How Nature Behaves: Making sense of patterns in the chaos.
Nature, on the whole, can seem pretty random. Yet simple patterns are everywhere in nature. Amazingly, they arise from very complex systems.
The patterns have been observed and analysed. Controlled experiments have been created to look more closely at the phenomenon. We can watch them happen in front of our eyes yet still be unable to understand how nature creates these patterns. There is something about the fundamental nature of the universe we still don’t understand.
Some of these patterns are responsible for the events and processes that create galaxies, planets, continents, coastlines, rivers, weather and life. Even us.
Evolution and Earthquakes
Evolution has a long history of being studied for its patterns. In the fossil record, there are times of very little change, and times of rapid change. Charles Darwin, the “father of evolution”, included these simple observations in his classic 1872 text “The Origin of Species”, crediting British scientist Hugh Falconer with first proposing the idea that stasis is more common than periods of change.
The name given by Niles Eldredge and Stephen Jay Gould in 1972 to this type of pattern is “punctuated equilibrium”. It simply means that the normal balance of nature sometimes shifts dramatically in a short period of time.
When earthquakes are analysed in great number, a simple pattern appears.
( View a graph of earthquakes comparing the number per year worldwide with their strength by visiting: http://img176.imageshack.us/img176/1092/quakesizegraphvs7.gif )
The bigger the earthquake, the less often it happens, but in a simple mathematical relationship called a “power law”. When an earthquake is 10 times larger, it happens about 10 times less often, and this relationship holds over a very large range of earthquake sizes.
The pattern in the patterns
Each example is of a complex system involving many individual interactions. Each has an input of energy that is gradual. Each has an output of energy in a pattern of events that follows a power law relationship. The release of energy keeps the complex system in balance.
In evolution, gradual input of mutations that builds up the variety of genetic alternatives (biodiversity) is reduced by extinctions. Pressure gradually built up by movement in the earth’s crust is released by earthquakes. The weight of snow gradually falling is released by avalanches. As the potential energy in a complex system grows, it reaches a maximum level. Snow can only get so deep before it slips off the mountain. Events following a power law pattern keep the potential energy in the system below this level.
These patterns of events in nature have been collectively dubbed “self-organised criticality”. This means a complex system organises itself into a balance the events that maintain the balance in a complex system are controlled by the system itself. Like earthquakes releasing pressure in a shifting earth’s crust.
Energy input: – Energy output:
Gradual potential energy increase – Punctuated energy release:
Mutations occurring – Extinctions
Snow falling – Avalanches
Electric charge build-up – Lightning
Earth’s crust movement – Volcanic activity, earthquakes
Sun’s nuclear reactions – Solar flares
Simulations
Scientists have created simulations to study the patterns that arise in complex systems, where the individual interactions obey simple rules, and adding all these together produces simple patterns.
Per Bak in his important 1997 book “How Nature Works: the science of self-organized criticality”, used the model of a sandpile, where a stream of grains was fed into the system from above, and avalanches of sand on the side of the pile were measured to observe a simple power law relationship.
It works on us, too
In 1932 George Zipf published a simple power law for the frequency of occurrence of words in any large text. He also noted a similar power law applied to the size of large cities (applies only in regions where there is no centralised planning).
Traffic jams, car crashes, stock market movements and many other human phenomena also seem to obey simple power laws. When the pacifist L.F. Richardson looked at the number of casualties in 82 conflicts between 1820 and 1929, a simple power relationship was found.
Richardson apparently concluded that wars were inevitable. Yet wars are simply the consequence of sovereign nations aggressively competing for resources against other nations. When global resources are managed by a global authority, there will be the same peaceful sharing as we see within nations where a single authority manages those resources.
It just leads to more questions
Why would these patterns exist? Is there a god or not? Is everything interconnected or not? Are such things as free will, randomness or coincidence real? Is self-organised criticality the mechanism behind the Gaia hypothesis, where life on earth is thought to regulate the environment for its own benefit? Certainly there is something going on in this universe. The question still is: “What actually is it?”
At least we can see very clearly that we are subject to the same rules as the rest of the universe. We are as much a part of nature as anything, and subject to the uncertainties of the universe. We can use this awareness to accept change as inevitable. We can pay more attention to steering and controlling that change, rather than fighting it in our lives as individuals and as a species.
Image Credits:
Earthquake frequency www.iris.edu
Simulation – http://www.calresco.org/
