Where Does a Photon Actually Get Its Energy From?

#physics #photon #cosmos Where does a photon actually get its energy from? This calm, two-hour deep-dive follows the warmth of sunlight all the way back to its source. Starting from the simple feel of the Sun on your skin, it builds the whole idea step by step: what a photon is, how Planck and Einstein discovered that light comes in lumps, how atoms make light by dropping electrons down an energy staircase, how the Sun converts mass into energy by fusion, and how a photon's energy can shift and even fade as it crosses the expanding universe. Along the way it visits Maxwell, Bohr, Fraunhofer, Compton, Feynman, and Emmy Noether, and ends at the honest, surprising edge of physics, where energy itself is not always conserved. A slow, complete look at the light you are standing in. Sources: a. Maxwell's electromagnetic theory of light and the unification of electricity, magnetism, and light. b. Planck's quantization of energy and Einstein's photon explanation of the photoelectric effect. c. Noether's theorem and the relationship between time symmetry and energy conservation in an expanding universe. #physics #photon #lightenergy #quantum #astrophysics #cosmology #redshift #planck #einstein #noether