*Photons* are also called light [[Quantum Mechanics|quanuta]] or light particles and are the energy packets that make up electromagnetic radiation (such as visible light). The energy of a single light particle is determined solely by its [[frequency]]. Let's start with a quick historic tour: in the 1870's Young performed his famous [[Double Slit Experiment|double slit experiment]] and physicists were convinced that **light is a wave**. A few years later, however, experiments like measurement of the spectrum [[Black Body Radiation|black body radiation]] or the [[Photo-electric Effect|photo-electric effect]] suggested that **light is made out of particles**. In both cases, energy had to be transferred in [[Discreteness|discrete]] packages, something that a [[Wave|wave]] cannot accomplish. These two explanations together (wave and particle) are sometimes called [[Wave-Particle Duality|wave-particle duality]]. In the end, neither of them is correct. [[Light]] is described by [[Quantum Mechanics|quantum mechanics]] and both sets of experiments are explained in this framework. >[!read]- Further Reading >- [[Light]] >- [[Wave]] >- [[Wave-Particle Duality]] >[!ref]- References