What is the butterfly effect?
Finally, the cool, rainy days are over, and I can enjoy the first days of early summer with Mika. That’s why, Mika and I want to go for a walk in the park today and get some ice cream. Last night, I heard on the radio that the weather is supposed to be really nice, with lots of sunshine and the weather should finally get warmer again.
As we were about to leave, Mika told me, “Four days ago, the radio forecast said it was going to rain and storm all day.” That made me think, and I asked, “Do you know why the weather forecast changes so often?”
“Hmm… have you ever heard of the butterfly effect?” Mika asked. When I said no, Mika told me, “The famous meteorologist and physicist, named Edward Lorenz, once gave a well-known lecture on the topic: ‘Can the flap of a butterfly’s wings in Brazil set off a tornado in Texas? ‘ “
Of course, this can’t actually happen in real life. As many butterflies can flap their wings, but it wouldn’t cause a tornado. What Edward Lorenz actually meant was that small changes to an initial situation can have a large long-term consequence. This knowledge is primarily applied to meteorology. For example, if you want to determine the weather for the next day, you take many measurements and then use powerful computers to calculate a weather forecast (You can read about that here).
If you now make a very small change to the initial value, you’ll notice that at first there are no real differences compared to the correct calculation. But after a short while, there will be small differences, and after a long time, you won’t even be able to see any similarities to the correct calculation. This is called the butterfly effect.
But the question remains: why does the weather forecast change so often? The problem is, it’s impossible to predict the weather in advance precisely. The measurements meteorologists gather are often not precise enough to forecast the weather for several days in a row. Even the smallest changes in humidity or wind speed can lead to significant weather changes. That’s why forecasts often change again.
“Now you know you should recheck the weather report before you plan to do anything.” said Mika. And we enjoyed the remaining sunshine and were happy that it hadn’t rained after all.
Text & Image: Amrei Konrad, Illustration: Patrizia Schoch