Open Season

I was thinking about Hawking radiation the other day (briefly, that’s when a particle-antiparticle pair spontaneously emerges from the vacuum not far from the event horizon of a black hole. Before the particles can recombine, one gets sucked down into the black hole as the other flies away - hence, the appearance of radiation). I wondered, could information be destroyed by this process if it involved a pair of quantum-entangled particles? (Briefly, entangled particles are connected in some as-yet-unclear way so that when you measure some property of one particle, the other one takes on a corresponding state - seemingly instantly, no matter how far apart the particles are. This is weird, but it’s been experimentally verified endless times).

Here’s the experiment. Suppose I make a pair of entangled photons in the lab (that’s pretty easy to do). Let’s call the photons A and B. I’ll keep A in a bottle (speaking abstractly, of course) and I’ll send B into a black hole, where it disappears behind the event horizon. Are the particles still entangled? When B disappears behind the event horizon, is any information lost or destroyed? Is there a net change in the information in the universe? If I now measure some entangled property of photon A (polarization, for instance), will B take on the complementary state, even though it’s behind an event horizon? Pushing the question, suppose a friend travels into the black hole first (abstractly speaking, again) and measures the polarization of photon B when it arrives. Would A, back out here in my lab, then take on the complementary state? If so, would that mean information was flowing out of the event horizon and into my lab?

I’m a writer, Jim, not a physicist. I do know that we can’t use entanglement all by itself to communicate, which implies it doesn’t contain information, but we can use entanglement for real-world procedures like quantum cryptography. So I wonder if the entangled particles remain entangled even when their communications channel is removed.