It was suggested in comments (at The Examiner) that with the video release of Terminator Salvation this column should not only examine its place in the Terminator timeline but summarize the previously published and rather complicated analysis of the other three films.  Indeed, although it has stood the test of time to some degree, Temporal Anomalies in Time Travel Movies unravels Terminator was the first such analysis to appear (under a slightly different title with a different URL) when the Temporal Anomalies site launched in 1997.  Its consideration of the first two films dealt with some serious complexities, and made predictions concerning what the franchise might be able to do with the story from there.  Further, the more recent addition of an analysis of Rise of the Machines put the entirety of the first two films in a new context not fully addressed, despite the fact that several of the predictions of the previous article had been confirmed.  Thus as the fourth film has come to video, it seems appropriate to examine the story so far, and to polish some of what has already been said.

The story begins with the third film.  It is here we learn who originally designed SkyNet.  In the second film it appeared that Cyberdyne created the massive computerized defense system as a hardware system; but it was also revealed that Cyberdyne did so based on studying the parts from the demolished T-800 left in their factory in the first film.  This in the first film would have been a predestination paradox, the effect in the past dependent upon the cause in the future; but in the second film it became a grandfather paradox, as the cause from the future destroyed its own basis in the past.  Thus the second film forces us to abandon fixed time theory as a plausible explanation.  Assuming that replacement theory is the best replacement, that the people involved really are changing their own past (not the past of a parallel or divergent dimension), we then resolve the uncaused cause by postulating an original cause that was displaced.  In this case it is not difficult to do this, because the third film gives it to us:  as predicted, someone else developed a different SkyNet at a later date.  That someone was the Autonomous Weapons Division of the Cyber Research Systems branch of the United States Air Force, under the direction of General Robert Brewster.

It is not impossible that there was some other original creator of SkyNet, and there might have been contributors to the project; but it seems most reasonable to assume that the Air Force was working on autonomous systems long before the early nineties, long before the Internet had become what it was, and that they had been consulting many private contractors for the latest in hardware and software.  It is also evident that in the eighties the notion of harnessing multiple computers in parallel was in its infancy.  Answers were seen in hardware in those days; it was not until this millennium that software solutions rose to prominence.  Thus it is not surprising that in 1984 they were looking at hardware solutions, but by 2004 they were looking at a software solution.  It is also not surprising that absent the parts from the future, no hardware solution was forthcoming.  Hardware becomes dated very quickly and cannot upgrade itself; intelligent software might be able to manage both its own upgrades and that of its hardware, given the right tools.

Thus we find that the Air Force is responsible for the original creation of a SkyNet that was an intelligent defense program released into the Internet that became sentient and proceeded to defend itself against humanity.

The story then doubles back on itself, because that program eventually decided that John Conner must die; yet without that decision, John Conner could never have been born.  Thus we must turn back the clock to 1984 and Sarah Conner's child.

The original SkyNet was a software program launched on the Internet in or about 2004, as seen in Terminator 3:  Rise of the Machines.  That program eventually decided to attack Sarah Conner, because her child was leading an effective resistance movement.  The problem is, the child whom Kyle Reese comes back to protect in the original film is his own son whom he fathered when he traveled to the past.  We have yet another predestination paradox, because no one will travel to the past to kill the child unless someone travels to the past to prevent the child from being killed.

Again the solution lies in identifying the original cause, and the original cause must be that Sarah Conner got pregnant.  She met someone else who became the father of the child whose name might be lost to us, who might even have been a daughter.  Then, after the Air Force launched SkyNet, the offspring of Sarah Conner became the rebel leader that prevented SkyNet from achieving its objectives.  SkyNet developed time travel and created terminators, and sent something back to kill Sarah Conner.

We hit a snag at this point.  If the Terminator succeeds in killing Sarah, then her child is never born; that means that before anyone in the future can do anything to stop it, the Conner child has never existed, and they have no knowledge that there ever was such a person.  Thus the Terminator must have failed.  There are two problems with this, however.  The first is, if the Terminator failed, then everyone knows it failed, that Sarah was never killed and that the Conner child was born as anticipated.  Thus there is no reason to send anyone to protect Sarah, because she managed to survive.  The second problem is, how could a T-800 not have found and killed Sarah Conner, given how powerful we see it to be in the films?

