More Time Travel, Less Silliness Part 1

People have been writing about men traveling back in time for so long that even Mark Twain wrote a book using it as a plot device. However, while there are a lot of things that make it interesting to read, especially in the hands of someone who loves it, there are also lots of ways to mess it up. Generally, the person who messes it up usually doesn't bother with the "science" part of science fiction; they actually hate science and/or just want to deal with philosophical aspects using the tropes as metaphors. However, by looking at time travel more analytically, more ways of exploring things may be uncovered.

Time Travel is By Necessity Space Travel

Something to consider: Galaxies are moving at near-light speed. The stars within them are lapping the galaxies. Each star with planets has those planets moving around it in orbits. Planets rotate and continents drift. Even the plants and animals on those planets move over time.

This means that nothing is in the same spot as it was even seconds ago. When you start looking at things from the cosmic scale, this means that things are light years from where they began life in a relatively short time.

From the perspective of time travelers, it means that if you travel back in time even a few minutes without traveling in space, you'd most likely end up in space nowhere the location you were planning on being. The show "Red Dwarf" pointed this out numerous times during its run. Even "Doctor Who" has mentioned the problem multiple times; this is why his vehicle is called the TARDIS, short for "Time And Relative Dimensions ins Space," recognizing that the physical dimensions need to be allowed for. "Strontium Dog" even has a grenade that throws everything in its area effect back 24 hours, effectively putting it in deep space.

While you can hand-wave this by saying that a time traveler follows the planet he's on back in time or even ignores it, it is something worth keeping in mind when you're developing your own version of time travel.

The Conservation of Time

Sorry, Whovians, but Doctor Who didn't create the idea of hard points in time. When people started debating the possibility of time travel, they also started debating how inevitable certain events were and whether or not certain events would be sacrosanct or just part of the general time line. Keeping it simple, there are three basic theories about this conservation of time: Just pick one and stick to it.

• Chronal Apathy: If something happens, it happens. If it doesn't, it doesn't. This means that if the time travelers stop something from happening, make something happen, or make any sorts of changes, then they stick. This means that the timeline will change forward from that point. While the time travelers are likely to be immune to the situation and become living paradoxes (they came from a time that no longer exists), they're going to find things radically changed when/if they return. Of course, if they find a way back to the origin point then they can change things back to normal, possibly with changes. 
• Story Effect: This allows you to make changes in the timeline and they stick, assuming things aren't changed back. It also allows you to make small long-term changes.
• Ripples of Time: Some events are too big to not happen. This means that if a Big Event is stopped from happening, it's just delayed; it, or something similar, will happen in the future and it's just a matter of time. This can lead to groups being created to put off the event as long as possible as well as groups who want the event to happen. This can also lead to all sorts of prophecies happening warning of the event and possibly giving a clue how to stop it, or at least delay it.

[This applies to bad events as well as good ones; not all time travelers travel with good intentions, after all. This could lead to different groups competing to make sure certain events happen or don't and the conflict could lead to some interesting side-effects such as conflicting prophecies, evidence of what happens either way, people from different timelines popping up, and even the universe being threatened due to all of the time travel.]

Story Effect: If you like prophecies and things resetting, this is for you. This is great if you're making a point about how the status quo keeps returning or how some things are inevitable.

Hard Points: Some events need to happen; if they don't, even worse things could happen. This can either be events on the timeline will change to be more difficult going forward or that something cataclysmic will happen. Some time travelers can recognize them while others will be warned about them by their artificial intelligence or leadership.

The Paradox Problem

When you start looking at the timeline as less of a line, you begin realizing that sometimes the cause comes after the effect. There are three issues that need to be discussed here.

Multiple Bodies, One Time: In some time travel stories, it is disastrous if an entity from two different times contact each other: The same matter can't occupy the same space, but the matter being from two different times allows an exception to that. Thus, if Present You meets Future You and you shake hands, you should explode, right?

No. From a physics perspective, the two bodies are their own entities and so can interact just as any other two objects could. They could fight, shake hands, even wrestle with no ill effects; they are, for all intents and purposes, two different entities and so don't need to worry about the two exploding on contact. Doing so usually pulls people out of the story, especially when you keep using this to blow things up on a regular basis (yes, "Twelve Monkeys" series, we're looking at you!).

The Grandfather Paradox: Time will not protect your progenitors, nor will you fade out of existence. If one of your progenitors dies before committing to events that led to your creation, you're either a living paradox as you come from a future that no longer exists, or your progenitors were not who you thought they were (tip of the hat to "Futurama," where Fry became his own grandpa while the person he thought was his grandfather died).

Living Paradoxes: You're going to need to figure out what you want to do with living paradoxes (people who were created in one timeline but were in a different time when their timeline was rewritten so that they were eliminated from their original timeline). The simple version is to let them live as is but face chaos when they return to their original time (no one knows who they are, they don't have any of their paperwork, and they're now foreigners in their own time).

The "I'm a freaking masochist" version is to eliminate the person when their timeline is eliminated. The problem with this is that every trace of the person from the point of change forward needs to change; this means that if the person lost the ability to time travel then their entire presence has been eliminated. This means that you now need to figure out what this means and eliminate/restore everything that the person touched. Given the possibility for continuity errors, really, really debate this version.

Different Times, Different Prejudices

Some black writers seem to think every period of time had the same mentality as the Antebellum South (being white is considered "good", being black is considered "bad"). The reality is more…complicated. Race is a funny issue when it comes to history: While some groups based their prejudices on skin color, others stratified their societies based on skin color, and still other societies had prejudices that had nothing to do with skin color but other considerations like native/foreign, social status, or even the perceived value to society.

Put another way, there are plenty of societies where blacks were in charge and whites were second-class humans, those where your place in society improved with the darkness of your skin, and still others where being a soldier was more important than your skin color. There were also groups that had no idea what to do about black people; the Japanese knew what to do with its Ainu tribes and white men were the enemy, but black people just weren't covered.

But blacks are a relatively known quantity. Now, consider how a First Nations woman would be treated by medieval Arabians. Or Samoans by Romans. Keep in mind that we also only have the most general idea of how one group would treat another, based on writers applying their own biases and prejudices which may or may not be similar to the groups they came from, and that not every group had an oral history or even recorded its dealings with other groups.

But let's complicate this one more level: We all know that prejudice has a political aspect. This means that a black nobleman would be treated differently than a Samoan commoner, depending on the group they've encountered: Nobles would respect the nobleman as his wealth and power are something they understand and he would be something different while they would detest the Samoan as they would any commoner. Conversely, the commoners would respect the Samoan while rolling their eyes at yet another nobleman/

This gives you a certain freedom when it comes to dealing with prejudice. You can thus either ignore the issue of race, apply rather strictly, or even just work at it randomly (the person could either be god or demon, or be forced into a particular role based on the skin color, eyebrows, or even hairstyle of the time traveler). This makes it a neat little tool should you decide to play with it.

Of course, keep in mind that you're showing up from out of nowhere in clothes that are too new or just plain exotic, likely with hairstyles no one has ever seen, and that no one has ever heard of you; worse, you're likely to have nothing to trade so you're going to have to figure out food as soon as possible. You're also likely to not know the local laws. That's a level of prejudice that's going to make anyone's life interesting for a while.

So these are some thoughts on time travel. Hopefully, there is something here to help your current stories or inspire others. Time travel can lead to all sorts of weirdness so you need to keep track of the changes; if you play too fast and loose with your timelines, it can throw readers out of the story.