The double-slit experiment is a fundamental demonstration in quantum physics. When light passes through two parallel slits, it creates an interference pattern on a screen, proving light's wave nature. This experiment challenges our understanding of reality at the quantum level.
The interference pattern emerges because waves from the two slits travel different distances to reach each point on the screen. Where the path difference equals a whole number of wavelengths, constructive interference creates bright fringes. Where it equals half wavelengths, destructive interference creates dark fringes.
The most mysterious aspect is that even individual particles create the interference pattern over time. Each particle seems to pass through both slits simultaneously and interfere with itself. This quantum superposition challenges our classical understanding of reality.
The observer effect demonstrates that measurement fundamentally changes quantum behavior. When we place a detector to see which slit the particle uses, the wave function collapses and the interference pattern vanishes. Instead, we observe classical particle behavior with two distinct bands on the screen.
The double-slit experiment fundamentally changed our understanding of reality. It demonstrates wave-particle duality, quantum superposition, and the observer effect. These discoveries form the foundation of quantum mechanics and reveal that the microscopic world operates by rules completely different from our everyday experience. This experiment continues to inspire new technologies and philosophical discussions about the nature of reality.