In Ray Bradbury‘s Dystopian short-story “A Sound of Thunder“, the protagonist Eckels takes a time-travel safari to the Dinosaur Age to kill a T-Rex. While hunting the T-Rex, Eckels steps on a butterfly. They come back to the present day (A.D. 2055 in the novel), and find out that history has been altered. A Fascist dictator now rules the city of Chicago, and rules of spelling words have changed.
While the novel is pure fiction, one can’t bother but wonder, how could stepping on a butterfly produce such a massive change in history?
The concept of the cascading effect of a seemingly insignificant action, or the “Butterfly Effect”, is discussed in the novel prior to Eckels and Travis, the safari guide, entering the time machine:
“All right,” Travis continued, “say we accidentally kill one mouse here. That means all the future families of this one particular mouse are destroyed, right?
…
Well, what about the foxes that’ll need those mice to survive? For want of ten mice, a fox dies. For want of ten foxes a lion starves. For want of a lion, all manner of insects, vultures, infinite billions of life forms are thrown into chaos and destruction. Eventually it all boils down to this: fifty-nine million years later, a caveman, one of a dozen on the entire world, goes hunting wild boar or saber-toothed tiger for food. But you, friend, have stepped on all the tigers in that region. By stepping on one single mouse. So the caveman starves … With the death of that one caveman, a billion others yet unborn are throttled in the womb. Perhaps Rome never rises on its seven hills. Perhaps Europe is forever a dark forest, and only Asia waxes healthy and teeming. Step on a mouse and you crush the Pyramids. Step on a mouse and you leave your print, like a Grand Canyon, across Eternity. Queen Elizabeth might never be born, Washington might not cross the Delaware, there might never be a United States at all.”
— Bradbury, A Sound of Thunder
In short, Bradbury takes the example of killing a mice, and uses it to argue that every cause has a greater effect. These effects beget even greater effects, and thus, a catastrophic chain reaction ensues. While the Butterfly Effect seems logical as Bradbury describes it, there are several gaping flaws with the theory.
The biggest flaw is that Bradbury assumes the food chain to be a linear, strictly-controlled pattern of predation. In other words, its assuming that every predator in the wild has only one species of prey, sort of like this simplified diagram of the food chain. When Bradbury mentions that “for want of ten mice, a fox dies”, he was implying that mice was the sole source of food for foxes.
In reality, the food chain is much more complicated. does not account for is the fact that a fox’s diet includes much more than just mice. Even if 10 mice were to die, the fox could find other sources of food, say insects or berries. Similarly with the lion, foxes are not its only prey. The food chain is much more complicated than Bradbury realizes. Very few animals rely on a single source of food, and all animals are able to adapt to changing environment and conditions. For want of ten mice, a fox will find something else to eat. It won’t just plop down and die.
Secondly, Bradbury ignores another way of nature that I like to call “dampening”. It is, in short, the diminishing effect of actions over time. Think of the phrase “time heals all wounds”. When something adverse happens, nature always has a way of restoring itself to equilibrium. After a volcanic eruption, new vegetation spurts from the ashes. After a tornado wipes out a town, residents return to the town to rebuild. All organisms, from the humble starfish to us humans, have behavioral and neurological “buffers” that protect us from calamities. Remember that time years ago when you got a paper cut? According to Bradbury, you would be in a coma by now. But no, you’re reading this blog because your body was able to heal itself from the paper cut.
Of course, a cultured scientist will say that one must test the hypothesis to validate or invalidate it. In the case of the Butterfly Effect, we can’t really test it out. There’s no way for us to crush and not crush a butterfly, or to inflict and not inflict a paper cut. We can only see one path through time.
Even if we could, though, it’s hard to determine whether events later in time are a direct consequence of an event that preceded. For example, let’s say you wake up 5 minutes before your alarm, and six days later a train crashes into a skyscraper. How can we link these two events using proven evidence? By Occam’s Razor (taking the path of least assumptions), we’d say the two events are not related.
If the Butterfly Effect is seemingly a long shot at a veritable theory, then why do people seem to believe it so much? I think part of the hype that surrounds this story stems from real news stories. I’m talking about stories like someone winning an election by one vote, or former president Theodore (“Teddy”) Roosevelt being saved from death by a Bible. It’s events like this that make us think, “Well what if three more people had voted in that election?”, or “What if Teddy never had that Bible?” By simple reasoning, we can say that history would be different if Teddy had never carried a Bible in his pocket.
Here, I make amends. Yes, major events in history such as mass extinctions and great speeches can and do leave their imprint on society. If Prohibition had never been repealed, then we probably wouldn’t complain of hangovers as much. If the dodo bird was still alive, then the creatures of Mauritius would have slightly different ecological niches. But these major events are not in the scope of the Butterfly Effect, which concerns only small and seemingly insignificant events. There is no denying that major happenings can change the world. It’s logical cause-and-effect. As for the small events, though, they won’t be sending apocalyptic shockwaves through spacetime anytime soon.