Last night, I quickly had a look at the weather forecast for today. It confidently reassured me that there would be a bright, sunlit morning with a 5% chance of rainy spells. Of course, I had no doubt in my mind that the forecast was telling the truth. In the morning, I awoke with a large yawn and a badly-needed stretch. As I got up to draw back the curtains and admire the sunshine, I felt a sharp chill creep up my spine. “Hmm, it’s oddly cold in here”, I thought. Throwing back the curtains in vivid anticipation, my eyes flinched at the glare. My garden was covered edge to edge in a thick layer of bright, white snow. Just as predicted, right?
If you’ve used a weather forecast, you’ll know that those things generally aren’t very accurate. They might get it right for a subsequent few days, but predicting any further is like trying to figure out who will win a presidential election – it’s impossible to know. You might think that in an age where we have the ability to send other humans to the far reaches of space (the Moon’s pretty far, shush) and take pictures of galaxies and stars on the other side of the universe, that we’d at least be able to have a full grasp of something as seemingly trivial as our own planet’s atmospheric fluctuations. But, in fact, understanding the Earth’s weather system is one of the most challenging problems humanity faces, and perhaps will ever face. This is not because there’s any particularly exotic or unfamiliar forces of physics involved, but it comes down to one simple, or perhaps not so simple, idea – chaos.
Chaos is something that is intrinsic in many natural dynamical systems, of which weather is the prime example. It is such a pure field, fundamental to understanding all patterns and complexity in our universe, yet it is often treated as the neglected third child in the family of modern theories, its siblings being the widely loved and adorned quantum mechanics and relativity. The quantum delves into the weird phenomena that take place on the smallest scales whereas relativity observes the largest astronomical bodies in the universe. Both of these theories, along with all other traditional science topics, deal with supposedly predictable phenomena. In the case of quantum mechanics, even though the physics is non-deterministic, the fact that randomness is inherent allows us to make probabilistic predictions.
On the contrary, chaos theory is in itself the study of unpredictability in systems that are impossible to predict or control, like weather, the stock market, or even our own brains. It is the observation of patterns and stability in these systems which display infinitely messy complexities – chaos and order are simply two sides of the same coin. It exists in our world mutually, not in some intangible quantum realm or unreachable galaxy, which is why its understanding should be of utmost priority. Edward Lorenz, a significant pioneer of chaos theory, summarized it in one sentence.
Chaos: When the present determines the future, but the approximate present does not approximately determine the future.
This has been a preliminary introduction into the world of chaos. Be ready for lots more to come.