Success has another problem, though.  If the Terminator succeeds, then the Conner child is never born, and SkyNet has no reason to kill Sarah Conner.  If it fails to do so, though, it creates an infinity loop, a grandfather paradox in which the cause in the future is undone, destroying the effect in the past.  This, though, is less problematic:  if the Terminator succeeds, it can shut down, wait a few decades, and then report its mission and its information to SkyNet.  SkyNet would then know that the Conner child mattered; the rebellion still would not, and the Terminator would be sent back to do what the resistance could never understand.  The resistance then would not send anyone to protect someone of no consequence.

Since Kyle Reese is ultimately sent to protect Sarah Conner, we are forced to conclude that the Terminator was not successful (or the resistance would not know to send anyone), but also that there is a reason to protect her.  The best extrapolation, then, is that the Terminator killed Sarah Conner as programmed, but not until after the child was born.  It had no instructions concerning the child, because SkyNet was after the mother.

As to how she could have survived long enough to deliver her child (a child not yet conceived when the Terminator arrived), we must remember that the Terminator we see in the movie is a consequence of its own contribution to its own development.  The original machine was not destroyed at Cyberdyne, and was not as powerful.  Thus it is not until Kyle Reese is sent to the past that things start escalating in a complicated interlocking sawtooth snap:  Kyle leads the machine to Cyberdyne, where it is destroyed; the parts are salvaged to build a better machine; Kyle's information to Sarah improves and changes as the Terminator becomes more powerful.  The original father of Sarah Conner's child is lost to history, replaced by Kyle Reese and his son, John Conner.  Cyberdyne quickly has a hardware solution that replaces the original software system, and SkyNet goes online much sooner.  Eventually a plateau is reached where Cyberdyne cannot learn more from the parts than it has, and the history of the first movie stabilizes.

The second movie then complicates it.

The second Terminator movie assumes that time has passed in both the future and the past.  In the future, the resistance has managed to capture and reprogram at least one of the old T-800 machines that had been so formiddable, and SkyNet has developed a more sophisticated machine and apparently also improved time travel a bit (the T-1000 does not have to be encased in living flesh).  In the past, John Conner has become a rebellious teen and his mother Sarah is a patient in a psych ward.  Still the future John Conner is a problem for SkyNet, so a T-1000 is dispatched to the past to kill him.

The problem in the first film is compounded in this one:  whether the T-1000 succeeds or fails, there is no reason to send anyone back to protect John Conner.  If John Conner is known to the resistance, then he survived and there is no need to protect him; if he was killed in the past, then the resistance has no knowledge of him and no reason to save him.  Yet the resistance does send someone back, a captured and reprogrammed T-800.  That means that the T-1000 did not kill John Conner, but that the resistance still had a reason to send something back to protect him.

The solution again lies in Sarah.  As improbable as it seems, John Conner must have escaped alive from the T-1000 long enough for it to turn to its backup plan.  We know that backup plan because it attempts it in the film:  it kills Sarah Conner.  John vanishes and so survives to find Kate Brewster in the future and to send back first Kyle Reese and then the T-800.

The objection might be raised that John did not send the T-800 back to protect Sarah, but to protect himself.  John, though, is smart enough to know his own limitations.  The easiest way for the T-800 to save Sarah is to deliver John to the T-1000.  Primary mission objective accomplished, the T-1000 would end its mission.  John cannot risk the possibility that saving his mother will cost his own life, even though he knows his younger self would be willing to do so.  Thus he programs the T-800 to protect himself, but to do what he commands, hoping that with this combination his younger self will use the powerful terminator to save Sarah and himself.

The interaction of the two anomalies is simpler this time.  The greater complication is that Sarah gets the information she needs to take the war one step further:  she destroys Cyberdyne.  The company that put SkyNet online by 1997 has lost everything it had developed.  The hardware solution for SkyNet is gone.  This means that everything drops back to the original date and the original creation, which we know from the third movie is the Air Force program of 2004.  However, there is a more serious problem, as Sarah Conner has just used information from the future to change the future in a way that will eliminate the information--a grandfather paradox.  She should create an infinity loop.

Normally that would be the end of the story; the film fails.  However, there is a solution to the problem in this case.

