The explanation for the discrete bundle of electromagnetic energy, which we refer to as a photon, is rooted in the quantum nature of light and the theory of quantum mechanics. According to quantum mechanics, particles, including photons, exhibit both wave-like and particle-like behaviors.
In the case of light, electromagnetic radiation is typically described as a wave, with characteristics such as wavelength and frequency. However, when interacting with matter, light behaves as though it is composed of discrete particles, or photons. This behavior is observed in various phenomena, such as the photoelectric effect, where light can eject electrons from a material in discrete energy packets.
The quantization of energy in photons arises from the wave-particle duality of quantum mechanics. According to Max Planck's work in the early 20th century, energy is quantized and can only be emitted or absorbed in discrete amounts called quanta. In the case of light, the energy of each quantum is directly proportional to the frequency of the corresponding electromagnetic wave, as described by Planck's equation E = hf, where E is the energy, h is Planck's constant, and f is the frequency.
When a light source emits photons, each photon carries a specific amount of energy corresponding to its frequency. The energy of a photon cannot be divided further, and it behaves as a distinct entity during interactions with matter. This discrete energy transfer is responsible for various phenomena, including the emission and absorption spectra of atoms, the behavior of light in electronic devices, and the fundamental workings of technologies like lasers.
In summary, the explanation for the discrete bundle of electromagnetic energy, or photons, is derived from the principles of quantum mechanics and the wave-particle duality of light. Photons represent individual quanta of energy that are emitted and absorbed in discrete amounts, accounting for the particle-like behavior observed in interactions between light and matter.