Physicists are fascinated by the idea of "information loss" because it challenges one of the core principles of quantum mechanics: unitarity. In simple terms, unitarity means that the total information about a system (like the state of particles in the universe) must always be preserved, even if the system changes over time. You should, theoretically, be able to trace backward and recover all information about the system’s past, no matter what has happened.

Now, here’s where black holes come into play: when something falls into a black hole, classical physics tells us that the information about it seems to disappear forever. This creates a tension between general relativity (which governs black holes) and quantum mechanics, which insists that information can’t just vanish. This mystery is called the black hole information paradox.

The "information loss" problem specifically arises during the process of black hole evaporation through Hawking radiation. Stephen Hawking proposed that black holes emit radiation over time due to quantum effects at their event horizons. Eventually, they can shrink and vanish completely. But here’s the kicker: Hawking radiation is seemingly random and doesn’t carry information about what originally fell into the black hole. So, when the black hole disappears, does the information just… go poof? That would violate unitarity!

This paradox has huge implications for how we understand the universe and its laws. If information is lost, it means we need to rethink some foundational ideas in physics. But if information isn’t