Primer (movie)

Primer is an American science fiction drama movie. It is about friends who accidentally discover a way to time travel. The movie was released in 2004.
Shane Carruth, who made the movie by himself, also plays the starring role, because he could not find anyone else to do it. Some of his family members and friends are also in it. The only actor he hired was David Sullivan.
"Primer" has a confusing plot. The dialogue is difficult to understand. Carruth decided not to make the language simpler for the audience. The movie won the Grand Jury Prize at the 2004 Sundance Film Festival. It then played in a small number of theatres in the United States. It is also available on DVD. It is now popular as a cult movie. People still talk and write about how to figure out the plot.
Plot.
Four engineers, who are friends, work together during the day. At night, they run a side business from Aaron's (Shane Carruth) garage. With the money they make, they do research for their own inventions. Two drop out after an argument over what to work on next, leaving Aaron and Abe (David Sullivan).
Aaron and Abe work on a machine that will make an object weigh less. This would happen by changing the effects of gravity. The machine seems to work as planned, but it has a side effect. An object ( a Weeble) left in the machine uses 1300 times the amount of time the machine was turned on for. Abe thinks that objects inside the box travel over and over, from the time the box was turned on to the time it was turned off.
Abe secretly builds a machine large enough to put himself in. After using it to go back in time to earlier that morning, he proves how it works to Aaron. Abe and Aaron build another machine so they each will have one to travel in. Abe and Aaron start using the time machines to make money in the stock market. After a while, they get riskier with their travels and begin to try to change other events.
Thomas Granger is the father of Abe's girlfriend Rachel. Somehow he discovers that the time machines exist. He time travels, but because he does not do it correctly, he ends up in a coma. Aaron thinks that, at some unknown time in the future, Granger entered the box (for unknown reasons). This changed the timeline in bad ways. Abe is frightened by this and decides that time travel is too dangerous to keep doing. He tries to stop his past self from using the machine any more, so he won't get any bad effects. He uses a "failsafe" machine, which he had already built secretly and kept running in a hidden location. He travels back farther in time than his first trip (four days) and before he had told Aaron about time travel. He thinks this will repair any problems.
But, Aaron had found out about this failsafe box and used it to try to get control of the timelines for both of them. Meeting at a park bench, Aaron shows Abe that he has been using a recording to say their conversation from an earlier time to fool him. Aaron says he fought and was drugged by an earlier double (or copy) of himself, who used the failsafe to come back and make the recordings. This Aaron wants to travel back in time to undo the events of a party. A party crasher had tried to shoot Rachel Granger. Abe agrees to try to change the events of the party with Aaron. The two succeed, but it is not clear how many times of travelling back it takes.
Now, Abe and Aaron no longer trust each other, so their friendship is ruined. Aaron and Abe fight. Abe warns Aaron never to return or interfere with their doubles. Abe stays behind to continue to try to keep the original Abe and Aaron from ever using the machines for time travel. Aaron travels to France by air and begins to build a room-sized time machine with a group of workers there.
Making the movie.
Carruth has a college degree in mathematics and worked as an engineer. While writing the dialogue, Carruth studied physics, so the conversations would sound real. He used the short phrases and jargon that scientists use when they are working. The time machine itself is a plain gray box. It has an electronic "hum" made with a mechanical grinder and a car engine. The movie was shot in industrial parks and little houses in the suburbs.
"Primer" was filmed near Dallas, Texas in 2001. The scenes in the public library where Abe and Aaron made their Internet stock trades were shot in the Richardson Public Library. The time machines were running in a storage facility. An airport scene was shot before the September 11 attacks in the United States. This is why the scene shows barely any security. The actors are allowed to walk to windows to watch planes leaving.
The movie was made for only $7,000 US and a crew of five. Carruth decided to play Aaron himself after having trouble finding any actors who could "break ... the habit of filling each line with so much drama". He also did all the production work on the movie, including writing the music.
After the movie was made, Carruth took two years to edit "Primer". He said he found this so difficult, he almost gave up several times. The movie was first shown to audiences and judges at the Sundance Film Festival in 2004.