A Sound Of Thunder

Despite their best efforts to control the conditions of the trip, the hunting party causes a change that will have a ripple effect through time, leading to Deutscher’s election. The tightly controlled protocols and technological inventions that lead to a feat as impressive as going back in time are not sufficient to prevent Eckels from violating the rules out of fear.

Though Eckels is to blame for the particular action that led to changing the past, Time Safari is also to blame, with Travis freely admitting that they “do not know” and are merely guessing how time travel works. Time Safaris stresses the danger of changing the past in even tiny ways and demands extreme caution of their customers, but the company is toying with forces that they do not fully understand and making money off of it. This recklessness reveals Bradbury’s concerns about the potential for the overzealous, and ultimately destructive, use of technology.

Bradbury’s depiction of the time machine, the key piece of technology in this story, is both wondrous and menacing. As he describes its “mass and tangle, a snaking and humming of wires and steel boxes” (103), he implies that the object is chaotic, complex, and perhaps impossible to understand. Its noises are described as “screams” and “murmurs,” personifying the machine and adding to its menace. As Eckels sees it the first time, he marvels at it and excitedly prepares for his journey.

After his panic at seeing the T. Rex, Eckels takes shelter in the machine. This sense of safety is short-lived, however, as the hunting party returns with Travis extremely angry at Eckels. This suggests that the sense of safety that comes with technology is false, and that ultimately our actions, such as our harm to the environment, will catch up with us.

The culmination of this theme comes at the end of the story when Eckels kills the butterfly. The butterfly thus symbolizes all that Travis was trying to convey through his speeches—that small events can have an outsized effect and should not be tampered with. These ripple effects cannot be predicted nor prevented, despite Time Safari’s best efforts to do so.

Travis’s character is key to conveying this theme to the reader. As the trip leader, he is highly aware of the dangers of tampering with the past, and he explains this to Eckels and the other hunters through long descriptions of the domino effect. He uses the example of killing one mouse to describe the accumulation of cause and effect through time. By this logic, even tiny components of the ecosystem matter.

Bradbury compares Eckels and the Tyrannosaurus Rex by using similar language to describe their deaths. Both deaths are brough about with a sound of thunder. Bradbury seems to be pointing out the meaninglessness of certain "large" characters in the fullness of time. While Eckels is a rich, important person in his time, Travis kills him with little fanfare. Likewise, the dinosaur is the largest predator of its era, but its death doesn't even alter the passage of time. Conversely, the death of the smallest butterfly changes the course of history.