Dear Brig

At the beginning of the new year I wish to recall the following flash of reality; I think one could well dedicate this quote to the memory of those who have passed, for the relief of those who are still passing, to the hope of those who will pass.

"Mankind has not changed much since the days of Cro-Magnon man, days separated from our own times by a thousand generations. Every one of us has an immense line filled with stories of struggle, heroism, self sacrifice, that if we did but know it would put the parochial affairs of the past few generations to shame. Every one of us has an immense line that would sweep even the greatest dynasties of recorded history into affairs of minor consequences. And before Cro-Magnon there were upwards of ten thousand generations, so many that the imagination is too staggered to conceive of what happened to them all on a generation-to generation basis. What we actually see are nothing but bits of foam at the surface of the vast ocean of prehistory." Fred Hoyle - Home is where the wind blows - end of chp 3.

Have an happy new year... Gabriel Manzotti / Monza / Italy

S = Entropy,
k = Boltzman's Constant,
log = Natural log,
X = Number of States in a system.

Entropy is simply a measure of the number of states in a system. Physicists have long used logarithms to handle large quantities. Every state is associated with an energy, and processes generally dissipate into states which have lower energies. In otherwords, single high energy states dissipate into many low energy states.

Take an example from Shu's "The Physical Universe". (CH3 or CH4)

Consider a simple system, such as a photon. It could start as a gamma ray generated in a fusion reaction between two hydrogen atoms in the Sun. Over a 100,000 years it bounces around inside the Sun interacting with plasma slowly degenerating into many other photons all of the wave-length of visible light.

Having left the atmosphere of the Sun a fraction of these photons have a chance of interacting with the Earth. Some are reflected back into space, others are absorbed by ground either to re-radiated as infra-red radition or turned into convective motion for the atmosphere or ocean currents. Some even reaches life to sustain the processes which keep it alive.

But the key thing to remember, whether it be living systems, or an interaction with inanimate matter, the net effect of visible photons of light interacting with the Earth, is the expulsion of a larger number of photons leaving in the infra-red. Conservation of energy is preserved with only an increase in entropy.

It is far easier to discuss entropy from a micro-scopic, quantum, perspective that a macro-scopic, phase changing, high level one. The sense of the fragmentation of system is lost on the ordinary reader. Keep it simple.

(Aside) Contrasting the difference between "Open system" dynamics, such as above, and Thermodynamics, "Quasi-closed" systems dynamics, is the right way to go. Ilya Prigogine work in chemistry in analysing far from Equilibrium states in open systems is valid, as even he claims there is where life can be analysed. Traditional thermo-dynamics only analyses interactions between systems in near equilibrium, largely because they are simpler. Chaos is just far to complex to breakdown in any exact linear fashion.

Logical entropy appears to me a misnomer. Your just really talking about plain entropy from an information theory perspective. There is an interpretation that

" Entropy is a measure of the amount of information we have discarded when we view a system from the outside: the movements of a gas as a temperature, a series of letters as a number of symbols. If we are inside the system, we can obtain this information if we can be bothered. If we are outside the system, we have 'thrown it away' - or have never possessed it."

The User Illusion...Tor Norretranders

(Aside) Norretranders discusses a concept of exformation and logical depth in the context of computation and algorithmic complexity theory. This is an interesting advance on discussions on just the second law of thermodynamics. His ideas are applied to consciousness. Could not the same analysis be applied to living systems?

Living systems have a phenotype and genotype. The first is the physical manifestation of the system. The genotype could be considered to be the exformation by which the physical manifestion operates and is built. The genotype itself is as open to change as the phenotype that it directs and assembles. The question as to the origin of life has always been the 'chicken and egg' problem. Which came first? Is it possible for a genotype to exist without a phenotype? And if the phenotype is more important, what are the necessary and sufficient conditions for the initial phenotype to form and hence have a structure to support the genotype? What is the initial exforming process, that is required to produce a self replicator from basic chemical compounds? And how much entropy, or energy fragmentation, is discarded in the process of producing this resultant residue?

And thinking around this subject, particularly with respect to Godel-Chaitin Complexity, would it not be reasonable to investigate whether life is a necessity for production of more life....

[Klyce, 27 July] I have one primary disagreement with you. You say, "Every state is associated with an energy...." Every physical state may be associated with an energy, but information is theoretically independent of energy. Practically, encoded information has a physical carrier, but the content is the same, whether the carrier is newsprint, radio waves, magnetic tape, skywriting, DNA, whatever.

[Doug, 30 July] The rendering of any physical state, or ensemble of states, has an energy, or array of energies, associated with it. We agree....

The fundamental currency of any physical interaction involves energy interchange. How can you have information without energy? Information interchange involves energy interchange or transferal.

If you've dealt with quantum mechanics you'd have discovered that each state, has an energy associated with it. As you build up to a macrostate you have countless numbers of substates making up the system your investigating.

The split in ideas between Thermodynamic and 'Logical' entropy occured to me in my undergraduate years. It was this study of the quantum nature of matter which allowed me to see how the small makes up the large....

The physical medium upon which the message is carried or stored has states, and energy which is dissipated. A certain type of frog can register the reception of light when receiving 5 photons of light. There gives the lower bound in energy usage and bandwidth for the communication of a simple message.

If your talking about the representation of information, quantising information, 1's and 0's, yes this representation can be in held in different forms. There is a practical energy cost in en-scribing the medium upon which it is stored, and even and energy cost in accessing that medium to return the information that it contains. Shannon's information theory goes into great detail about information transferal and maximum bandwidths, but he doesn't discuss meaningful content. You may have information, but do you apprehend what it means. You may have a CDROM of an encyclopaedia, with a lot of information, but unless its in a language you understand its just noise. But the measure of Shannon's information for two equivalent CDROMs, one with noise, one with meaningful content, is the same.

This information is still render and transmittied as physical states. What you are suggesting is the information is metaphysical. I think that it is physical and that it can be be measured.

The interpretation that is tendered in my last email is that entropy is the information discarded when viewing a system from the outside....

I thought that another line of thought on the nature of entropy would be valid to bring into this forum. My summary of physics boils down to a quip derived from two Irish geniuses; William Caley Hamilton derived the 'least action principle' which applies from General Relativity to Quantum Mechanics; Lord Kelvin formulated the Second Law of thermodynamics were entropy in a closed system always increases; Open system dynamics are far more complex and difficult to formalise.

" Its line of least resistance, and everything falls to its lowest possible state. Life is that strange exception." ;-)