What are photons?

Photons are defined as the fundamental particles of light and other forms of electromagnetic radiation. They are unique in that they possess both particle-like and wave-like properties, a concept known as wave-particle duality. In essence, photons are massless particles that travel at the speed of light in a vacuum and carry energy quantized in terms of frequency and wavelength.

For example, when light interacts with matter, photons can be absorbed or emitted by atoms, leading to various phenomena such as the photoelectric effect, where electrons are ejected from a material upon absorption of photon energy. This characteristic of photons as carriers of electromagnetic energy is crucial in numerous applications, including lasers, solar cells, and telecommunications.

Understanding photons as particles of light is fundamental in fields such as quantum mechanics and optics, where they play a critical role in explaining how light behaves and interacts with different materials.