Light has the unique characteristics of behaving both like a particle and a wave at the same time. We discussed the wave theory of light earlier. However, light also has particle nature. Light is made of particles called photons. In physics, a photon is a bundle of electromagnetic energy. It is also referred to as a quantum of electromagnetic energy. Photons are zero mass particles without charge, which means they are electrically neutral.
The concept of light as discrete particles had been around for centuries. It was formalized in Newton’s construction of the science of optics. Yet, the 1880s saw an increased interest in the wave nature of light which had become evident, and scientists more or less ignored the particle theory. Even the term ‘photon’ was only coined in 1926 by Gilbert N. Lewis. Particle theory returned to the forefront of scientific discussions with Einstein’s experiments.
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