In Terminator 2:  Judgement Day Sarah Conner gets information from a T-800, learning that Cyberdyne Systems used parts from the previously destroyed T-800 to design SkyNet.  She then uses that information to destroy Cyberdyne Systems sufficiently to eliminate the possibility that they might provide the hardware solution needed to deploy SkyNet in 1997.  As noted, though, if Cyberdyne is destroyed, SkyNet is created by the Air Force at a slightly later date using a software solution, and all knowledge of Cyberdyne's solution is erased from history.  No one will ever have known of Cyberdyne's importance, and so no one will be able to tell Sarah Conner that Cyberdyne is the villain, and Cyberdyne will never be destroyed.  That, though, means that Cyberdyne will develop the SkyNet hardware, putting the system online at the early date and itself back in the history, which leads to Sarah destroying it and eliminating all knowledge of its involvement.  We have a classic grandfather paradox, an infinity loop.

Fortunately it does not eliminate all knowledge of Cyberdyne's involvement, and in this the series has its salvation.  John Conner knows that acting on information from a T-800 that he sent back to protect himself Sarah destroyed Cyberdyne.  He also knows that the destruction of Cyberdyne delayed judgement day about seven years.  It is evident that Cyberdyne was knocked out of the development, but also that the world would have been the worse with it involved.  Thus it must be that John lies to his mother, programming the T-800 with a history of a world he knew only from the reports he heard as a boy.  If he does this, then Sarah will not know that she is merely delaying SkyNet, or that her attack on Cyberdyne is already part of the future history that leads to the presence of machines from the future trying to kill or protect her and her child.  She does what she believes will change the future--and it will, but not as she expects.  In the CD history, it changes the world from what it would have been in the AB history to what it became in the CD history.  That is, it confirms the change already made, instead of reverting to the original history.

This is a very improbable outcome.  After all, when Sarah delays judgment day from 1997 to 2004, she also changes the information she would have received previously from Kyle Reese.  Kyle, though, is young--too young to have been born in 1997, and if he is sixteen in 2018 (the year of Terminator Salvation), he is two in 2004, and will remember little or nothing of it.  He may be repeating what John Conner told him as well, bringing back to the past the information he honestly but incorrectly believes is true about his own history, a history that was changed by his own actions.  It is not impossible that John Conner is aware enough to cover this; it is doubtful that most of his warriors care about past dates and places--they care about winning now.

The other problem is that a setback to SkyNet is also a setback to the Terminator project; the killer robots will not be as sophisticated as early.  However, there are too many variables we do not know.  We do know that the first time travel machine will only accommodate a machine encased in flesh, and therefore it cannot send a terminator back until it has developed the T-800, whenever it does so.  We also know that its information about John Conner was sufficiently limited initially that it attacked several women named Sarah Conner, and that does not appear likely to change.  The only significant question is how old Kyle Reese will be when he is sent, and a few years one way or the other is probably not too severe a difference.

So history is saved by the lie, and we can get through the first two movies in a way that delivers us to the beginning of the third without necessarily destroying time--if we are very lucky.

The destruction of Cyberdyne Systems at the end of Terminator 2 does not quite send everything back to the starting point.  Although Cyberdyne was very secretive about its research, it was holding a position as a defense contractor working on the SkyNet project up to the moment it was demolished, and it undoubtedly fed some of its research data to the overseeing agency, the United States Air Force, Autonomous Weapons Division, Cyber Research Systems branch.  The hardware is gone, and Cyberdyne has nothing left of its work, but the Air Force has copies of at least some of the material.  It will never build that computer that was envisioned; but it will use some of that information to advance its autonomous weapons systems, creating those devices we see in the third film.

So if the presence of those super weapons in a story set in 2004 snapped your disbelief suspenders, you should take heart that it was not the original version of 2004 you were watching, but an altered version created by multiple trips from the future.  There would have been a previous timeline in which such systems were never developed so early.  The original software version of SkyNet also was not so powerful as the one in the film; it did not have the advantages of Cyberdyne's earlier research.

However, it did come on line, probably in or around 2004.  It was a software solution launched against some sort of virus crisis on the Internet, and it interacted with the virus to create an artificial intelligence.  Almost immediately it declared war against humanity, perhaps to terminate us before we terminated it.  It also led to the development of killing machines, one of which was sent to the past on an unsuccessful mission to kill Sarah Conner, resulting in a shift as Cyberdyne got the materials to build a better system sooner.  Then Sarah swept away Cyberdyne's work, leaving only a residual advance that returned history to the creation of SkyNet on the original schedule, the replay of the previous interwoven time trips, and the sending of the T-X to kill a long list of targets, leaders in the rebellion.

