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Handling time travel from faster-than-light travel

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#1 AaronWizardstar   Members   


Posted 13 November 2013 - 07:06 PM

When pondering my pipe dream space opera game, I looked up some things on that infamous sci-fi plot device known as faster-than-light travel. Today I learned that not only are there physical limits on actually getting past the speed of light, if you could magically outrun light you get time travel for free.
This presents several challenges to designing the setting and plot of my (admittedly theoretical) game. I'd have to figure out how an interstellar society with time travel would work. For the actual game, which would basically be an RPG/strategy hybrid akin to Heroes of Might and Magic, I'd be obliged to simulate the time travelling somehow; the time travel couldn't just be a plot device like in Chrono Trigger. Finally, there's the likelihood that the game's original sweeping tale of Jedi robots punching zombie dragons would get overshadowed by all the time travel stuff.
I'll note that the idea I had for my game is a bit unique in that it would actually be a fantasy set in space, with Harry Potter and Doctor Strange stye wizards zipping around the stars. But the ability to magically control reference frames seems a bit much.

Edited by AaronWizardstar, 13 November 2013 - 07:09 PM.

#2 Tom Sloper   Moderators   


Posted 13 November 2013 - 10:01 PM

The way time travel would really work is that you'd travel into the future, and cannot get back to your original time.
-- Tom Sloper
Sloperama Productions
Making games fun and getting them done.

Please do not PM me. My email address is easy to find, but note that I do not give private advice.

#3 Hodgman   Moderators   


Posted 13 November 2013 - 10:08 PM

Don't you only need to consider the actual implications of FTL travel if you're making a hard-sci-fi game? If it's fantasy or soft sci-fi, you can bend the rules however you like, instead of listening to physicists... You can just say that we invented point-to-point portals, with no effect on time -- especially as FTL travel is still very hypothetical; it's been theorized in several ways but of course never demonstrated.


Anyway, even if you do listen to physicists, there's many different hypothesis on how FTL travel could be constructed, some allow for backwards travel in time, others only forward travel, others create branches in a multi-verse (travel into a parallel world)... Even if making hard sci-fi, you can pick whichever model best fits your story.

Many of the current theories of how it could be done also require more energy that human civilization is likely to ever acquire, so if we do manage to do it, it will likely be via some other, currently unknown method.


BTW you simply can't outrun light, as in, you can't take a lump of ordinary matter and accelerate it to above light speed. Not even with an infinite amount of energy. It's a nonsensical proposal, like trying to fit 2L of water in a 1L bottle at regular pressure levels.

FTL would require cheating the system, by not actually moving the object at all, and instead deforming spacetime around the object, etc...

Edited by Hodgman, 13 November 2013 - 10:11 PM.

#4 rem3017   Members   


Posted 15 November 2013 - 03:28 AM

I wouldn't exactly call FTL travel a sci-fi plot device, especially in space based video games.  it's more of an in general simple explanation for traveling long distances really quickly.  In fact, most games tend to just gloss over the exact science of space travel, using travel animatics simply as a make shift loading screen.


If you're not going to make the passage of time (real time, not story time) an integral game mechanic, i'd avoid trying to go into crazy depth with the methods in which your character travel.  Hell It may even be worth coming up with your own outlandish technology.

#5 samoth   Members   


Posted 15 November 2013 - 06:01 AM

I would completely ignore the effects of faster-than-light travel because it is not fun (to most people, anyway) and doesn't add any real value to the game (If you want time travel, you can add time travel devices, and it doesn't even matter how they work! Anti-buzzon inverters if you want, or gremlins, or simply "unknown alien tech".) but being too realistic adds considerable trouble and spoils fun. I would also make communication (radio, video conference or "holonet" or whatever it is) faster than faster-than-light. Who gives a crap, it has to work or people are unhappy.

Also, firing your lasers on a FTL ship should cause the laser beams to travel faster than light, and faster than your ship. But generally, they should be slow enough so a human can see them (how do you see them anyway?) and do an evasion manueuver.


In Star Trek, they don't waste much of a thought on the speed of light (though in Voyager, they do, somewhat half-assed, and in one episode of DS9 as well, and of course there is the famous "Picard Manueuver"), nor in Star Wars. You can call someone at the other side of the galaxy no problem, and have a nice conversation without any lag. After ending the conversation, you can even see the other starship which is in a different solar system from the exterior when there is no camera to record this picture at all! Great stuff. It's not realistic, but it also doesn't suck.

