The double-slit experiment can be explained using both wave and particle concepts, depending on the level of description and the interpretation of quantum mechanics used.
When considering the behavior of light or matter in the double-slit experiment, it exhibits characteristics of both waves and particles. The experiment can be understood in terms of interference patterns created by the wave nature of the entities involved. When a beam of particles, such as electrons or photons, is sent through the double slits, the wave function associated with each particle interferes with itself, leading to an interference pattern on the detector screen.
The wave nature of the particles is observed through the pattern of light and dark bands produced on the screen, which resembles the patterns created by the interference of classical waves. This interference pattern arises due to the superposition and subsequent interference of the probability waves associated with the particles passing through the slits.
On the other hand, the detection of particles at the screen or detector as discrete entities implies a particle-like behavior. When individual particles are detected, they appear as localized "hits" at specific positions on the screen, suggesting that the particles behave like discrete particles rather than spread-out waves.
It is important to note that different interpretations of quantum mechanics offer varying perspectives on how to interpret and understand the wave-particle duality observed in the double-slit experiment. The Copenhagen interpretation, for instance, considers the wave function as a mathematical tool that describes the probabilities of measurement outcomes, without necessarily attributing a concrete physical reality to the wave or particle aspects. Other interpretations, such as the pilot-wave theory or the many-worlds interpretation, provide alternative explanations but are subject to ongoing debate and scrutiny.