What are the external and internal conflicts in "A Sound of Thunder"?

"A Sound of Thunder" by Ray Bradbury is a quick moving, suspenseful short story. Conflict adds tension to any short story, and this one is no exception. There are four types of conflict:

External

1. Man Vs. Man -- During their trip back in time, Eckels panics when he sees the dinosaur and steps off the path, a huge mistake that could alter time. Travis, the tour guide, is furious with Eckels and threatens to leave him back in the past. He states:

"Stay out of this!" Travis shook his hand away. "This fool nearly killed us. But it isn't that so much, no. It's his shoes! Look at them! He ran off the Path. That ruins us! We'll forfeit! Thousands of dollars of insurance! We guarantee no one leaves the Path. He left it. Oh, the fool! I'll have to report to the government. They might revoke our license to travel. Who knows what he's done to Time, to History!"

This Man Vs. Man conflict adds tension between the two main characters of the story and adds to the suspense the reader feels as to what they will find when they return to present day. 

2. Man Vs. Nature -- This is the conflict that Eckels feels with the dinosaur he encounters in the past. It is huge - far bigger than he expected and he loses his nerve. Aside from the physical battle between the men and the dinosaur, this conflict also overlaps with Eckels internal conflict, man vs. self. 

3. Man Vs. Society -- This conflict is what makes the novel interesting; it begins as a sort of backdrop, seemingly unimportant, but by the end of the novel, Eckels' worst fear comes true and Deutscher is President. At the beginning of the story, Eckels states:

"Makes you think, If the election had gone badly yesterday, I might be here now running away from the results. Thank God Keith won. He'll make a fine President of the United States." "Yes," said the man behind the desk.

"We're lucky. If Deutscher had gotten in, we'd have the worst kind of dictatorship. There's an anti everything man for you, a militarist, anti-Christ, anti-human, anti-intellectual. People called us up, you know, joking but not joking. Said if Deutscher became President they wanted to go live in 1492. Of course it's not our business to conduct Escapes, but to form Safaris. Anyway, Keith's President now.

This sets up another external conflict that reappears again at the end of the story. 

Internal

4. Man Vs. Self -- This conflict is really the turning point of the story: Eckels loses his nerve and panics, veering off the path and rewriting history. When he sees the dinosaur, he states:

"Get me out of here," said Eckels. "It was never like this before. I was always sure I'd come through alive. I had good guides, good safaris, and safety. This time, I figured wrong. I've met my match and admit it. This is too much for me to get hold of."

He has a moment of realistic observation when he sees this dinosaur and is legitimately frightened. His veering off the path is what causes the change in the future. 

Can you provide an example of external conflict in "A Sound of Thunder"?

Internal conflicts occur within the character's own mind. For example, wrestling with a moral decision or facing fear are kinds of internal dilemmas a character might experience. External conflicts are often categorized as man vs. man, man vs. nature, man vs. supernatural, man vs. technology, and man vs. society. 

Ray Bradbury wrote "A Sound of Thunder" in 1952. The setting is 2055, and the premise of the story is that a man named Eckels is going back in time to hunt a Tyrannosaurus Rex. One of the external conflicts is man vs. nature, which specifically is the hunting of the dinosaur. 

"Some dinosaurs have two brains, one in the head, another far down the spinal column. We stay away from those. That's stretching luck. Put your first two shots into the eyes, if you can, blind them, and go back into the brain." 

Another external conflict occurs as a man vs. man conflict between Eckels, the protagonist, and Travis, the safari guide. Eckels is shocked at the sight of the dinosaur and doesn't have the courage to take a shot. In his fear, he compromises the entire mission. He is told to return to the time machine, and in doing so, he steps off the path. Travis wants to leave him in the past for this egregious error. 

"'Get up!' cried Travis. Eckels got up. 'Go out on that path alone,' said Travis. 'You're not coming back in the Machine. We're leaving you here!'"

A third external conflict is man vs. society. Travis explains that the government doesn't want them conducting time travel expeditions because the consequences are too grave. If anything is disturbed in the past, it can create ripples that change history in inconceivable ways. In order to operate, the company has to pay the government "big graft" (bribes). Travis tells Lesperance the consequences of Eckels's carelessness: 

"This fool nearly killed us! But it isn't that so much, no. It's his shoes. Look at them! He ran off the Path. That ruins us! We'll forfeit! Thousands of dollars of insurance! We guarantee no one leaves the path. He left it. Oh the fool! I'll have to report it to the government! They might revoke our license. Who knows what he's done to time, to history!" 

After Eckels begs them not to leave him and the group returns to the present day, they find that society has indeed suffered as a result of Eckels's actions. Instead of Keith being president, a tyrant holds the office. All of society has been affected negatively by Eckels's failure to follow the rules and the warnings. 

The most obvious external conflict is man v. nature, illustrated by the killing of the dinosaur by going back to prehistoric time. The two Time Safari staff members use their time machine to take three hunters to the exact spot where a Tyrannosaurus rex will be their target. And when it arrives on the scene, it bursts into view with “a sound of thunder,” because it of its size and power. It creates an immense external conflict, which is successfully resolved, though with much blood spilled.

Another external conflict occurs between the hunter Eckels and the group leader Travis. Travis insists on all rules being followed, and Eckels questions the reasons why. Then Eckels is so traumatized by the dinosaur’s appearance that he stumbles back to the time machine and steps off the path. Travis is furious, and with good reason, as it turns out. The outcome of this particular conflict changes all of their lives.