👉 Light, a form of electromagnetic radiation, consists of particles called photons. These photons are massless, highly energetic particles that travel at the speed of light in a vacuum, approximately 299,792 kilometers per second. Photons are the fundamental particles that make up light and are responsible for its ability to carry energy and momentum. When light interacts with matter, such as atoms or molecules, it can be absorbed, emitted, or scattered, leading to phenomena like the colors we see in the sky (due to Rayleigh scattering) or the formation of spectral lines in stars. Photons can also exhibit wave-like properties, such as interference and diffraction, yet they are fundamentally discrete particles, each carrying a specific amount of energy proportional to its frequency, as described by Planck's equation (E = hν). This dual nature of light—as both a wave and a particle—underlies many aspects of astronomy, from understanding stellar spectra to studying the behavior of light in extreme cosmic environments.
