There are 4 forces that govern all the phenomena observed in the universe. They are the strong nuclear, the electromagnetic, the weak nuclear and the gravitational force. The first 3 are forces of the microscopic world and gravity is the macroscopic force. But, how are these forces actually mediated?
Some of you are aware of the terms gravitational field and electromagnetic field. The field is the area under which some object exerts its influence. Now the question is how does this “field” actually exert its influence?
The Force Particles
All forces have a force carrying particle associated with them. For the electromagnetic force, the force carrying particle is the photon. For the strong force, it is the gluon particle and for the weak force it is the W and Z Boson. The force carrying particle for gravity is the graviton which is still a theoretical particle.
Particles exert forces or interact with each other through the exchange of force carrying particles. For example two electrons approaching each other repel when one releases a photon and the other absorbs it. This is the electromagnetic interaction between electrons. Similarly, quarks are held together inside protons due to constant release and absorption of gluons.
These interactions are easily understood through Feynman diagrams. One is given below-
The two electrons approaching each other are the in-going electrons. One electron emits a photon which is depicted by wiggly line and the is absorbed by the second electron. the two electrons moving away from each other are the outgoing electrons. Feynman Diagrams will be discussed in more detail in a later article.