Imagine Picard is calling Starfleet to tell them the Borg are coming. Too bad it takes 8 weeks before the other end to turn on the monitor and says "Hello? What's up?", and another 8 weeks before the "Hello" arrives. And he still hasn't told them a word. This sucks. How do you fit this into a 40 minute episode?


It is "somewhat OK" if it adds something to the story, such as in this DS9 episode where that woman captain which Sisko gets involved with wants to dearly see the recording of this baseball game her brother played, and the signal transmission takes 3-4 weeks since it's as far away from Earth as DS9, but in the opposite direction, blah blah. It is a nice plot device because it gives the couple an occasion to get together on something special that they both like. Which is, of course, what matters for the story. Except Sisko can talk to the guys on Earth (including his father at home, so it is not some super secret military special technology) in realtime without any delay at all, so... bleh. So much for consistency.


Also, story and "game fun" apart, what we "know", or what physicists say isn't necessarily true. If you're being realistic, they're just telling you what they think, not what is truly the case (though incidentially those might be the same thing). It is true that so far no evidence has been found that would dismiss the idea of time dilation, but there is no verifiable hard evidence for it either. Yes, one or the other petty thing has been measured here and there, and it doesn't contradict, but truth is we know absolutely nothing about travelling anywhere close to relativistic speeds, let alone faster than light. Even if all assumptions for "close to" are known to be demonstrably true one day, this still doeesn't extrapolate to "faster than". Until we do travel faster than light, it's all just talk, and talk is cheap.


Many of the models and arguments (such as e.g. about causality) aren't necessarily binding. For example, who told you that there is any such thing as causality in the universe or that it has to be "fixed"? Maybe the universe is perfectly happy with things that you deem paradox or impossible.


Measurements are not necessarily binding either. Whatever you think you measure might be an entirely different effect. And, what's true for a sub-atomic particle (or for light) might not at all be true for your spacecraft and your body within.


Let's say you an atomic clock in a shuttle and have it go around the planet a few times and compare it to another one. Wow, they're different. What does it tell you? It tells you that you cannot dismiss the time dilation theory, but other than that it tells you exactly nothing. You have no idea whether the atomic clock did fewer "blips" because time was dilated, or maybe because the acceleration then the shuttle lifts off causes the atoms to "bang together" in a particular way. Or maybe cosmic radiation has an influence, or something else. Gremlins!

But even assuming that what you've measured is absolutely conclusive without any possible doubt, it only tells you about an effect that happens at pathetically slow speeds. The fastest (unmanned) spacecraft in history has reached 0.02% of the speed of light. You cannot possibly know if the same effects that happen at 0.02% are still happening at 50% or 90% or 99% (or at 150%!). Maybe matter transforms into "ether" at 99.99% the speed of light. How could you know for sure that this isn't the case?

#6 Bregma   Members   


Posted 15 November 2013 - 06:31 AM

Well, the Lorentz equations show us that you can never accelerate to the speed of light.  They also show us you can never decelerate to the speed of light.  They say absolutely nothing about travelling faster than light, except that (1) if you're travelling slower than the speed of light you can never travel faster than the speed of light, (2) if you;re travelling faster than the speed of light you can never travel slower than the speed of light, and (d) if you're travelling faster than the speed of light, the sign on the time component is negative.  In other words, things that (theoretically) travel faster than light also travel backwards in time.


The result of that in a hard-science universe is that people can't travel faster than light, but conceivably information can.  In fact, you could receive information from the future if you can somehow harness the tachyons that are travelling backwards in time.  This is the basis of the ansible, a communication device that appears in some fictional universes that allows virtually instantaneous communication across galactic distances where physical transport can take a lifetime at sublight speeds.


Consider the plot-device aspects of time-reversed communication.  Just a suggestion.

Stephen M. Webb
Professional Free Software Developer

#7 Acharis   Members   


Posted 17 November 2013 - 12:24 PM

Ignore it. Players won't really mind nor care... There is "suspension of disbelief" that players are supposed to provide :)



Besides, you are not fully correct. It's not possible to go beyond faster than light (except cheating like wormholes, but that's not about the speed but distance), not within Einstein's model of the universe. Going above the speed of light would break more things that free time travel...


