What is a Photon?
A photon is the carrier of the electromagnetic force and is the quantum form of all electromagnetic radiation. This includes, light, radio waves, microwaves, X-rays, gamma rays and more. The most common to humans is visible light, which we detect with the retinas in our eyes. However, if our eyes were tuned to radio waves we’d be able to see FM and AM radio waves, responsible for audio, travel throughout the air. Light, radio waves and the aforementioned wave types are based upon the same electromagnetic wave, but each one occurs at different frequency ranges. The complete electromagnetic spectrum is found below.
Electromagnetic Spectrum
The photon is said to be in ‘quantum form’ because the electromagnetic wave is not a continuous wave. It is made of discrete parts, called photons. This became apparent in the late 1800s during an experiment called the photoelectric effect.
Questions
- Why do photons have energy but not mass, yet particles have both energy and mass?
- How can photons create matter out of nothing in a process called pair production?
Explanation
In energy wave theory, a photon is generated by the vibration of particles, traveling perpendicular to the direction of vibration.
In the particles section, particles were described as waves of energy, creating standing waves from in-waves and out-waves. The out-waves of these particles are longitudinal waves, but when a particle vibrates, it also creates a secondary, transverse wave. A faster vibration causes a photon with a shorter wavelength and greater energy and a slower vibration causes a photon with a longer wavelength and lower energy. This results in the different types of waves seen in the electromagnetic spectrum (e.g. x-rays versus radio waves).
The photon is typically described as an electromagnetic (EM) wave, such as the image below. These are the two components of the wave (longitudinal and transverse). Longitudinal waves constantly flow from particles, causing an electric field even when a particle is not in motion. When a particle spins or vibrates, a transverse wave also forms and is recognized as the magnetic field.
EM wave of the photon
Photon Creation and Absorption
There are a handful of different ways that photons are both created by particles and absorbed by particles. But in all cases, it is a change of wave forms between longitudinal wave energy and transverse energy and vice versa. Unlike a particle which has wave centers that create standing, longitudinal waves measured as mass, the photon is a packet of traveling waves. Therefore, it has energy but not mass.
Waves may change forms, but they will be in full compliance with the conservation of energy:
- Longitudinal to Transverse – photon creation seen in emission from atoms (spontaneous and stimulated) and from particle annihilation
- Transverse to Longitudinal – photon absorption seen in electrons changing orbitals in an atom, being ionized from an atom, or the creation of a particle and antiparticle in the pair production process.
The detailed processes and explanation for these photon interactions is found on this page.
Where is the Proof?
Photon wavelengths and energies were calculated using the transverse equations. The equations for wavelength and energy were derived from the same energy wave equation as longitudinal energy for particles, which connects particles and photons and how they can transfer energy from one form to another (transverse to longitudinal and vice versa). The calculations include the following:
- Calculations
- Calculations of hydrogen photon wavelengths for ionization and orbital transitions
- Calculations of 250+ photon energies for ionization of hydrogen to calcium (neutral and ionized elements).
- Calculations of the conversion of particle energy to photon energy for annihilation, orbital transitions and ionization
- Explanations
- An explanation for the photoelectric effect and other photon creation and absorption processes matching experimental observations, including particle annihilation, pair production, Compton scattering and orbital transitions.
Video Summary