An observer hiding inside a black hole can eavesdrop on quantum objects outside itvan van/ShutterstockQuantum eavesdropping is possible across a black holes event horizon, one of the most impermeable cosmic boundaries at least in one direction.Daine Danielson at the University of Chicago, Illinois, wanted to know how the structure of space-time, the fabric of our reality, influences quantum objects. This led him and his colleagues to a thought experiment where two people, Alice and Bob, end up separated by one of space-times most extreme objects.