Time travel is a beloved conceit in film-making because the medium is such a good fit for mucking around with the way time moves. We experience time more or less the way a film unfolds, with one moment (frame) following another in chronological order. But a film can easily reference an earlier or later moment, via flashback, foreshadow or, in the case of time travel, by transporting to it. This can get messy because our normal sense of cause-and-effect, logical structures, free will and so on gets turned on its head.
Traveling back in time can create logical paradoxes; forward in time, not so much. But what the best time-travel stories get right is that it’s possible to do both without upending logic. The particular (and perhaps particulate) nugget that works around temporal paradoxes is something known as a jinn, a term used by Russian physicist Igor Dmitriyevich Novikov. A jinn (Arabic, as in “genie”) is a subatomic particle that exists in a time-loop, a circular rather than linear timeline which has no beginning or end.
Physicist J. Richard Gott cites the jinn in Time Travel in Einstein’s Universe: The Physical Possibilities of Travel Through Time. Gott champions a cosmological theory that the universe created itself, utilizing a time-loop in its architecture. His math has been vetted by big-brained physicists, so we have confidence that the theory is at least theoretically (in the vernacular sense) possible. I love this theory. Gott asks, “Can the laws of physics allow the universe to create itself?” Answer: Damn skippy.
Look at this guy. The loop at the bottom of the model of the universe(s) is the jinn. (Or better to say, the loop is the architecture within which the jinn functions and exists.) I won’t go so far as to say his theory is “elegant” because how would I know? But it is not only an excellent response to people who play the infinite regress game — What created God then, huh? — it’s also a useful way to wrap one’s head around time travel.
Gott explains all this in Time Travel in Einstein’s Universe: The Physical Possibilities of Travel Through Time, and he gets his point across by referencing time-travel movies. One simple example he uses is from the 1980 film Somewhere in Time, in which a young playwright is given a timepiece by an elderly woman. The man takes the watch back in time 60 years and gives it to the same woman’s younger self. She hangs onto it until, in the fullness of time, she eventually gives it to the young playwright — a closed cycle of cause-and-effect. Gott writes: “So who made the watch? No one. The watch never went anywhere near a watch factory. Its world line is circular.” And, by the way — there are no paradoxes.
A jinn needn’t be an object — even a hamfisted one like a timepiece — it can be an idea. The very clever Back to the Future engages its audience to ask, ‘Who wrote the song “Johnny B. Goode”?’ and the answer depends on whom you ask. If you ask Marty McFly, he’ll say he learned it by listening to Chuck Berry, the artist who wrote it in 1958. If you ask Chuck Berry, he’ll say his cousin Marvin turned him on to the song in 1955 — by letting him hear it over the phone, as it was being played by Marty McFly. Both answers are correct. The composing of the song, at least in this fictional narrative, exists on a closed loop of time that spans 30 years. Or rather, it spans a timeless infinity.
Back to the Future gets into trouble when it strays from the jinn. It could have had Marty’s entire existence be the function of a jinn, wherein he causes his own birth by time traveling back in time, but instead the writers opted to have his tickety-tock travels be in conflict with his own existence. (Recall the silly fading photograph.)
The sorely missed animated sci-fi show Futurama played with this idea when the protagonist Philip J. Fry goes back in time, accidentally kills his grandfather, then sleeps with his grandmother, thus siring his own father and his own timeline. That closed loop of cause-and-effect within a jinn doesn’t sit well with our normal, intuitive experience of the way time (and events) unfold — “Take that, causality!” yells one character — but there’s nothing in there that defies physical laws, per se. The episode won an Emmy. (It should probably be mentioned that, while that the concept of the jinn has robust mathematical support in the sub-atomic world, it is supposed that macro applications of the idea — like whole human organisms whirling in the temporal loop — are up against excruciatingly long odds of probability.)
The late Roger Ebert wrote that the movie Looper (which employs the circular-timeline jinn as a central premise, hence the title) “sidesteps the paradoxes of time travel by embracing them.” That’s not a bad description of how a closed temporal loop can exist within an otherwise linear progression of time.
One last example. The first two Terminator movies employ a beautiful application of the jinn. Human existence is imperiled by Skynet, a global artificial-intelligence network that becomes self-aware. Who invented Skynet? Again, depends on your point of view. Humans seem to be the inventors, but they learned of the technology that makes Skynet possible only when a terminator — which is itself an arm of Skynet — travels back in time and leaves a piece of itself behind (an arm, as it happens). Thus the development of Skynet occurs within a closed loop of time, and the phenomenon creates no paradoxes. It’s worth noting that Skynet deployed its weaponry only when it felt threatened by the humans, who themselves were under threat by Skynet. Trying to pin the blame on who-threatened-whom is as pointless as figuring out where the technology came from in the first place. It always existed, within a jinn.
Subsequent installments in the Terminator franchise muck around beyond the parameters of a jinn, and the result is a hot mess. Reviewers were put off by the choppy internal illogic of the latest, Terminator: Genisys, and rightly so. Filmmakers, critics, and audiences should watch for the jinn in time-travel stories because it is a symptom that the writers know what they’re doing. For that matter, we should all be watching for jinns in everyday life, since they could be fucking with causality 24/7, which is to say a timeless infinity.