Godfrey-Smith argues that for a mapping to constitute a genuine implementation, the microscopic physical states that are clustered together (to correspond to a given computational state) must be physically similar to one another — there cannot be arbitrary groupings of arbitrarily different physical states, as in the arguments for unlimited pancomputationalism.
However, it is unknown whether these macroscopically observed structures correspond to the conformations of individual residues, or to an average of microscopic configurational states that are composed of groups of residues.
Protein surroundings near haem III control its reduction potential relative to the other two haems, which in turn controls the microscopic redox states that can be accessed during the redox cycle, establishing preferential pathways for electron transfer.
Both realized that equilibrium values for quantities could be calculated by imposing a probability distribution over the microscopic dynamical states compatible with the constraints placed on the system, and identifying the observed macroscopic values with averages over quantities definable from the microscopic states using that probability distribution.
In that work, it was proposed that the relative high reduction potential value of haem III was crucial in selecting the microscopic redox states that the protein can access during its redox cycle and, thus, in establishing the preferential pathways for electron transfer.
If the diagram represents the only reaction of the system, then it is possible to apply the principle of microscopic reversibility, which states that the course taken by reverse action will be statistically identical with that taken by the forward reaction.
Study of this question has been made difficult by the spectroscopic limits of resolving microscopic ensemble sub-states that exist under the conditions of physiologic temperature, pressure, and hydration [12].
Maxwell, introducing the notion of a "demon" who could manipulate the microscopic states of a system, argued that the law of entropic increase was only probabilistically valid.
For instance, assuming a uniform distribution of microscopic states in macroscopic cells, it follows that the microscopic states of two spatially separated regions will be independently distributed, given any macroscopic states in the two regions.
This view holds that uncertainty may be quantitatively expressed as H in terms of a probability distribution for the occupancy of microscopic states available to a thermodynamic system, following the form of (8) for a two-state system.
