It is not just in the comics that time a major element in many stories. Nor is it only in the recent few years that the draw of time travel has interested people of imagination. One can suppose that the first popular story about time travel was by H. G. Wells, in his novel The Time Machine. More recent adventures in to the timestream can be found in the classic, as well as the New Generation Star Trek shows. Many people will remember Harlan Ellison's Star Trek episode where Bones goes back in time and changes history. Regardless of the medium, all stories about time travel have the same basic features and general requirements. While the rest of this essay specifically addresses our beloved medium, it applies to every means by which tales are told.

Stories about time travel can easily put the writers in a corner. Nothing against comic book writers, but they are only comic book writers. I don't know of any with an in-depth background in quantum physics (except maybe Christopher Priest), or whatever science it is that studies time and relativity. There are a lot of loose ends involved with moving back and forth along the timeline, and because of a lack, or low degree of hard-core scientific knowledge, it could be very easy for the writer to become muddled and write him/herself into a corner. Of course this may not be all be all bad. With knowledge comes preconceptions and paradigms. Comic book writers may not have the scientific background to lock down their stories in accepted scientific theory, but their imagination may cover and explain away whatever holes or inconsistencies that may occur.

Whenever a writer decides to muck about the past he/she has to make the determination as to how you can tell the story without going beyond the realm of suspension of disbelief by the reader (the first essential element of all comic book readers). The writer must come up with a plausible means by which everything remains the same in the current continuity despite the actions that took place in the one to five issues set in the past. Normally, this is achieved through one of the three methods.

First is that all the actions that took place somehow didn't make any changes to the current continuity. Despite the fact that a superhero/villain confrontation took place, it was all within a small window of probability that allowed subsequent events to occur that wouldn't change the current continuity.

Second is that there is an all powerful entity overseeing the timeline, and whenever there is a disruption in the timeline this entity makes everything right. At least as right enough to get us to our current continuity. (Astro City did something like this, but with a realistic tone. Not everything was put back together exactly as it was meant. This left some loose ends and make for a more realistic story.)

Third could be that the actions in the past change the current continuity, but since we are already in the current continuity, the changes that had been made merely spawned another reality that headed out on its own timeline, and never affected the current continuity.

Of course there is the a fourth possibility, and that is where major changes do occur in the current continuity. We can call this a Crisis, or Zero alternative. If done poorly, the story line will seem contrived and not spoken about without a lot of eye-rolling and exasperation. In other words, it can be a real embarrassment to the comic community. However, if done properly it can fix a lot of continuity problems. Of course the question arises, "If it can be done once, can it be done on a regular basis?" And if the answer to this question is yes, then the entire foundation upon which the universe is setting could crumble without much trouble.

If the DC organization decided that they had sufficient cause to create another "Zero Hour" or "Crisis" fixer-upper story lines, then the current Hal Jordan story line could be the means by which to pull it off. When Hal visits his future, he learns a lot about what has happened between then (the time when he was just beginning to be the Green Lantern) and now. Writers could easily send Hal back into the past where he could make some specific changes to history. Barry, Ollie, Kyle and Barbara could have some very different lives. Here we have a respected and long-standing member of the DC universe who could make some significant and acceptable changes. If this were to happen, then one of the three (four), aforementioned things would happen to the current continuity. One would hope that the power which allowed this significant event to occur would somehow be closed off for future changes (to preclude the crumbling foundation theory from occurring). Max Mercury, the Zen master of speed, has been bouncing forward in time for quite some time. His travels are well within the suspension of disbelief since it is very difficult for him make the jump, and when he goes forward, he isn't able to go back. This may be the philosophy for making "permanent" changes to the universe by traveling into the past. Make it hard, and make it hurt.

What about the future? When not placed in the present, it seems that most of the stories are future rather than the past. We glimpse the distant future, but don't know the years between. This isn't for lack of future characters visiting their past. We just don't receive too much definite future information. Characters from the future visiting this era either find that the past as they knew it changed, so the future as they know it has or might change. The readers of The Flash are all very aware of the fact that Iris knows much more than she is telling.

This all brings us back to the question of, "How super do we want our superheroes?" Time travel is terrific but when characters can transcend time (the way Wally West has been recently doing), they are pretty much able to write their own history and future. What does this mean? It means that writers need to be careful when they move along the timeline, or else they will tear the fabric of our comic universe until it is a rickety house of cards in a wind tunnel, or shaky as a fiddler on a roof!