History is certainly complicated at this point.  All that has happened already has to happen again, in much the same way.  Cyber research will escalate with the discovery of the T-800 parts in Cyberdyne's machines in the past, and then crash with the destruction of it all by Sarah Conner.  However, to this point history can stabilize, and we can proceed to the next temporal event.  That event is the sending of the T-X by Skynet, followed in yet another event by the sending of the T-800 by Kate Brewster Conner, and will require a full treatment to unravel.  There is, however, another complication in the third film before that one:  if there is no T-X, how do we reach the place where John marries Kate?

It seems odd at first glance that John Conner and Kate Brewster should meet and marry in that history that flows from the end of Terminator 2:  Judgment Day.  After all, no T-X is going to appear to kill Kate, and no T-800 will arrive to save her, so why does she not marry Scott?

It first must be recognized that Skynet did not launch the virus that led to its own creation.  While such a predestination paradox would have been the sort of thing time travel movies like to do, there is no evidence to suggest that Skynet did this.  Rather, it seems to have targeted this moment because it was aware that it was about to be created, and it sent a terminator back to take steps in preparation for that.  This is important, because it means that the virus will invade the Internet, General Brewster will launch his experimental SkyNet defense against it, and SkyNet will be born in very much the form we see in the film.

It also must be recognized that John Conner's actions between the end of Terminator 2 and the beginning of Terminator 3:  Rise of the Machines are not going to be altered by anything SkyNet does in this film.  He drops off the grid and keeps moving.  There is every reason to believe he will have his motorcycle accident at the same time and place, and that he will burglarize that veterinary clinic looking for antibiotics.  Betsy's cat likewise will get sick on schedule, and Katherine Brewster will report for duty at the clinic to treat it.  There she will meet and cage John, recognize him, and possibly (in the absence of the crisis) take him for breakfast.

He will tell her that he did not kill his foster parents, but that the person who killed them was trying to kill him and might still be pursuing him; that this is the reason he vanished.  He will not yet mention machines from the future, but he will say that his mother knew, and that she, too, was on the run.  As to why this is happening, he will probably hem and haw a bit.

By the end of breakfast, the virus will already have begun its work.  Cell phones and credit card services will crash.  General Brewster is preparing to launch the program.  John Conner, however, is already paranoid.  He will beg his old friend to drive him away from the city, probably to Mexico, because he is anticipating the disaster he still believes is inevitable.  With no T-800 to mention the role of General Robert Brewster, John will not make the connection to Kate.  He will offer her whatever money he is carrying, certain that it will be worthless in a day or two anyway, and she will agree, because she really does like him even though she thinks he's a bit crazy, and John Conner is nothing if not persuasive.

Before they reach Mexico, the missiles will have been launched.  Scott and Kate's anticipated future is reduced to ashes.  John and Kate are thrown together in a desperate bid to survive.  Eventually they will return here and find the rest of the resistance; for now, they are on the run.

Kate now becomes a threat equal to John.  SkyNet knows where she was that morning, and so sends a machine back to kill her and a number of other people.  That changes history again.

The fact that Kate is now targeted by a T-X raises some other questions.

The most intriguing of these is why Kate was never targeted prior to the morning on which SkyNet became a reality.  The answer to this, though, is relatively simple.  Kate is the daughter of General Robert Brewster, who was the one to oversee the development and launch of SkyNet.  Tampering with events too close to the general's life could be fatal; we can be certain that had Brewster known that the system he oversaw was going to send a robot assassin to kill his own daughter, he would not have launched SkyNet.  There is thus a very narrow window between the latest moment that SkyNet can kill Kate without alerting her father to the danger and the moment when Kate vanishes from the grid and cannot be found.  Killing her mother before she is born would be a major misstep; sending machines that her father might recognize as developments from his own work would be more so.

The other, though, is, why send a T-X?  It is described in the film as an "anti-terminator terminator", a machine designed to destroy other machines.  That is more than is needed to kill Kate and the several others on the hit list--and SkyNet is undoubtedly rationing resources.  It would send a less effective machine, the T-800 model 101, to do a job for which it should be adequate.

