The double-slit experiment is a classic experiment in physics that demonstrates the wave-particle duality of matter and the probabilistic nature of quantum mechanics. While it has profound implications for our understanding of the quantum world, it does not suggest that matter doesn't follow the rules of physics when it is not observed.
In the double-slit experiment, a beam of particles, such as electrons or photons, is directed towards a barrier with two narrow slits. Behind the barrier, a screen captures the pattern produced by the particles that pass through the slits. Surprisingly, even when the particles are sent through the slits one at a time, an interference pattern emerges on the screen, suggesting that the particles behave like waves and interfere with themselves.
When particles are not observed, they can exhibit wave-like behavior, and their properties, such as position or momentum, become described by probability distributions rather than definite values. The act of measurement or observation collapses this probability distribution into a specific value.
The implication of the double-slit experiment is that particles, at the quantum level, can exhibit both wave-like and particle-like properties. It challenges our intuitive understanding of classical physics, where objects are thought to exist in well-defined states. In the quantum realm, particles exist in superpositions, meaning they can be in multiple states simultaneously until observed.
However, it is important to note that the behavior observed in the double-slit experiment is specific to the quantum realm and does not apply to macroscopic objects. Everyday objects, including ourselves, follow classical physics and do not exhibit wave-particle duality.
The double-slit experiment and similar experiments have been extensively studied and confirmed over the years, providing a foundation for the development of quantum mechanics. Quantum mechanics is a highly successful and precise framework that describes the behavior of particles at the microscopic scale, allowing for the accurate prediction of experimental results. It remains one of the most well-tested theories in physics.