Photonenkonzept

The photon concept, also known as the particle theory of light, proposes that light can be described as discrete packets of energy called photons. This concept was a crucial development in understanding the dual nature of light, which exhibits both wave-like and particle-like properties. Historically, light was primarily understood as a wave, explaining phenomena like interference and diffraction. However, experimental observations such as the photoelectric effect and black-body radiation could not be fully explained by classical wave theory.

Albert Einstein's work in 1905, building on Max Planck's quantum hypothesis, was pivotal in establishing the photon concept. Einstein proposed that light energy is not emitted or absorbed continuously, but in discrete quanta. The energy of a single photon is directly proportional to the frequency of the light, as described by the equation E = hf, where E is energy, h is Planck's constant, and f is frequency. This revolutionary idea explained why light of a certain frequency is required to eject electrons from a metal surface in the photoelectric effect, regardless of the light's intensity. The photon concept has since become a fundamental pillar of quantum mechanics and has had profound implications for fields like quantum optics, solid-state physics, and cosmology.