decoherenciát

Decoherence is a fundamental process in quantum mechanics that explains the transition from quantum behavior to classical behavior. It occurs when a quantum system, which can exist in multiple states simultaneously (superposition), interacts with its environment. This interaction effectively "measures" the system, causing its superposition to collapse into a single, definite state.

Imagine a quantum particle in a superposition of being in two different locations at once. If this particle interacts with the surrounding air molecules or photons, these environmental particles become entangled with the particle's state. This entanglement means the information about the particle's superposition is no longer solely contained within the particle itself but is spread out into the environment.

As a result, the coherence of the quantum state, which is the property that allows for superposition and interference, is lost. The system appears to behave classically because its quantum nature has been diluted and lost to the vastness of its surroundings. Decoherence is therefore crucial for understanding why we don't observe macroscopic objects in superpositions. It's the reason a cat is either alive or dead, not both. The process is continuous and happens at all scales, but its effects become overwhelmingly apparent for larger, more complex systems.