NOTE: I’m presenting this as a movie plot, not actual science. I’m a programmer, not a physicist. I’m fully aware that I have no idea how physics works and that everything below is probably complete nonsense. Which is why it would be perfect for Hollywood. Okay, carry on.

So, here’s the premise: Light moves at, well, light speed. The closer you get to moving at light speed, the slower subjective time moves. Which means that for light, time doesn’t move at all. Which is probably part of why it’s both photons (particles) and light waves (energy); if there’s no time there is no significant difference between the two.¹

Okay, so here’s the sci-fi movie upshot of all this, using a lot of tech wizardry that makes very little sense: A scientist discovers a way to entangle photons, so that when you send a concentrated beam of photons out the state of each emitted photon is mirrored in a trapped photon. (Remember: this is movie science, not real science) the kicker is that the state of the emitted photon is identical to the trapped photon until it hits something, which is when it starts experiencing non-light-speed time again, and is also useful because light, moving at light speed doesn’t experience subjective time at all, so the moment when it strikes something, even if that is far in the (observer’s subjective) future, is reflected in the trapped photon instantly. By reading the state of your trapped photons, you can observe events in more-or-less real time by using a really powerful computer, probably with code scrolling across its screen at all times.

Now we mix in the science magic that non-scientific people call “quantum” and we assume that you can interpolate details about the surroundings of the emitted photon from its state when it strikes something and viola! You’ve invented a way to look forward in time. By bouncing the photon off of things at various distances from the earth (reflection doesn’t cause the photon to resolve its state because shut up) you can observe future conditions at various points in the future. And thus quasi-scientific movie magic is born.

From here you can do various things with explorations of the deterministic nature of the universe, either saying that everything remains the same no matter what you try to do to change them (essentially turning light into a sci-fi version of the Oracle at Delphi) or you can have the light beams show that individual changes can alter the course of history. Or for even more fun you can throw some vaguely understood concepts about the act of observation changing that which is observed and say that us spying on the future is itself changing the future. The fact that we’re also changing that future’s past only serves to further complicate the relationship between the two events.

And then, as the final twist (or material for the sequel) you can reveal that the future is using the same light beams to spy on us.

Any major movie studios wishing to do a plot treatment can leave a comment below. I’m reasonable.