This will be the first of several posts that will consider time travel as presented by Harlan Ellison. I’d like to start with one of his most popular works, the “City on the Edge of Forever” episode of Star Trek. The basic plot is that the Enterprise detects a violent time and space disturbance on a remote planet. During the disturbance,a man is injured (Sulu)and the doctor (McCoy) goes to treat him. There is an accident that leads McCoy to inject himself with a medication that renders him psychotic. In his deluded state, McCoy beams himself down to the planet. A landing party goes down to look for McCoy, and they find the source of the original disturbance, a portal back in time (for some reason, this time portal is also a space portal back to Earth, but never mind that). McCoy, still deranged, runs through the portal. Fortunately, Spock and Kirk are able to get the Guardian (the intelligence controlling the portal) to show them the passage of time that McCoy was looking at when he ran through, and they go through the portal to depression era New York. Fortunately for Kirk, there’s just enough time for him to…ehem…”fall in love” (hey, this time it seemed like the real deal) with Edith Keeler, the woman running a boarding house that they come across whilst escaping the police after a petty theft. Spock is able to fashion a crude circuit that can read the information recorded by his tricorder while the portal was showing the passage of time. Among these details, he sees evidence of two timelines, one showing that Edith Keeler dies in a car accident in just a matter of days, and in the other timeline she leads a pacifist movement just as World War Two is breaking out,and this leads to the dominance of the Nazis across the world. Spock hypothesizes that it is the accident with McCoy that has disturbed the original time line and created this second time line. He’s convinced that Keeler must die, and in the end, he and Kirk prevent McCoy from saving Keeler as she accidentally steps out in front of a moving vehicle. She then dies, restoring the original “safe” time line.

The are a number of problems with this as presented. First of all, there’s a bit of a debate among physicists whether or not its even possible to travel back in time. Sure, the equations of general relativity seem to indicate its possibility, and Kip Thorne of Caltech, and his collaborators have written extensively on the subject for the last 30 or so years. However, some physicists feel that since the solutions would on their face allow for backward time travel, and thus interference with the past that could lead to paradoxes (such as killing off your own ancestors,thus leading to you not existing, and thus not able to create your “time machine” and travel to the past, that the very intrusion of these paradoxes suggests that backward time travel is not possible (this is not the only instance in physics for which a mathematical solution is eliminated from consideration because its not logically applicable to the situation. Others feel that perhaps the backward time travel is indeed possible, but that through some as yet understood intervention, interference in the past is prohibited. In any case, the exact solutions of Thorne require some bizarre conditions such as “negative energy” and the manipulation of wormholes moving near to the speed of light. It would be an understatement to say that we do not know of a way to create these conditions as yet. Perhaps we will come across this sort of “time machine” in deep space.

Then there’s the issue of multiple timelines. Although there are some formulations of quantum mechanics, such as the “many worlds hypothesis,”
that allow for multiple time lines, there would be no way to travel between these timelines or even get information from one time line or “world” from another (as Spock did). And even then it seems implausible that the folks moving from timeline to timeline would keep the knowledge of their experiences in the other timeline. That is, it would seem that everyone, once going back through the portal would forget that anything even happened jeopardizing the world (because, in essence, it didn’t!)

Still, its a …forgive the pun…timeless story by Ellison, with only some minor violations of time travel theory, so long as you accept that somehow the “guardian” is really accessing a wormhole through the ring portal. I think I can do that. Can you?

If this interests you feel free to read more in paperback or electronic versions: The Physics and Astronomy of Science Fiction, by Steven D. Bloom,
available from McFarland Publishing or your favorite electronic bookseller.