Time travel has been a staple of Science Fiction since (and maybe before) H.G. Wells’ “The Time Machine”. There are many different variations, and Lost is exploring a few of them. Here is a primer for those who have trouble keeping straight the possibilities…

There are three main theories about time travel.

One is a Straight Path or flow, there are no branches or alternatives. Events happen in a certain order and there is no way to change it.

Another is the Wide Pipe theory – things happen in a certain order, even though time can be manipulated in subtle ways, larger events will always happen as expected.

The Time Tree – time is continuously branching and creating alternate timelines. These timelines can exist simultaneously and can be jumped from one branch to another, up and down the tree. Changing events simply creates another branch. There are infinite timelines branches from every little event that happens in time. A butterfly that is killed by a time traveler in prehistoric times will drastically change the rest of history. This is known as the “butterfly effect” and was featured as a plot device by Ray Bradbury in his short story, “A Sound of Thunder”.

Now to confuse the reader even more is the concept of personal timeline; a time traveler will usually be conscious of experiencing the difference in time as he jumps. If a traveler goes back in time 20 years into the past and stays there for 2 years, then returns to the future at the same moment he left, he would physically be 2 years older, since his personal timeline had not been altered.

Standard Time Travel
A person simply goes back (or forward) in time, and then comes back to his present time without any repercussions. Time is represented as a linear path, and the traveler is able to jump around. Simple, right?

Time Twins
Time twins is when a traveler goes back in time and visits his past self. In a straight path timeline, both versions will remember meeting each other. The past self will know that one day he will travel back in time to meet himself. Some variations of this scenario includes a stipulation that time twins cannot come in physical contact with one another or else risk in both disintegrating on a molecular level (identical matter cannot exist on the same temporal plain).

In a Wide Pipe timeline, if a person travels back in time and tries to visit his past self, and has no recollection of this happening, he will be prevented in actually meeting himself. The very nature of the wide pipe will prevent this from happening.

In a time tree timeline, a person will be able to meet his past self, without the traveler having recollection of this. This is due to a new branch being created. Unfortunately this is not without it’s drawbacks. Since a new timeline branch has been created, the traveler is now in a different timeline, and will not be able to travel back to his own time unless he is able to jump between branches. Also, his past self is doesn’t have to travel in time from the future, and the two twins can exist and grow old on this new temporal timeline.

Consciousness Time Traveling
A traveler travels in time only through his mind – most cases back into the mind of his past self to relive certain points of his life. Sometimes it is the mind of another individual in the past.

In a straight path timeline, the traveler will only be able to experience his past without being able to alter events – most likely traveling to a point in his past where he was unconscious for a period of time (allowing the traveler to take control of his past self’s body without effecting the past self’s consciousness).

In a wide pipe timeline, the traveler takes control of his past self’s body but is still restrained by the timeline events. He would be able to alter smaller events, but the ultimate outcome would still remain the same.

In a time tree timeline, a traveler can inhabit the body of his past self (or anybody else’s) and is free to alter time, since the timeline would branch anyway. Like in physical time travel in this scenario, the traveler would return to a different future, unless he is able to jump back to his original branch.

Fortune Telling
Bringing information back into the past is another example that marks the differences of these time travel theories.

If a traveler goes back and warns of, say, the 9/11 attacks. Two possible outcomes can occur. The first, under the straight path timeline theory is that no body would believe the traveler, or the natural order of events would prevent the traveler from achieving success, and the events would occur as they happened. A similar outcome would happen under the wide pipe theory – except that while a traveller can successfully warn of the impending attacks, the attacks (in some shape or form) would still occur.

In a time tree timeline, the traveler successfully prevents the attacks and a new timeline is created. This new timeline however, is not the same one the traveler left – and will not be able to return to it, since the traveler never had the desire to time travel from that timeline to change something that never happened.

Paradox: Kill The Parents/Self
A traveler travels back in time to kill his own parents (or ancestor). This isn’t a true paradox (in my opinion) since the only way it can occur is in a time tree timeline scenario. A traveler cannot achieve this situation in a straight path or wide pipe timeline, since it would not be possible, a branch would be created if that ever was to happen – no matter what.

A wide pipe timeline would simply prevent this type of event occurring.

Furthermore, if a traveler is able to kill one of his ancestors or alter a situation in which breaks his ancestral line – he would not disappear – like in “Back to the Future”, since a new timeline branch is created, in which his future self was never conceived. Even if he killed his past self – he would not disappear or blink out of existence. He has merely created a different timeline in which his past self was killed.

Also, on the notion of death – it is possible to die while back in time in any timeline theory – since death is on a personal timeline. If you time travel back to say, 1955, and someone kills you, your corpse will continue on and an earlier version of your self can come across it.

Paradox: Time Created Objects
In a straight path timeline, if your future self appears to you and gives you, say, a baseball, then later in life, you create a time machine and travel back in time to give your past self that same baseball, you’ve just created a time object. This is a true paradox, since that baseball only exists in the time loop – it has no origin or no end, other than existing in this loop.

On the contrary, an object that is brought back in time and left there, would not be considered a paradox, simply because that object has a natural origin and an eventual end.

Paradox: Father and Son
Another true paradox is the parent child paradox in which the child is his/her own parent. Again, this only works in a straight path timeline. A traveler goes back and time and conceives a child which is the traveler himself.

Other Types of Time Travel

Tangent Universe – As shown in “Donnie Darko”, time exists in a straight path but an abnormally breaks the timeline into a tangent universe, which is temporally unstable and will eventually collapse upon itself. The only way to correct it is to fix the abnormally and put the universe back on it’s original timeline.

Focused Isolation – As shown in “Somewhere in Time” in which Christopher Reeve travels back in time to find his true love by isolating himself in a hotel room and believing he is back in the early 1900′s. His physical body is transfered back in time since his mind believes he exists in the early 1900′s and willfully forgets about the future.

Unstuck in Time – As written in “Slaughterhouse Five”, a man is unstuck in time while kidnapped by aliens. He relives events in his life out of sequence, including his own life, but is unable to alter it. The book uses the device of four-dimensional space/time, in which time is able to exist at any point at the same time.

Third Person – As shown in “It’s a Wonderful Life” and written in “A Christmas Carol” in which the traveller experiences (or is shown) different past and future events from a perspective outside his self, but does not interact with these past and futures.

This entry was posted on Monday, February 9th, 2009 at 1:14 pm and is filed under Lost. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.