Preamble

Abstract

The physics of light is one of the oldest fields in science and has fascinated many well-known scientists over the last centuries. In the 17th century, a famous contradictory discussion arose when Newton introduced the concept of particles of light, while Huygens described light as a wave-like phenomenon. The latter description was successfully tested in many classic experiments, e.g. the double-slit experiment from Young, and reached its peak popularity in the 19th century. Maxwell formulated his famous description of light as an electromagnetic wave, which might be considered as one of the greatest achievements in physics. However, in the early 20th century, the model was questioned again when Einstein reintroduced the concept of particles of light, nowadays called photons, to explain the photoelectric effect. His explanation can be considered (along with Planck’s quantum hypothesis in the description of black body radiation) as one of the starting points of quantum mechanics, the most successful theory we know today. This very brief (oversimplified and incomplete) historical note shows that light has often been in the heart of many fruitful discussions that have yielded a better understanding of physics.