Chaos

Edward Lorenz died a couple of days ago. If you thought that the only contribution a meteorologist could make to the world was reminding you to take an umbrella to work, Lorenz is proof otherwise. You've probably never heard of him, but you're aware of his work. Here's a short version of the story:

Lorenz was running a weather simulation programs on a computer. At one point, he wanted to take one of his earlier simulations and re-run it for a longer period. This was 1961 and computers were pretty feeble, so he had to reenter all the data. A couple days into the simulation, the weather pattern of the 2nd run diverged and took a completely different pattern from the first. It should have been identical. In trying to find out why it wasn't, Lorenz re-checked his numbers and found that the printouts he used to re-run the model had rounded the data to 3 decimal places, while the original data input was to 6 decimal places. Even though the change was less than .1%, this was enough to completely change the results (there's a rounding lesson in here, BTW). Further exploration led him to postulate the so-called "Butterfly Effect," that it was impossible to accurately predict long-term weather because a butterfly flapping its wings in Brazil could ultimately lead to a tornado in Texas.

These findings led to an entire area of scientific exploration called chaos theory. Aside from demonstrating that it would be impossible to accurately predict weather (you'd need to know an infinite number of inputs simultaneously), it extends to any complex system (so pretty much everything in nature) in that small changes can cause significant and unpredictable results.

So if you think your life is chaotic, this is the guy you can thank for it. Not really, but if we wonder why it's so hard to really understand relatively things, Lorenz is one of the people who can give us insight.