Finding Order in Chaos
In today’s podcast, I talk about Chaos Theory, because of the unpredictability of our current COVID-19 situation. Oftentimes, it helps to know the statistics, or even better, it helps to have an idea about the future situation. That’s where math comes in!
As we enter into the month of April, we approach the birthday of one of the greatest mathematicians to contribute to this concept of chaos. His name was Henri Poincaré and he was a French mathematician. In 1887, he entered a math competition. In this competition using Newton’s equations, he had to describe the position of three planets in the Solar System at each past and future moment of time. In a two-body problem, if you have two objects in a solar system interacting through gravity then using Newtonian equations you can predict the outcome of these two bodies. However, the particular problem that Poincaré needed to solve involved three bodies. Hence, it was a three-body problem.
What’s cool about this problem is that he didn’t actually solve it but he won the competition by pointing out that the system had too much unpredictability. Poincaré wrote, “It may happen that small differences in the initial conditions produce very great ones in the final phenomena. A small error in the former will produce an enormous error in the latter. Prediction becomes impossible.” In other words, because there are three bodies interacting with each planet’s gravity, there is no solution. This was the beginning of Chaos Theory.
So let’s fast forward to the year 1961. Dr. Edward Lorenz, a mathematician and meteorologist at MIT was working with an early computer, a royal McBee LGP 30, and he was simulating weather patterns using a computational model. In these weather patterns, he had 12 different variables that represented a variety of elements of weather, like temperature, pressure, wind speed, humidity, precipitation, etc.
He would put in certain numbers for certain variables and run the calculations to see what the weather patterns could do. On one particular day, he was intrigued by the output that he was getting. He decided to repeat the calculations that he was putting in, however on the second run he change the initial conditions. Instead of using his numbers from his previous initial condition, he used the numbers that his computer spat out from the middle of the run.
The data that he used was from the printout of the previous run. However, the data was a little different. That is because originally he had input six decimals, but the second time he was inputting data with only three decimals. The reason why is because the data that the computer was printing out was only to three decimals. He was using these values with three decimals as his initial conditions in this second run, unlike the six decimal figures he was using in his first run. He was expecting to see similar results the second time around. However, the climactic predictions had a completely different route.
After Lorenz determined that it wasn’t a mechanical failure in the computer, he realized that it was the small changes in the initial conditions, specifically the three decimal difference, that led to significantly different results. So, in other words, he came to the same conclusions that Poincaré came to 74 years earlier, which is that the small difference in the former produced a difference in the latter. This was another step in Chaos Theory. Lorenz referred to this as the Butterfly Effect. The analogy behind this was that one small incident can lead to a huge impact in the future. The Butterfly Effect was a term he coined in his presentation to the American Association for the Advancement of Science in 1972. The following download is his presentation.
No doubt, chaos is in everything and is everywhere, even among the human species. It’s even in our stock market. You see, in our stock market, chaos becomes evident when there is feedback. When the stock market goes up or down, people will buy or sell stocks. This process of feedback affects the prices of the stocks, which thereby leads people to buy or sell their stocks, and over and over again. This loop of feedback leads to a chaotic structure with unpredictability. That is why the stock market is so unpredictable.
However, despite this unpredictability, chaos has a sense of order that we can find in fractals. To put it simply, a fractal is a pattern that repeats itself on a large scale and on a small scale.
We see fractals all around us! In nature, with the repetitive shapes in the leaves of the plants and trees, in the lines in the tree trunks, in our coastlines…fractals and the foundations of mathematics surround us everywhere in nature.
Though finding patterns in chaos sounds counterintuitive, they are there, and they happen when you have attractors. An attractor is kind of like an evolved state that the system gravitates towards. A common analogy is if you were to drop a ball into a canyon. Ultimately, the ball would land at the bottom of the canyon. The bottom of the canyon is the attractor.
In a dynamical system, which can have many attractors, the system, though chaotic, will ultimately incline toward a repetitive pattern.
When Lorenz was conducting his simulations, he ran his numbers repeatedly with slight variations. With each variation he found that the weather simulation never carried out the same exact patterns, however the paths were close. In other words, even though the weather patterns were not exactly the same, they were similar and settled toward a pattern. Why? Because that particular system preferred a certain set of states. It had attractors. Thus, even in Chaos Theory, there are default patterns created in the system because the system has an attractor.
So, if you’ve never knew about Chaos theory before, you just learned the basic principles of this wonderful theory that helps us understand chaos. Those principles are
- Unpredictability
- The Butterfly Effect
- Feedback
- Fractals
- And Order and Disorder
What is most mathematically wonderful about Chaos Theory is the reminder that we can find ordered structures in the chaos that surrounds us. These structures are actually the mathematical tools that we use to find order. These tools are constructed on two primary and exciting ideas:
1. That even in a complex and apparently disordered system, we can find an underlying order. And…
2. In a complex system, because of the tiny differences in the initial conditions, the long-term outcome cannot be predicted.
As a result, though things may seem chaotic and unpredictable, there is comfort in knowing that the mathematical laws of nature will help us find order in this sea of chaos!
Until next week, carpe diem!
Gabrielle