Force carrier

The fundamental forces, along with their corresponding force-carrying particles, serve as the building blocks of nature.

  • Each fundamental force is conveyed by a distinct particle type known as a force carrier. These carriers are responsible for transmitting forces between pairs of particles.
  • To get on board with this, imagine the behaviour of individual subatomic particles, such as electrons or photons, and how they interact with each other in pairs.
  • For example:
    • An electron is a subatomic particle that has a negative electric charge. It constitutes one of the three particles in atoms.
    • A photon is a particle of electromagnetic radiation with no mass and travels at light speed in a vacuum.
    • The subatomic photon is the force carrier of all forms of electromagnetic radiation, including visible light, radio waves, microwaves, infrared radiation, ultraviolet radiation, X-rays, and gamma rays.
    • Photons carry the electromagnetic force between charged subatomic particles.
    • When two particles like electrons collide, the first electron emits a photon particle, which is then, subsequently, absorbed by a second electron. This emission-absorption event is termed an interaction, resulting in both electrons repelling each other and altering their trajectory. The transfer of energy and momentum between the electrons illustrates the electromagnetic force in action.
  • The concept underpinning force carriers is that everything in the universe is in perpetual motion, akin to billiard balls constantly colliding with one another.
  • The Big Bang initiated the motion of everything and the principle of universal motion asserts that all objects remain in constant motion, driven by the four forces of nature.
  • In an interaction between two electrons that are in motion and collide with one another, the electrons can exchange energy and momentum through the emission and absorption of photons.
  • This can happen in one of two ways:
    • One electron can emit a photon and the other electron can absorb it.
    • One electron can absorb a photon and the other electron can emit it.
  • The amount of energy and momentum that is exchanged depends on the photon’s wavelength. Photons with shorter wavelengths have more energy and momentum than photons with longer wavelengths.
  • For example, if two electrons collide and one electron emits a high-energy photon, the other electron can absorb the photon and gain a lot of energy. This can cause the other electron to move much faster as it is repelled.
  • The force carriers for the four fundamental forces are as follows:
    • The force carrier for electromagnetic force is the photon.
    • The strong force uses gluons as force carriers. Gluons, being massless particles, bind quarks together.
    • The weak force utilizes the W and Z bosons as force carriers. These bosons, possessing mass, interact with the weak force. They play a role in radioactive decay and some aspects of nuclear fusion.
    • The gravitational force. The force carrier for gravity remains elusive. The graviton is a theoretical particle suggested to be the force carrier for gravity. While undetected so far, it is believed to be a massless particle travelling at the speed of light.