“…the fact of quantum entanglement is this: If one logically inexplicable thing is known to exist, then this permits the existence of all logically inexplicable things.”
– Brian McGreevy, Hemlock Grove
Imagine a subatomic collision that produces two electrons. Due to conservation of spin, we know that one of the electrons has “up” spin, and the other has “down” spin — but we don’t know which is which. Now isolate the two electrons from interaction with other particles and separate them by an arbitrary distance. At this point you have two electrons, each in a superposition of states. Because we don’t know the spin of either electron, they both behave as if they could be have either one.
But here’s the fun part: when you measure the spin of one particle, the waveform collapses, and it no longer behaves as if it could have the other spin. Furthermore, at the same instant, the other particle’s waveform collapses as well. This is an example of the quantum phenomenon known as entanglement.
Since the knowledge transfer implied by this waveform change seems to occur faster than the speed of light, we can theoretically use it to implement all kinds of useful SF devices, especially the ansible. Time being what it is, however, anything that happens faster than the speed of light could lead to all manner of confusion in time-ordering of events, and smart people say it can’t be done.
This has led me to a more interesting series of thoughts about the nature of time. Specifically, what if the future is not as a known (or unknown) series of events, but is instead a quantum superposition of all possible states? When we experience something, it collapses the waveform associated with that event, and it becomes fixed — but so does the waveform of everything connected to that event, which affects other quantum states, and so forth. We as sentient beings experience these transitions as a forward progression in time, and our interaction with these transitions as free will.
In my latest short story, “Entanglement,” I combine these two ideas into a hard-SF justification for prophecy. If the Prophet is himself somehow entangled with events in the future, then his awareness of those events “measures” the local waveform, thereby forcing the waveform associated with the future event to collapse. In a way, it is his very knowledge of the future that causes the future to occur.
This same theory, extended backward in time, may lead to a situation where the past becomes equally nonexistent whenever it loses its causal connection to the present. Those who fail to remember history shall doom it to no longer exist. But that’s a story for another day.