It's not an anomaly, a conundrum, or a fallacy, it's a PARADOX!
For time travel stories, my impression is that despite the different names, they all involve inconsistent causal loops, unless the multiverse is introduced. The difficult part of time travel paradoxes is to think out of all of the possible ramifications due to the circular nature of events.
Time travel links that describe types of Time Travel are after the spoiler section.
- 13 Aug- Primer and Time Lapse Added.
13Jul Loki Added.
- 12Jul21- Thread resurrected from Null Space.
- 12 Monkeys (1995)
- Avengers: Endgame
- Back To The Future (1985)
- Back To The Future Part 2 (1989)
- Deja Vu
- The Final Countdown (1980)
- Harry Potter And The Prisoner of Azkaban (2014)
- Jumangi (1995)
- Loki (2021)
- The Sound of Thunder
- Star Trek Next Generation: All good things.
- Star Trek Next Generation: Cause and Effect
- The Terminator (1984)
- Terminator 2: Judgement Day (1991)
- The Time Machine
- Primer (2004)- post 21 page 2.
- Time Lapse (2014)- post 22 page 2.
My take on time travel movies (spoilers)
- It’s intriguing, it can make for great stories, as long as they don’t go overboard. It’s best when they don’t make you think about it... too much.
- Traveling to the future has been proven by the theory of relativity, related to time. No paradoxes.
- Traveling back in time is much more problematic if the idea is you can travel both ways, especially if you do anything significant in the past and plan to go back to the same future, you left, because anything you do in the past will either change the future or split off the time line you are in, and you can’t go back.
- The Time Machine and The Sound of Thunder, based on a single timeline, are two outstanding examples of uncomplicated time travel.
- Back to the Future (single timeline) is good because it addresses the altered time line because of Marty McFly first disrupting his parents romance, and then the way he got them back together. When he comes back to the present, his family's circumstances have changed significantly in mostly a good way.
- Back To The Future Part 2 (1989)- Not as good as the first one. However they took the time to explain how time travel works, at least this version of it.
- Loki (2021)- gets my seal of approval for innovation. Who needs to worry about paradoxes when the TVA controls all timeline and can move between at will.
- Looper and Avengers:Endgame are problematic if you are looking for coherence, IMO.
- Interstellar has a significant paradox which I was able to overlook.
- Harry Potter And The Prisoner of Azkaban- Incorporates one of the most seamless time travel sequences into a book/movie. You watch the sequence with the end result, than you flip back and see what specifically happened. Two lives are saved.
- The Terminator and Terminator 2:Judgement Day- These movies are so good and there is no intent to return to he furture, it’s easy to over look the time paradox.
Spoilers follow, Time Travel Links follow that.
Movie Discussion (Spoilers)
The Terminator (1984) and Terminator 2 (1991)- These stories are so good, it’s easy to overlook the time paradoxes. The whopper in this story is that future John Connor sends back Kyle Reece to save this mother from Terminator assassination and Reece becomes his father!
Timeline (2003)- Exciting Michael Crichton story, the arrogance of a corporation, who plays fast and loose with people’s lives after they accidentally discover time travel trying to fax 3D package. There are elements of an altered timeline, and a bootstrap paradox.
The Time Machine (1960)- is easy to comprehend because the time traveler goes to the future, and when he comes back it’s a week later and he stays long enough to grab some tools and personal items, then returns to the future. As best as I can tell no paradox involved.
In the Back to the Future movie, the concept is easy to understand that if McFly does not get his parents together, he will cease to exist, by virtue of a fading photograph, which as I recall, a photo was used in both the 1st and 3rd movies. However what the movie does not address is all of the peoples' lives he has effected by interacting with them, other than the benefit to his own family. Maybe he inspired the "soda jerk" to become mayor. This is an altered timeline. Best not to think about all the changes that occured to Marty by virtue of the altered time line, and how he would mesh returning back to his now changed former life.
Back To The Future Part 2 (1989)- Not as good as the first one. However they explained how when old Biff gave the sports almanac to young Biff, it caused a tangent in the time line so things in the future where they were (2015) did not change, because a new timeline was created in 1955 with the handing over of the book to young Biff. The solution was to go back before the divergence and take the book back.
The fallacy with this time travel example is that they use this one event, knowledge of the future outcome of sporting events, as the only thing that would drastically alter the future, although cumulatively all of the changes caused by Marty going back, then the Professor and Marty going back and interacting with people, any number of minute things could drastically altered the furture, but hey, that gets too complicated fast and... it’s a time paradox.
The Sound of Thunder- One of the earliest time travel stories I am aware of is The Sound of Thunder, a 1952 Ray Bradbury story which is the origin for the term "butterfly effect", where a time traveler steps on a butterfly and the future is changed. Also a mediocre 2005 movie, about traveling back in time, to hunt dinosaurs. If I recall properly, dinos that we’re going to die anyway in a particular time frame, but you can’t stray off a designated elevated path. Things go wrong, a character strays off the path, and the future is dramatically changed. This is an outstanding take on time travel, and an altered time line because it illustrates that a small change in the past could produce an unimaginable change in the future you left.
In 12 Monkeys (1995), a character Cole is sent back in time to look for an organization called the The Army of The 12 Monkeys, an organization believed to be responsible for the outbreak of a deadly disease that wipes out most of humanity. However he arrives earlier than the target date, inquires, and inspires an inmate at a mental institution, which starts a chain of events. This would be a bootstrap paradox.
