Quantum Entanglement Of Photons That Don't Exist At The Same Time

Here's how you do it!

Yes, you read that right and it's not April 1st. It seems that experimenters in Israel have shown that they can entangle two photons that don't even exist at the same time.

One of the researchers on the project, Hagai Eisenberg, said. "There is no moment in time in which the two photons coexist," he says, "so you cannot say that the system is entangled at this or that moment."

Yet, the phenomenon definitely exists.

Although they've only done this in one temporal direction, into the future, can it be long before they try to figure out a way to test if works the other way, too?