Time Travel In Stargate SG-1
Introduction
As it has been noted many times, time travel is a subject best avoided in speculative fiction, due to its inherent problems with causality — especially when you have to take into account events which you, as a writer, have not invented yet but which can retroactively become continuity busters. Even when the writers do bother to create a reasonable model of time travel, the temptation to divert from it for the sake of spectacle is just too high. Doctor Who is probably the worst offender here; not even trying to explain how time travel works, it goes for the “timey-wimey ball” explanation and chooses whatever fits the story for a particular episode.
Stargate SG-1 is less zany in this respect, but it also hasn’t bothered to create a consistent model and stick to it. However, it is clear that within this model, the past can be changed — as seen in “2010”, “Moebius” and “Unending”. Having nothing else to work with, I will take M. Joseph Young’s model of mutable timelines and see how wellSG-1fits that scheme.
http://www.mjyoung.net/time/From now on, I will assume that the readers are familiar with the terms “N-Jump”, “infinity loop” and “sawtooth snap”.
“1969”
This is the first time travel episode in the series. In it, the SG-1 team is given a note by General Hammond, which they use to earn the trust of Hammond’s younger self and predict a solar flare that allows them to use the Stargate to return to the future.
Here we run into a problem. In the model of time travel exemplified, for instance, by the film12 Monkeys, history is immutable — and thus, the events “have always happened” as depicted. As Justin B. Rye puts it in his article “SF Chronophysics”, “attempts to ad lib always turn out to have been scripted all along.” The episode “1969” can fit into this theory and make sense, forming a closed loop: the members of SG-1 use the note in their encounter with Hammond’s younger self, and the memory of this event inspires Hammond to write a note to self 30 years later. However, this “stable time loop” isnot how time travel works inStargate SG-1, as seen in subsequent episodes.
Therefore, there must have necessarily been anoriginal timeline in which SG-1 never traveled to 1969and thus, General Hammond has never met time travelers from the future as a Lieutenant. Virtually nothing remains of this timeline as of the events depicted in the episode, so we can only rely on our logic to reconstruct it.
First Change: The Trip to 1969
For all we know, there may not even be a Stargate Command in this timeline — the members of what is SG-1 in the final timeline may have arrived to the past by other means (although SG-1 is unlikely to have affected the past too much for this timeline to be too divergent from the final one). This is not relevant. Somehow, this original SG-1 ends up in 1969; what’s important is that they don’t have Hammond’s note.
By traveling to 1969, the teamcreates a second timeline, different by the mere fact of their presence. When they meet Hammond, the conversation no doubt proceeds differently than shown in the episode; what’s important is thatHammond now has the memory of meeting them. The fate of the original SG-1 in this timeline is not as important as it might seem. Remember, when time reaches 1999 again, with a different SG-1 growing up, it will be again thrown back to 1969 — not advancing a single second past this new SG-1’s trip until the temporal anomaly is resolved.
Now we get to the events of the episode “1969” as depicted on screen. The timeline has already been altered once, and now SG-1 is going to alter it once again — because now they departs with Hammond’s note in their possession. Here’s a question:what is Hammond hoping to achieve by giving the second SG-1 the note? The fact that he even bothers, instead of letting everything occur as it did the last time, shows us that he did meet SG-1 in this timeline, but something went wrong — something he is hoping to correct.
Perhaps he was not convinced by their assurances that they were from the future, and let them be imprisoned. Or perhaps hewasconvinced — but without information about solar flares, SG-1 had no way to get back to the future. What follows is my reconstruction, which is not necessarily canon: Carter tells the younger Hammond that time travel works by traveling through a Stargate during a solar flare. Hammond doesn’t know at the time what to do with the information, but when the time comes, he recognizes the people under his command as the time travelers he met in 1969, and after realizing which trip through the Stargate is going to result in SG-1 ending up in the past, he digs information about the nearest solar flares that could help SG-1, and sends it along with a note to himself to help them. By doing so, he hopes to that SG-1 will now evade the grim fate that he unknowingly subjected them to “the first time around”.
Second Change: The Note
Now possessing Hammond’s note,the second SG-1 travels to 1969. Note that the original timeline has now been erased and overwritten by the second one; the events leading to the original SG-1’s departure have never happened, and therefore, when the second SG-1 (which replaced the first in this timeline) travels back in time,creating a third timeline, they will find it a clean slate — there is no leftover first SG-1 from the original trip.
If it seems a non-trivial point to you, imagine that you travel to the past, don’t upset the timeline significantly enough to stop your trip from taking place (which you could do, for example, by killing your younger self), and witness the event. The new timeline has created a new you, who is nevertheless very similar because the timeline is almost similar, except for the presence of the older you — and so the trip that originally brought you to the past will be repeated in this new timeline. It would be inconceivable if two almost identical copies of you appeared at the same point of time and space — it would mean that each “iteration” of time travel would change the timeline further, with the number of copies increasing with each subsequent trip. No, the time-traveling you from the second timeline will replace the time-traveling you from the erased first, and time will continue to develop as normal. And on the contrary, if you do make a conscious effort to prevent this trip by killing your younger self, the result will be that the subsequent timeline will not have you traveling to the past at all — throwing time into an infinity loop alternating between timelines in which your trip into the past does and does not occur.
