Tree House of Horror X - S11-E4
Trivia: People in line for the Exodus to Mars are: Bill Gates, Ron Howard, Jimmy Carter, Stephen Hawking, Mel Gibson, Paul McCartney, Michael Jordan, Stephen Jay Gould, Michelle Kwan, Mark McGwire and Professor Frink.
Trivia: When Homer finds out that the seat at his workplace is sleazy, he draws out a hate list to include "Econosave" office furniture on it. Items on Homer's hate list are: Bill of Rights, Grampa, Fat Free Lard, Gravity, The Emmys, Darwin, H2Whoa!, Billy Crystal, God, Soloflex, The Boy, Stern Lecture Plumbing, EconoSave.
Trivia: When Willie punches Professor Frink, look at the picture of Chewbacca on his shirt. If you look carefully the eyes on it move.
Trivia: At the end of the episode, when Uptown Girl has finished playing, you can hear Homer mutter under the song, 'I buried Flanders'. This is a Beatles reference as in one song John Lennon sang Cranberry Sauce and many fans misconstrued it as 'I buried Paul', as there was a rumour at the time that Paul McCartney was dead and had been replaced by a look-a-like. It's a very slick reference.
Trivia: The techno music that plays when Lisa runs is lifted straight from arty-German film 'Run Lola Run', which this episode directly mimics, in which we follow a race against time in the life of Lola, with three different versions of the day, with subtle differences leading to massive consequences. The music is played while Franka Potente (Lola) runs, as Lisa does.
Trivia: The Simpsons has a joke that has been run many times in different forms. They make a reference to the movie "Ben Hur", a movie about a Roman Gladiator. It has a famous chariot scene where one of his opponents has a chariot with spikes on the wheels. He uses it to cut up his opponents wheels and make them crash. This joke is frequently used in the show. It can be seen in the episode where they go to New York, where Bart makes a Soap Box racer, and many others.
Tree House of Horror X - S11-E4
Trivia: The people on the rocket to the sun are: Tom Arnold, Pauly Shore, Ross Perot, Dr. Laura, Spike Lee, Dan Quayle, Courtney Love, Tania Harding, Al Sharpton and Rosie O'Donnell.
Kamp Krusty - S4-E1
Trivia: James L. Brooks, the executive producer, was so enthusiastic about the episode's premise that he wanted to make it the official Simpsons movie. This idea was abandoned because the writers had problems getting the story to 23 minutes, let alone 90 minutes.
Trivia: In Season 18 Episode 18 (Boys of Bummer), the announcers at the ball game are an American from KBBL radio and a Mexican from QUE BBL radio. QUE is pronounced "K" in spanish.
Treehouse of Horror XIII - S14-E1
Trivia: In the sketch where Homer clones himself, when he leaves the clones out in a cornfield and they learn to clone themselves, the camera pans right and amongst all the clones we see Peter Griffin, a character on the animated show Family Guy.
Home Away From Homer - S16-E20
Trivia: When everybody is outside Ned Flanders' house, when Ned says something about soggy bread, you can see Krusty, but without his make-up.
Trivia: In this episode, Lisa mentions that it's the 300th time that Homer has gotten into trouble, and Marge says 'I could have sworn it was 302'. This is a reference to the fact that this episode, the one heavily publicised as the 300th episode to air on TV, was actually the 302nd due to scheduling problems. "The Strong Arms of the Ma" was the actual 300th.
Trivia: When Bart smashes his piggy bank for money, you can see that there are already cracks and tape on it. This is a reference to "Homer's Odyssey" where Homer smashed Bart's piggy bank when he was desperate for beer money.
Tree House of Horror II: A Simpsons Halloween - S3-E7
Trivia: In the shot of the house during the opening credits, a group of trick-or-treaters walks past. This is the same group that goes trick-or-treating in "It's the Great Pumpkin, Charlie Brown" (1966).
Thirty Minutes Over Tokyo - S10-E23
Trivia: During the flight to Japan, Marge reminds Homer that he had seen the Japanese movie "Rashomon" and had liked it, to which he responds something like "I don't remember it like that". This is a reference to that very movie, in which a number of people witnessed a murder and each gave a very different version of the events after what each "remembered".
Answer: I'm not sure if this is the one you're thinking of, but an episode of "Ray Bradbury Theatre," called "A Sound of Thunder," dealt with a similar matter: a group of hunters travel back in time to hunt dinosaurs, only to find things have changed when they get back because someone stepped on a butterfly.
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