Accidentally hit my head on the toilet and came up with a flux capacitor, jokes aside, but here is a potential patent for one?
You see a double split experiment, where a particle is determined as an wave or an particle depending on the observation of it.
The idea is, Send this light down a tunnel (Bounce it back or forward, or a long of mirrors or w/e that slows light down as much as possible might have to be pretty big),
then into the double slit, of which the screen has an interference pattern.
Now here's the beauty, determine its a particle or wave at the double slit, (wait into experiment done), then look under the box. It should read a 0 or 1 according to what the light ends up being.
So in theory, this should send the information back a few seconds?