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Physics/Time-Travel problems


QUESTION: Good morning,

I have a question. It is honestly home-work related but in a more unusual and complicated way because it's been hard to find an answer. We really hope you could shed some light or even recommend any resources to refer to.

My friend is working on a story for her writing class. As it's a writing class, most of the work they do is practical application since things such as quizzes and exams aren't as useful as opposed to projects and assignments are. So this project is worth 60% of her grade since it's going to be a full-on assessment to see what all elements and knowledge she's picked up in this course and if she's eligible to take on the advanced part of this topic for the upcoming academic semester.

Her writing is brilliant. Her biggest concern is on how she's representing events in her story instead because it involves time-travel and I've posited a lot of questions that have riddled holes in her story.

The premise is set sometime in a very distant future. The hero is a bright girl who has recently graduated from a militant based academy. Her dream has always been to be part of the Time Force, an official organization started up by the governments of the world.

Their goal is to basically manage time. They are responsible for keeping track of events, and making sure major/important events happen accordingly and do not string off tangent. If anything happens to go slightly askew, such as Amelia Earhart never disappearing, their job is to make sure the original event take places.

It's a pretty interesting set-up, and her story is great. I really enjoyed it. That aside, however, there are several problems in her story.

If we can believe for a moment that time-travel to the past is achievable...

How are they able to run their organization, honestly? If an event was supposed to happen but then suddenly it doesn't then wouldn't the original happening of the event itself be re-written and be remembered as that instead?

Like if World War II did not happen like it was meant to, then wouldn't History originally remember it as never occurring? How exactly are they keeping track of this in their database? How is their database not riddled with false information or changes then if things took on a different twist? What exactly is making their database so fool-proof and allegedly accurate?

Also, how are they keeping track of everything and making sure a slip-up doesn't occur after fixing it? For example Team B has to go back in time to help Lewis Carroll write as well instead of choosing to only become a photographer through and through. After helping him, how can they be sure that a hiccup doesn't occur again and then Team C is sent to address that issue or that Team B has to stay around to make sure Lewis Carroll doesn't do the opposite of what he's meant to do? And on that note, if they're supposed to go back in time to correct that mistake then doesn't that mean the mistake never existed since they went ahead to fix it?

Any and all theories or recommendations you can put forward is deeply appreciated.

The reason she's so worked up on this part of the story is because it will be part of what she's graded on.

The ultimate focus of project is on the writing itself for which she'll be graded on, like character development, voice, tone, writing style (all of which she's done very beautifully). In addition to this she's also meant to write a mini-essay about her story, the point of which is to see both how well she presents her premise and how much time and effort she's poured into her project. So the short essay will essentially focus things such as why she's written this specific story, citing and explaining what resources and references and inspirations she's used to help develop her project, how she's presented her story and what makes her story work.

So, to re-summarize, my friend is trying to work-out the holes in her time-travel story. Any ideas?

Thank you for your time

ANSWER: First, you can use the first-person narrative if it's your project and not "your friend's" project.  Second, suspension of technical details is a cornerstone of fiction writing.  That said, let's get to the science/storyline.  They are intertwined, thankfully, I have a degree in English that was focused on writing and linguistics more than literature.

This is a classic storyline, straight out of Star Trek Voyager and Star Trek Enterprise.  If you can travel in time in the traditional sense, then you can theoretically set yourself apart from the timeline, like a splash of water going upstream and altering the flow pattern.  Then perhaps you can establish a temporal "chain of command," in which you pass events back up the timeline and be independent in your operations.  It's the biggest headache in time travel, don't wrap your head too much around it.  

Most physics theories posit that you can't send a physical object back in time easily, but information is a different thing.  Murky area, where writers work with science.  In theory, you can create a time machine that will take matter and information back in time...but not before the machine itself was created.

I hope I gave you a start, but follow up...I looove time travel questions and debates.

