Ooooooh - thinking about time travel just hurts the head. And the funny thing is that equations treat time and space the same - so why would it be that we can imagine teleporting through space so easily but time travel gets complicated so quickly?
Anyone see the low-budget scifi called Primer? Available on NetFlix - a great film considering it was made for $7000. A great film regardless. But the way it makes your head hurt.... that seems so typical of time travel.
That aside - the thing to keep in mind about that article is that it applies to quantum states, not elephants:
“You can send your quantum state into the future without traversing the middle time,” said quantum physicist S. Jay Olson of Australia’s University of Queensland, lead author of the new study.
In ordinary entanglement, two particles (usually electrons or photons) are so intimately bound that they share one quantum state — spin, momentum and a host of other variables — between them. One particle always “knows” what the other is doing. Make a measurement on one member of an entangled pair, and the other changes immediately.
So you have to limit your imagination to what you know about quantum states - the Star Trek analogy involving Scotty doesn't apply so readily.
What does that get anyone? That's where the imagination really comes in and I must say fails me admirably. What kind of technology could you build with it? Undetectable signals (since they aren't present for the "middle time")? Feedforward loops (mechanisms that track states in the past in order to synchronize themselves with past events)? Past-time sensors that send data to a future receiver?
Basically they are quantum "echoes from the past" - kind of like a camera recording current events so they can be replayed later. But you aren't replaying them, you are receiving the signal directly through time.
Maybe.... you could put sensors in an environment where they wouldn't be able to send a signal or record either (for some reason) and have them instead beam the signal into the future. For example, measuring state within a device that is exploding (and would overwhelm a signal with EM or destroy a stored signal).... now why would you want to do that?
OK - how about back to quantum encryption? You encode data and send it into the future - it is effectively gone until that later time when it arrives and can be recaptured. Then it can be retransmitted forward again and the information disappears. That might be a good way to hide information.
Really, since you are stuck in quantum terms, the only thing worth considering is information - data - communications and computation.
Anyone else have a better concept for using time entanglement?