The Standard Model - 5. Force Carriers

The Interractions, their force carriers and what they act on.

We've identified some of the constituents of matter that make up our Universe however now we need to know how they interact. Every force (or 'interaction') in our Universe is governed by the force carriers. The four force carriers we use in the Standard Model are Gluons (which carry the strong force), Photons (which carry the electromagnetic force), The W and Z bosons (which carry the weak force) and the questionable graviton (which carries the gravitational force ... or gravity). All forces in the world exist because of these four interactions, for example: nuclear decay, magnetism, friction etc.

1. Gravity: The Gravitational Force depends on the Graviton - a particle that is predict to carry gravity. However this particle has never been observed and so it's existence is questionable. If it does exist though, it is thought to have no mass and no charge. All known matter is affected whether directly or indirectly by gravity.

2. The Weak Force: One carrier for the weak force, the W boson can be both positively or negatively charged while the other; the Z boson, is neutral. The carriers have a lot of mass compared to some particles which makes the weak force ... well a 'weak' force. The weak force is responsible for decaying leptons and large quarks into smaller lighter leptons and quarks. Weak force and electromagnetic can be summed up in one section in the standard model as 'Electroweak', this is because at extremely short distances the strength of these forces has been observed as similar.

3. Electromagnetic: Photons are the carrier for electromagnetism, as well as 'carrying' the light that we see around us. This force causes same-charged things to repel and things which hold an opposite charge to react - so this interaction governs such forces as friction and magnetism. The photon has no mass and travels at a constant 300,000,000 meters per second (or the speed of light) in a vacuum.

4.Strong Force: Gluon's are the carriers for the strong force and they don't have mass or charge. They carry a special property which bounds quarks together. Since quarks make up protons and neutrons, these elements of matter are also held together by the strong force as without their constituents being held together, they would not function.

Thanks for reading another section on Particle Physics and The Standard Model, Chris.