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Q & A: History and Statistics

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Most recent answer: 10/22/2007
Are there any statistical models for the decay of a country or do they consider the disorder too large for any long-term statistical model? Also, do scientists consider the butterfly effect to play a critical part on the actions of humanity?
- Patrick DeJarnette (age 16)
Allentown, PA, USA
I am skeptical about the application of statistics to the history of countries. One of the big problems here is that it is impossible to do controlled experiments, changing only one variable at a time, in order to investigate its impact on the future of a country. Furthermore, there is the trouble in defining just what is meant by "decay" or anything else. We can measure things like population, economic output, employmenht, saved wealth fairly reliably, but intangibles like international influence and any other things you might be thinking of that can decay are much harder to get a handle on.

Nonetheless, there is quite a large sampling of different civilizations which have come and gone over the millenia. Each one is different in its own way, with different geograpical and political environments, different technologies, and different internal structures. One can investigate samples of different countries over time to try to find correlations between factors and outcomes, but the results will usually lack the level of proof required by the scientific method. Sometimes it's pretty obvious what does a country in (say, a natural disaster can wipe out a small country, as is suspected of the Minoans and the eruption of Thera). Other times, it is a large collection of interrelated factors. You can read Gibbon's "The Fall of the Roman Empire" to find out all the kinds of things which caused that state to decay. Not all of these suppositions may be true of course, and one must read history with a mind that is simultaneously open and critical. One big problem with history is that it is written by historians, and historians often introduce their own ideas and cultural biases into their work, obscuring sometimes very important things.

I would suggest talking with your history teachers, and reading a variety of books on world history to find out about the large variety of countries that have come and gone over the ages.

The "butterfly effect" is a fancy name for the idea that the behavior of complex systems is very dependent on initial conditions, making prediction of future behavior difficult or impossible. The claim comes from people trying to predict the weather -- even a small disturbance in local wind patterns, even tiny ones as the flapping of a butterfly's wings, can affect weather patterns far in the future. This may be a bit of an exaggeration, but there are systems in which minute local variations can be magnified exponentially over time.

It's a way of saying that even small events can have a profound and unpredictable effect on future actions. I don't worry about this at all in the actions of humanity, though, since we have many stabilizing forces built into our behavior already. Most small actions don't have large-scale consequences because we automatically correct for things when they get out of whack (we put criminals in jail before they cause too much harm, we regulate prices in monopolistic industries, and the market system corrects much of human behavior on average automatically anyway). Some people may think the stock market flutters around randomly, but there are big forces at work behind stock prices, and while the prices really do have a random component to them, it is not because of small transactions but because of large ones. I wouldn't say the "butterfly effect" is all that important in the study of human history, but I could be wrong.


(published on 10/22/2007)

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