point to be discussedin detail below.As work is performed against equilibrium, free energy isconsumed, and each element of a living system performingthe job, inevitably slides towards equilibrium, finally turninginto ordinary lifeless matter. In order to preserve the non-equilibriumstate, a living system continuously repairs or substitutesits exhausted structural elements. Energy is needed tocarry out this work, and according to the Principle of StableVladimir Vernadsky (1863-1945)Non-equilibr urn, this energy comes from certain inherentnon-equilibrium structures in a living system. Such work,aimed at keep ing an individual living system from sliding towardsequilibi ium, was defined by Bauer as internal work.No matter r ow efficiently internal work is performed, a livingsystem g adually loses its free energy and the matter"charged" witi it, and needs to replace them with matter andenergy (chem cal energy of food, energy of light, and so on)consumed fron its environment. It must seek resources in itsenvironment, separate the useful structure-energy substratesfrom the usek ss ones, and assimilate the former into its ownenergy-chargf d structural elements. All these procedures requirethe perf >rmance of work by a living system. Unlike theinternal work this kind of work is performed on a living system'senvironi nent, and it should be defined as external work.The external work inevitably enters into contradiction withthe internal w )rk. Both share a common source of energy, thestructural ene gy of the elements of the living system. Duringthe performa ice of external work, a living system loses itsstructural ene gy, thus sliding toward equilibrium. Reductionof its non-eqi ilibrium resulting from its own efforts, contradictsthe Princ iple of Stable Non-equilibrium. Insofar as a livingsystem cannot violate the principle of its existence, it mayperform exter lal work only by infringing on the non-equilibriumof its stru :tures, under the influence of external impulses.External influe nces, irritations, infringing to a certain extent onthe non-equili 3rium of a living system, have the effect that theenergy freed i; spent to perform external work rather than internalwork. This provides for the replacement of matter thathas lost its non-equilibrium state by new structures, built bythe living sys'em in an already excited state, and providingtheir ability to perform work.The contra Jiction between the internal and the externalwork follows from the Principle of Stable Non-equilibrium,but it is unresc Ived within the framework of the principle. Theonly reliable ;olution to the problem is the increase of the21st CENTURASummer 1999 23