The presence of a Killing horizon causes decoherence of a quantum system in a superposition of states. For an electrically charged system with a superposition of coordinates, this happens due to entangling photons crossing the horizon and carrying away information about the superposition. The connection of this process with black hole thermodynamics and entropy bounds is explored. It is shown that the apparent contradiction with entropy bounds is resolved if the entangling photons, while modifying the field on and inside the horizon, do not create a flux through it. The information stored in this field and not retrievable by an external observer leads to the decoherence of the superposition. Thus, the event horizon serves not only as a point of no return but also as a mechanism for erasing quantum correlations.
A quantum particle can be in two states at once—like a coin spinning, both heads and tails. Near a black hole, the event horizon—where spacetime curvature bends space and time to the extreme—acts as a one-way gate. A stray photon grazing this boundary 'photographs' the coin, forcing it to land on one side. The photon then crosses the horizon, carrying the snapshot into oblivion. Black holes store information on their surface, not inside—like a hologram. The photon's record gets added to the horizon's area, tweaking only the electromagnetic field without adding mass or energy. This obeys strict entropy laws discovered by Jacob Bekenstein and Stephen Hawking. The twist: a black hole's memory lives on a two-dimensional surface, a cosmic canvas where quantum possibilities vanish without a trace.
🎯 A black hole's information capacity is measured by its surface area, not its volume—a counterintuitive result that emerged from Bekenstein and Hawking's work.