What are the four fundamental forces and how are they related? How do they differ?
1 Answer
The four fundamental forces are quite different, however it is thought that they can be unified.
Explanation:
The electromagnetic force describes the interactions between charged particles. Electricity and magnetism were unified by Maxwell into electromagnetism. Electromagnetism also describes light and the forces between charged particles. Electromagnetism has a long range.
The weak nuclear force described radioactive beta decay. This is where a proton is converted into a neutron, a positron and an electron neutrino. It also converts a neutron into a proton, an electron and an electron anti-neutrino. The weak nuclear force operates at very short range.
Electromagnetism and the weak nuclear force have been unified by the electroweak theory. The two forces are very different at low energies but are unified at very high energies.
The residual strong nuclear force binds protons and neutrons into atomic nuclei. It is called residual as it is actually an aspect of the colour force which binds quarks into baryons and mesons. It has a short range as it binds adjacent protons and neutrons.
A goal of modern physics is to unify the electroweak force and the colour force into a Grand Unified Theory (GUT).
Gravity is not actually a force, though it behaves like a force as long as masses and velocities are not to high. General Relativity describes gravity is the curvature of 4 dimensional spacetime.
An even bigger goal of physics is to have a Theory Of Everything (TOE) which unifies gravity with a GUT.