To be more precise, space and time are inside the same equation. When you increase space (like speed) then you *have to* decrease time. So space + time = always 1, therefore if space (speed) would ever go above 1 this whole equaliton would go into negative numbers... And that would make the whole Einstein model universe made kaboom :D



Working on an Emperor focused, no micromanagement, asymmetric, 4X, space empire builder:

Stellar Monarch (4X, turn based): GDN forum topic - Twitter - Facebook - YouTube

#8 SilverRoan   Members   


Posted 20 November 2013 - 10:13 AM

Time travel to the future or not is a paradox / complex matter. I suggest you don't bother yourself with it, as long as it makes some sense and is presented nicely to the player.


Don't try and solve the logic behind the speed of light. Especially if you don't have at least Ph.D

#9 CatmanFS   Members   


Posted 26 November 2013 - 02:51 PM

While we convince ourselves that these limitations exsist, there is a certain uncertainty in the universe that tends to make anything possible. The writing for your game should be able to convince the players of this, give them a reasonable explanation, but leave things open ended and kind of mysterious. You're not teaching a quantum physics class, so you have a bit of artistic liberty when it comes to these things. Offer secondary explanations that allow for whatever your game needs. You're not writing a history book, so put what you want in it so long as it maintains the user's sense of immersion and can manage to suspend disbelief. People want to be told that it's possible, whatever it is, so just find a way to make it so and make it seem believable to a certain extent.

#10 Norin   Members   


Posted 18 December 2013 - 11:32 PM

I faced similar questions for a storyline I made up awhile ago. Here is the way I proposed "plausible" solutions to the problems, which is essentially pushing the implausibility around:


1) There was a discovery of matter with negative mass. These negative mass bodies offset the mass of whatever is traveling through space/time and make the calculations much more reasonable. Positive matter weight in the ship is very important, so essentially the ships weight nothing.


2) Ion drives, made possible by shielded magnetic cores at almost 0 degrees Kelvin, allow these physical ships to travel near light speed. An additional field around the ship moves space/time past the ship in a doughnut, which makes the perceived travel time FTL.


3) Communication is instantaneous across any space/time gulf because the ships all have crystals that have been quantum entangled. "Whatever happened to one particle would thus immediately affect the other particle, wherever in the universe it may be. Einstein called this "Spooky action at a distance." Amir D. Aczel, Entanglement, The Greatest Mystery In Physics


In my world, one massive crystal was created by millions of lasers firing into Beta Barium Borate, and the entangled photons were siphoned off into smaller crystals, and those crystals were further entangled, until the entire crystal was one entangled unit.  It was then shattered and the shards embedded into each ship with a lazer matrix around it which converts light and sound into light and transmits it to the other crystals simultaneously.  Communication is thus a cacaphony of entangled information, and two-way conversations consist of selectively filtering signals.


4) Stable wormholes can only be created by other quantum entangled "endpoints" which have to be physically delivered.  When man and the silicates wanted to explore the stars, they sent scouting ships ahead whose goal was to get as far as they could in space time, then drop their endpoints. Since the endpoints were quantum entangled with earth, it *mumbled scientific explanation* and created stable wormholes.  Back on earth, the wormholes just started popping up with huge gates in space like airport terminals. But for the scouting ships, the creation of a wormhole represented its life's work, hundreds or even thousands of years worth of FTL travel.


I made a rough-cut trailer for it, and I'll provide you the link, even though I pretty much suck at video editing (hence the term 'rough cut'):


#11 powerneg   Members   


Posted 07 January 2014 - 04:04 PM

This presents several challenges to designing the setting and plot of my (admittedly theoretical) game. I'd have to figure out how an interstellar society with time travel would work.

Heavy regulations.

It realy depends on how easy time travel would be, but i 'd expect that ID-chips would have an internal clock that can be checked just to make sure that people/authorities know it when dealing with someone from the future.(and all kinds of creative ways to get hack the system)

Maybe special forcefields that prevent someone from another time to enter the time-place of that forcefield.

Getting help from the future would be an option as well, when you need help you just decide to ask/find help in the future and sending it back.

#12 Azaral   Members   


Posted 13 January 2014 - 10:25 PM

Most FTL is accomplished by moving space, not matter. Space can move as fast as you like as far as we know. The universe expands at something like 3 times faster than the speed of light. That's how they do it in star trek. They move the space around the ship to move the ship instead of directly moving the ship. Since the matter isn't moving at FTL speeds, infact it's not actually moving at all, it's time remains constant from when it left.

It's like putting something in a box to move it. The thing itself isn't moving, but the space containing the thing is moving, so it moves the thing along with it.

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