---------- FOLLOW-UP ----------

QUESTION: Hey Steve,

Hahaha! I really wish it was me doing the writing course as this is a subject I really love <3 Instead, I pursued my masters in teaching...another subject that I do love too, but I digress.

I've been thinking about her story some more, and I've had a couple of ideas but I haven't approached her yet because I want to make sure I give her something that would help her instead of dig herself into a metaphorical hole.

There are two things that I think _might_ work. The first is to slightly alter the way the Time Force works. I think their main objective should be to make sure that their organization continues to exist given that their job is to keep History as we accurately remember it. The reason for this thought is because there will surely be people interested in infiltrating their base of operations in the hopes that they could change certain events in History to better suit their objectives. So their job is to essentially make sure no one misuses the time machines or tries to undermine their work.

Second, I considered the nature of the database itself. The best idea I can come up with is this: it is not simply a bank of information that records what has happened over time but also carefully lines out and explains all that surrounds the event. Essentially, it more or less outlines what factors happened to guarantee that such and such an event happen or what would have transpired instead that would have stopped it from happening, a bit like in Bill and Ted when Rufus has to go back. The slight difference is that rather than Rufus being told that Ted is about to fail instead he is instead informed that his job is to go back to the event and make sure that this doesn't happen. So, in a way, they send a faction to a certain major event in time to just make sure nothing happens that would prevent events from actual occurring.

This saves the trouble from the holes that would develop instead by setting up the premise that they have the technology to detect when something has gone wrong because that posits the question - what timeline are they currently on? How exactly do they know their timeline is suddenly not accurate? They cannot be explained to exist on a different dimension because they would still not be free of the influence. Let's say they get all their information from dimension Y, which is their real timeline. In order to prevent hiccups from developing in the database they move their base of operations to dimension X. However, this can't work because their information was taken from dimension Y. So if something happened in dimension Y, like say the titanic suddenly never sank, then that is hat would be saved in dimension X as this is where they're getting their information. Which is something that really bugged me in Back to the Future. Great movie and I still love to death, but when you stop to think about it...well, that's when you realize you really shouldn't.

So the idea that their job is to just make sure events happen, that they monitor time rather than go back in time to correct it, sounds like hiccups are less likely to occur. The way I see this as the best option is because the government's job is to then assign people to periods in the past as opposed to somehow knowing when events have suddenly gone off. In order to make sure that they don't send a large number of people to one particular event they keep record of it, essentially like when people check in at work at their shifts. They then live in that moment of time, doing very little to interfere and be part of the timeline and only interfere when it is necessary. In addition to this, the organization would also have resources that would let occasionally them essentially know if a specific event was going to be targeted by an opposing group. Does the theory hold? Would it make sense?

There is always the idea of a Deus Ex Machina, a le the time lords from Dr Who that are essentially free from the effects of time-travel. I did suggest this to her when she was first working on it but we both felt that it was rather overdone and just way too uncanny. I really liked her idea of wanting to do something that sounded mildly realistic [sounds a little funny to say in a discussion about time travel, but you know what we mean].

What are your thoughts? What are your arguments?

There is no "time force."  Time is a dimension, like x or y.  Your first thought is basically what I was saying, that they need a chain of time command to pass known history up the ladder and make sure it happens the way they remember it.  

I'm not sure what "database" you refer to.  The problem with detecting "when" something has gone wrong is that you'd be detecting time travel itself happening in the present, because "when" would be way back in the past.

I say stick to your idea of passing information on what "should have happened" forward, and have that information...I dunno, wave your magic sci-fi hands and say that you can transport it back in time as pure information in crystal structures in minerals or something.  Then maybe that's impervious to the meddling of time travelers, but some place obvious that people would look for it back in the past.  Limit time travel to a few decades or so in the story so that you can't go back ridiculous amounts of time and technology shifts before that...basically, not before the people who found the "organization" you speak of to start discovering that time travel is possible and that they have information about the future.  Foremost among that information being that people are trying to muck about in the past and might make everything way worse if they lose knowledge of the future.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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