Black holes and quantum experiments: A strange paradox that destroys quantum states

Physicists who made quantum mechanics and mysterious black holes lock horns with one another have deduced that conducting such an experiment can eliminate all quantum states in the vicinity. At a meeting of the American Physical Society held earlier in April, researchers said that performing a quantum experiment near a black hole is a recipe for a paradox that can simply damage any quantum state that dares to come close. 

To test the theory, physicists from Princeton University and the University of Chicago imagined an individual named Alice conducting the infamous double-slit experiment in a lab that orbits a black hole. This is a classic example of quantum physics in which a scientist sends a particle toward a pair of slits in a solid barrier. 

The findings of the study

If the particle's behaviour is not observed by anyone, an interference pattern of waves is seen on a screen placed on the other end of the barrier, appearing as if the particle simultaneously went through both sides at once. However, if a person or a device is able to measure the path of the particle and understand that it has gone through one of the slits, the quantum state of it being at two places collapses.

According to Science News, the team then imagined a second person, named Bob, inside a black hole’s event horizon. While he cannot escape, he will still be able to measure the particle, as per the laws of quantum physics. As Bob observes the slit that Alice's particle has reached, its quantum state would collapse and make Alice aware of Bob's presence.

The interesting part is that this is a paradox, as nothing happening inside a black hole should have any impact on or any communication with the outside world. “The paradox is that black holes are a one-way street. Nothing done in the interior of a black hole can affect my experiment that I do in the exterior. But we just made up a scenario in which, definitely, the experiment will be affected," said theoretical physicist Gautam Satishchandran.