In Interstellar, I decided I really like this science fiction story because it‘s equal parts SciFi and an examination of human emotion in extreme circumstances, and what could be described as a perfect time paradox, a visual depiction of time as non-lineal and under certain vague hypothetical circumstances (a Tesseract) provided by advanced beings, (maybe advanced us), accessible at different points.
It also includes other vague plot points such as quantum data being transmitted from inside a black hole to help scientists on a dying Earth figure out how to create a gravity engine. But the important thing is that I was comfortable not focusing on hard technical, scientific details which are sparse and going with the story and accepting the narrative as presented. (Description updated, spoiler added (Aug 2021).
- The Earth is dying and must be abandoned.
- Cooper is a retired astronaut and now farmer watching his crops die.
- Murph, his daughter talks about a ghost in her bedroom.
- This “ghost“ sends them a binary message of geographical coordinates.
- Coop and Murphy drive to it and locate a secret NASA facility underground.
- …where Dr. Brandt an acquaintance of his, tells him about the mission to save humanity, Plan A relocate the humanity to another planet. Plan B is to take human embryos to another planet to get a fresh start. Brandt is working on technology to harness gravity as a propulsion force to power manned vehicles out of our atmosphere into space and carry humanity to a new home.
- Cooper the only one available with previous space mission experience volunteers to lead the mission.
- Convientently a worm hole appeared in the vicinity of Saturn 40 years ago. It is speculated that an advance civilization placed this worn hole for our use to provide a viable option for humans to relocate.
- Later in the story Coop finds himself in the Tesseract, a device created by 5 dimensional beings, which allows him to send a variety of messages back to his daughter.
- To solve the gravity engine equation, quantum data is required, that can only be retrieved from a black hole. Coop and his robot end up entering a black hole (not voluntarily), the robot grabs the quantum data needed. Coop uses the Tesseract to send this data via the Tesseract to his daughter through an identical wrist watch he gave her.
- Coop of the future sends himself the coordinates of the secret base which results in him leading the mission.
- Coop speculates that the advanced civilization who placed both the wormhole and the Tesseract, might be “future” us. The second paradox would be why would we have to save ourselves if we survived into the future Before this.
My favorite paradox occurred in Star Trek Next Generation series final All Good Things where Capt Piccard finds himself traveling through time, jumping back and forth in his life. This is another test perpetrated by Q. In the past, he becomes aware of a temporal anomaly close to the Devron System in the Neutral Zone and discovers that by virtue of being a temporal anomaly, it is moving backwards in time, growing as it moves backwards. His retired self vowes to cajole his friends into transporting him to the Devron System to look for it at an earlier state, searching by means of deploying a reverse tachyon beam. The cause of the paradox is that he is the one who causes its creation by looking for it!
Star Trek Next Generation: Cause and Effect- A brilliant episode.
The destruction of the Enterprise near a distortion in the space-time continuum causes a temporal causality loop to form, trapping the ship and crew in time and forcing them to relive the events that led to their deaths.
Jumangi (1995)- A favorite movie, no time travel, but creates a time line that is later erased when the game concludes. No paradox, simple to understand.
Looper- the worst time travel movie I've seen if the goal is to all most understand why things happened the way they did. Nine Problems With Looper.
Avengers: Endgame (2019)- This is a top rated fan film that not only features time travel, but shoves time travel in your face to undo a huge event, in a very specific way, as if you can go back and forth in time, but somehow not scrambling everything in the processi.
Six immensely powerful relics, are removed from the past, but somehow does not turn the future completely upside down, but manages to restore half of all life that was destroyed (which makes sense in itself, because Thanos used those stones to destroy that life, and he could not find the stones, because they were taken), have a big fight, then go back to the past, put the stones back and somehow that does not undo everything that the time travel changed. Bottom line: Just Don’t Think About It.
Deja Vu (2006) is an enjoyable Denzil Washington movie where a police officer travels back in time (about a week) to prevent a terrorist attack on a ferry carrying passengers and automobiles. Yes, there are now 2 of him, but the story is surpringly coherent.
Loki (2021) A Marvel/Disney time travel story that avoids the usual complications by having multiple time lines (if you go back in time and change something, it splits off into a new timeline), and the original timelines remains unaltered and includes the mysterious TVA.
- In the original Avengers at the end of movie, Loki is taken to Asguard by Thor and imprisoned and the Tesseract is stored away there.
- In Endgame, in an attempt to grab the Tesseract, Loki ends up escaping with it and ends up in the desert. This is Loki in a branching timeline, where the Loki series takes place.
- The solution for the Avengers in Endgame (the original timeline) is to go farther back in time to 1970 and grab the Tesseract there.
- Since the last Loki episode has yet to drop (when this was added) we don’t know if he stays in a seperate timeline or is somehow put back in our timeline because here, he is dead,
This will be the way to bring the Loki who escaped with the Tesseract in End Game back into our timeline resurrecting him by means of the “Time Keepers“ who manage multiple, parallel time lines, and can jump to any time line they desire with one of their time gadgets. That is the answer and my guess is this is how we will see Loki we know will rise once again in our Universe.
The Avengers' time shenanigans had one very important consequence that was not addressed at all
It hasn't been officially confirmed when Loki takes place in the overall MCU timeline, but a major clue has been discovered.
The MHM Podcast Network movie synopsis and film summary of The Avengers (2012) starring Robert Downey Jr., Chris Evans, and Scarlett Johansson.