The Butterfly Effect
In 1952, an author named Ray Bradbury published a short story called "A Sound of Thunder." In it, a hunter named Eckles pays $110,000 to travel with Time Safari, a time machine company that takes hunters back to the time of dinosaurs and allows them to hunt the T-Rex. The company guarantees nothing, neither your safety nor your return, and there are strict instructions and expectations for how the hunter should behave once they travel back in time.
When they travel 60 million years back in time, they notice the path that has been laid by the company. It floats 6 inches above the earth and is the only path that the hunter should travel upon. They cannot touch anything during their stay in the past, and they are only to shoot when told to. Interrupting any of the natural processes in the past could have irreparable repercussions for the future. Step on a mouse, and you leave your print like the Grand Canyon across eternity.
They're very careful with leaving the past just as it was supposed to unfold. The T-Rex that they were supposed to kill was going to be crushed by a tree only seconds later; it was going to die anyway. Eckles, however, is terrified and runs back to the time machine through the jungle and waits for the others. But once the rest of the crew returns, they notice the mud on Eckels's boots. Against their better judgment, they allow him to return with the crew back to present day.
When they exit the time machine, the crew checks in with the man behind the desk to see if everything is okay, and the man tells them it is. The man, however, is acting a bit different from before they left. There's a strange smell in the air—it's faint, but it's there. The sign on the wall is different; the words were spelled differently. Eckles sits down and checks every inch of his body for things he could have ruined, and on his boot, caked in mud, he finds a butterfly—beautiful and dead.
The death of a single butterfly has somehow resulted in the future being changed. He cries out in disbelief, begging to return to the past and somehow undo what he's done. He sits down with his eyes closed and senses a crew member enter the room.
Like big bombs, huge earthquakes, or other large-scale events, it has now been realized that this is a very old-fashioned view held by people totally out of touch with modern thought. The things that change the world are the tiny things. A butterfly flapped its wings in the Amazon, and subsequently, a storm ravages half of Europe. Paraphrased a little bit, this is a quote from a novel named "Good Omens."
What it's talking about is the butterfly effect. Sensitive dependence on initial conditions, more commonly known as the butterfly effect, is the idea that a small change in any situation could have huge implications later on down the road. The idea was coined by Edward Lorenz in the 1950s. Lorenz was a meteorologist who was searching for a means of predicting the weather.
He was conducting experiments with various numbers to try and model a weather prediction. He did a previous experiment with an initial condition of 0.506127, six significant digits— a little bit overkill, he thought. So this time, his initial condition was only 0.506, three significant digits should be fine. So he left the room to get a cup of coffee, and when he came back, he found something drastically different from what he had previously.
At first, things seemed normal, and they seemed to follow the first experiment one-to-one. But after a while, they started to diverge and looked like completely different models. A 0.03% difference in values had enormous long-term implications. It may seem insignificant—it's just a model, right? Well, Lorenz had actually just opened the door to a new way of thinking and seeing the world around us.
Chaos theory is the study of mathematics that focuses on exactly this kind of thinking, but its name is kind of deceiving. The butterfly effect doesn't represent chaos but rather the effects of changing the slightest conditions and then observing the results. Think of this: it is easier to predict the orbital period of a planet in another star system 10 million years from now than it is for us to predict our...