What are the relative strengths of the four fundamental forces?
1 Answer
The forces have different ranges and intensities, so any ranking is somewhat subjective.
Explanation:
Gravity is often considered the weakest force. The reason being that it has negligible effect at the atomic scale. Gravity however has a very long range. It is responsible for the formation of stars, planets and galaxies. It is responsible for the motions of bodies within solar systems and the motions of stars in galaxies.
Actually gravity is not a force it is the curvature of spacetime. Einstein showed that there was an equivalence between gravity and acceleration. This means that as long as objects aren't too massive or travelling at high speeds gravity can be described as a force using Newton's laws.
The weak nuclear force is responsible for radioactive beta decay. It has a very short range and is confined to the atomic nucleon scale. It is also very slow acting which is why some radioactive nuclei take a very long time to decay. A typical weak interaction is a neutron decaying into a proton and a W boson. The W then decays into an electron and an electron anti-neutrino.
The electromagnetic force controls the interaction between charged particles. It also describes electricity and magnetism. The electromagnetic force is responsible for way electrons and an atomic nucleus form atoms and how electrons interact in chemical reactions.
The strong nuclear force is responsible for binding protons and neutrons in to atomic nuclei. It is considered the strongest as it overcomes the effect of the electromagnetic force which causes positively charged protons to repel each other. Actually the strong nuclear force doesn't really exist. It is a residual effect of the colour force which binds quarks into nucleons.