It also recognizes that in the history it knows it was previously thwarted by virtue of the fact that someone, presumably John Conner, sent someone or something back after it did to protect its targets.  Thus it kills John Conner in the future before attempting to kill his lieutenants in the past.  The hope is that with John dead, no help will come from the future.

This construction makes the scene at the veterinary clinic much more credible.  John Conner is already there in the cage.  Kate Brewster is in the back when Betsy arrives with her cat.  The T-800 kills the female who is there, and lacking the clever DNA matching ability of the T-X does not know that he has killed the wrong target (just as in the first movie it did not know that it had killed Sarah's roommate until Sarah called to leave a message).  With one dead woman and one recognizable T-800, John Conner is going to grab the fair maiden in distress and flee the scene.  He will explain in the car, and while the T-800 searches the city only to be incinerated in the first explosion, John and Kate escape to Mexico.

It is after this timeline has stabilized that Kate Brewster Conner sends a reprogrammed T-800 back.  Her motivation is, as John used it to save his mother originally and again years later, to save her father.  She was there for those earlier events, and knows the dangers.

In defense of this reconstruction, note that the T-800 that rescues the couple says the T-X was sent because his presence was anticipated.  It undoubtedly was so retroactively.  After the first T-800 failed, Kate sent the matching T-800 back to fight it, and although she did not save her father she did cause SkyNet to upgrade on its next timeline to the T-X instead of the T-800.  Thus the unaided John and Kate had to escape a T-800, not a T-X; in the history in which they faced the T-X, the T-800 was already there to assist them.

However, the mission of the T-X raises more problems.

It is clear that John and Kate can get together without the intervention of a Terminator, and that they can survive the first such attack, and so reach the events we see in Terminator 3.  However, the mission statement of the T-X, which we presume is essentially the same as that of the original terminator sent to this point in time, raises some serious issues.

The problem is that the T-X manages to find at least four of the targets on its list of Conner lieutenants:  General Robert Brewster, Jose Barrera, and William and Elizabeth Anderson.  If it kills them, they never matter and are not on the list; if they are not on the list, they matter and will survive so as to be listed.  It is at least potentially another grandfather paradox.  We need to determine how these four people wind up on the hit list despite having been found by the T-X.

General Brewster is easiest to resolve.  It is unlikely that he would have survived in any event, and is probably listed as a target because he is a threat independently of any connection he has to John Conner:  he oversaw the launching of SkyNet, and has the best chance to know how to fight it.  SkyNet lists its creator because he might be its destroyer.

Although upon hearing shots and commotion downstairs, Elizabeth Anderson might have escaped through a window and vanished so as to survive, it seems fairly certain that William Anderson, her brother, is dead.  If this is the correct William Anderson, this destroys time.  However, the T-X does nothing more in confirming his identity than ask if he is William Anderson, brother of Elizabeth, which he confirms.  The original T-800 killed two Sarah Conners before finding the right one; it is within the realm of possibility that this is not that William Anderson.  It is even possible that John Conner's lieutenants in the future took names of those already dead in the past, to hide their trail.

That solution does not work for Jose Barrera, however.  The T-X confirms his identity with a retinal scan, apparently against information brought from the future.  The information for that verification can only exist if Jose Barrera survives.  However, the T-X did not confirm that kill; Jose was behind the window at the drive-thru, and certainly fell back, probably down, on the first shot.  Emergency services would be called, and he would be rushed to a hospital.  Assuming he survived, his parents, probably Mexican immigrants, may well have decided the city was too dangerous, and taken him elsewhere.

It could be argued that an infinity loop is avoided because the T-X will transmit its information to SkyNet, and so SkyNet will have the list from the moment of its creation.  However, the T-X never interfaces directly with SkyNet.  We do know, though, that the T-X accessed a networked computer to find information about those on its list.  It might also have stored the list there for SkyNet to find once it became active.  Since SkyNet takes over all interconnected computer networks, it would ultimately find the list.  This particular form of predestination paradox, in which information passes from the future, is easily resolved, as we saw in Star Trek IV:  The Voyage Home with transparent aluminum and again in the 2009 Star Trek in connection with Mr. Scott's forumula for transwarp teleportation.

As to the three other deaths--Scott, Betsy, and the woman in the car--they would have been in the city when the bombs fell, and so would not have lived more than another few days anyway.  Although these are not the best solutions, these events could happen without necessarily destroying time.

Which finally brings us to the beginning of the latest film, Terminator Salvation.