Archive for January 29, 2010

Irreversibility in Complex System: 01

January 29, 2010 4 comments

If given the choice, many people would like to live in an unchanging world. However the world, indeed the universe itself, changes and often takes directions that people do not like. While the desirability of living in past eras is debatable, many would like to somehow ‘reverse the clock’ and live in some era when people like them supposedly had a better life.

There is one major problem with that wish, namely:

Complex systems are not reversible, and they cannot reach an earlier equilibria (or anything even close to that).

Before we delve into the ‘why’ of irreversibility, let us define some concepts. So what is a complex system anyway?

I prefer to define a complex system as one in which the number of components, or their interactions, cannot be determined with any degree of certainty.

Therefore a rifle firing match grade ammunition is far closer to a simple system than a complex one. Let me explain.. We can create and manipulate metal, explosives and machines with an extremely high degree of confidence. It is also possible to compute the effects of gravity, wind and altitude to a degree allowing them to be factored. So while a good rifle can still fail, miss or jam, such occurrences are tractable and correctable. It is possible to hit the target with the 5th shot, even if you missed the 4th because of bad firing technique, after successful hits with the first three.

Complex systems either have many components that are poorly understood, unknown or whose interactions are not well characterized. An additional factor operating in complex systems is emergent phenomenon. Living Organisms, Cultures, Nations, Civilizations are easily understood examples of complex emergent systems.

Let me start with a few examples derived from living organisms:

While fish and some amphibians have gills, aquatic reptiles or mammals (either alive or extinct) never redeveloped gills. Mosasaurs, Plesiosaurs, Crocodilians, Aquatic Birds and Cetaceans would benefit from the ability to extract oxygen from the water like fish. But in each case adaptations were made in existing systems rather than evolve gills again. Considering that animals rarely lose genetic material altogether, it is paradoxical that inefficient solutions such as air sacs, better tolerance to hypoxia and blowholes were preferable over regression, even for truly aquatic genera like some prehistoric aquatic reptiles (mosasaurs) and cetaceans (whales/dolphins).

The answer to this question underlies the main reason why complex system are not reversible, and is paradoxically also the reason behind the success of x86 based CPUs.

The simple answer is: compatibility of existing applications. You see, both evolution and CPU architecture are constrained by the inability of older or newer de novo designs to run routines that were developed for the system in question (and which are poorly transferable to older or brand new architectures). Every new feature implemented in an existing system or architecture makes it harder and harder to revert to the ancestral forms. It is easier to add new routines to emulate a desirable feature, even if the result is mediocre than revert or go back to the drawing board. In living systems, the drawing board approach is especially problematic.

Changes in our civilization present a similar problem. You cannot uninvent birth control pills, electricity, automobiles, flush toilets, the internet and universal sufferage. These concepts (and technology) have diffused and any group which gave them up first might be at an disadvantage to one that did not. Though each innovation creates its own problems, many routines our world depends upon require their continued presence. Moreover many innovations, such as nuclear weapons, are game changers in that a world with many nuclear powers is very unlike a world with one or two nuclear powers. The mere presence of a few crude nukes can change the bargaining posture of larger nuclear powers, because such weapons are far more damaging to countries that depend on more complex and interconnected systems and supply chains to maintain high productivity than those who do not have them in the first place.

There is no way back, and even a collapse will give us a world that is unlike one that we have ever lived in. Many aspects of our age, such as top heavy demographic profiles, widespread diffusion of technology, near instantaneous communication on redundant networks and widespread technological diffusion have no historical precedent. Consider the effect of digital cameras in cellphones (barely a decade old) on aspects of our lives such as news reports, multiple records of incidents and teenage girls sexting their ‘boyfriends’. An innovation as cheap and small as fixed focus digital cellphone cameras has changed our world in ways that we have still not fully appreciated.

Everytime, we open a few new doors we close an old door for good. It is not intentional, but inherent in the very action of opening new doors. These new doors open up possibilities that are far more lucrative than retracing your steps and giving up the new possibilities.

Evolve or Die, Your Choice! If you choose to keep practicing old behaviors with negative survival value in this world, do not blame others for your demise. An ape mind with trans-human capabilities will kill itself, eventually. What worked for most of human history may now be counterproductive. It is important to be aware that a lot of “ingrained” behavior is actually choice, even if it is not evident at a conscious level.