In the third timeline, SG-1’s escapades in 1969 proceed as depicted on screen in the episode. They meet the young Hammond, show him the note (giving him the idea about solar flares in the process), and reach the Stargate with the intent to return to 1999. They only get there via a roundtrip, which deserves a special mention — but for the time being,the first N-Jump resolves itself in a sawtooth snap, and history can now continue past 1999.
Third Change: To the Future and Back
Unfortunately for SG-1, they end up not in 1999 but in the future. Cassandra, who’s a little girl in the series, is now an elderly woman, and meets them in the gate room, which now looks very different (and the Stargate itself is apparently abandoned).
What’s important to realize is that time travel to the future does not, by itself, create temporal anomalies. The effect is no different than SG-1 going to a remote planet through the Stargate in 1969, cryogenically freezing themselves until that date, and then coming back to Earth.They simply missed all the years between 1969 and this date, and thus, history unfolded without SG-1’s presence.Which means that they arrived into a future in which none of the events of the series after “1969” happened as depicted.
What does it mean for Earth, the Goa’uld, and Cassandra? Remember that the Protected Planets Treaty (“Fair Game”) was only signed after SG-1 killed Hathor (“Out of Mind/Into the Fire”) and Seth, alerting the System Lords. Therefore, without SG-1’s reckless actions, the Goa’uld would possibly just leave Earth alone: Apophis, the archenemy of the Tau’ri, is now a non-entity, and the attention of the System Lords will soon be diverted to the clashes between Sokar and Heru-ur, and away from that insignificant little blue planet and its primitive people. Furthermore, let’s presume that after the loss of the SGC’s flagship team, the Stargate program is closed, ending all of Earth’s extraplanetary affairs. (Note that the Protected Planets Treaty negotiations must necessarily not occur: without SG-1 there to expose Nirrti and negotiate for more favorable conditions, they would result in permanent loss of both Stargates, effectively leaving SG-1 stranded in the future when they get there.)
It should also be noted that the events in the future also did not originally unfold as shown on screen. Cassandra mentions that Carter told her to wait for them. This can only happen if Carter already knows where SG-1 is going to end up, which is impossible when they get to the future “for the first time”? So what happens? Presumably, they are recognized by the current authority at Cheyenne Mountain as the USAF team that went missing decades ago, resulting in the closure of the Stargate program, At their request, the Stargate is brought out of storage and activated once more for this specific occasion — after Carter memorizes or writes down the date and time of their arrival.
Then, after Carter makes all the calculations (correct this time — note that it’s irrelevant what happens to Cassandra in this SG-1less timeline, she may well be dead),SG-1 goes back in time to 1999, creating a new timeline — and another sawtooth snap in this far future.In this timeline, the events of the series occur largely as depicted — and at some point, Carter, now having the date of their arrival, tells Cassandra when to expect it. The events of the series can unroll as shown in the later seasons, now that SG-1 is present in this time period, and when the time of SG-1’s arrival comes, Cassandra is there — and the arrival occurs as shown in the episode. Why would Carter request Cassandra to meet them? Perhaps she saw something in the future that she wanted her “replacement self” not to know, hence all the precautions to prevent SG-1 from learning about the future too much. No matter what the answer is,the temporal anomalies in the episode “1969” are successfully resolved.
“2010”
This is noticeably easier to analyze than “1969”, as there’s only one temporal anomaly; however, there is still one caveat deserving a mention.
The plot is simple: in the year 2010, after discovering that the Aschen have basically doomed the Tau’ri to eventual extinction, the former SG-1 conspires to implement a truly insane world-saving idea: to send a note to the past to prevent contact with the Aschen from ever being made. Insane because having a dying out sterile species is one thing, and inadvertently destroying time is another. Generally speaking, successfully changing the past in a desired way erases your reason for doing so, and if you don’t explicitly take extra care to preserve the timeline, you will end up with an infinity loop.
Nevertheless, they carry on with the plan. Back in the year 2000, the SGC receives the note, and Hammond declares the Aschen homeworld off limits. As seen in “2001”, in this new timeline which overwrote the one seen in “2010”, an alliance with the Aschen is never made — and thus, there is no need for SG-1 to send the note back in time.
Here our story halts — for now. As theStargatefranchise progresses in real time, we are still two years away from the point from which the note was sent.If the note is not sent back in time in this timeline, the events will proceed like in the original Aschen timeline — and everything is lost, even time itself. However, so far there seems to be no need to worry about it. Provided Carter realizes that the note came from an averted future, and the danger that this setup poses, she can always calculate how to send it to get it to the SGC at that exact time, get O’Neill to create a replica of the note, and send it. The replica doesn’t even need to be precise, or to be sent at exactly the same time — they are creating a sawtooth snap with the goal of terminating it with an N-Jump. Eventually, history will stabilize — one of the timelines will exactly repeat the preceding one — and thus, time will be able to continue past 2010. The possible crisis is averted.