Light can exhibit both wave-like and particle-like behavior, depending on the experimental setup and the specific phenomenon being observed. The wave nature of light is well-established and supported by numerous experiments and theoretical models.
In the wave model of light, light waves are described as propagating disturbances in an electromagnetic field. According to this model, light waves can exhibit various properties, including interference and diffraction. When light passes through a small opening or encounters an obstacle, it can diffract or spread out, leading to the formation of interference patterns.
The bright spot interference pattern you mentioned is commonly observed in experiments involving the double-slit setup, where light passes through two closely spaced slits. The pattern consists of alternating bright and dark regions on a screen placed behind the slits. This phenomenon occurs due to the interference of light waves. When the peaks of two overlapping waves coincide, constructive interference occurs, resulting in bright spots. Conversely, when the peaks and troughs of two waves overlap, destructive interference occurs, resulting in dark spots.
Regarding steel beads, it's important to note that interference patterns are typically observed with coherent light sources, such as lasers, where the waves have a fixed phase relationship. Steel beads are not commonly used in interference experiments. However, interference patterns can be observed using other materials and setups, such as using thin films, diffraction gratings, or multiple slits.
It's worth mentioning that while the wave model provides a useful framework to understand the behavior of light, the particle-like nature of light is also demonstrated by phenomena such as the photoelectric effect and the observation of discrete energy levels in certain experiments. This duality between wave and particle behavior is a fundamental aspect of quantum mechanics, and the wave-particle duality of light is a well-established concept.