👉 Widespread light particles, often referred to as photons, are fundamental constituents of electromagnetic radiation and are considered the basic units of light. These particles are incredibly small, with wavelengths ranging from approximately 400 nanometers (violet) to 700 nanometers (red), corresponding to very high frequencies and energies in the electromagnetic spectrum. Photons are massless, meaning they have no rest mass, which allows them to travel at the speed of light in a vacuum, approximately 299,792 kilometers per second. They carry energy and momentum, and their interactions with matter—such as absorption, emission, and scattering—are central to phenomena like photosynthesis, vision, and the operation of solar cells. Despite their minuscule size, photons play a crucial role in our understanding of the universe, from the behavior of atoms and molecules to the structure of stars and galaxies.
