We know that our bodies and the world around us are composed to matter made up of tiny particles. But, what keeps these particles in some kind of organization, what dictates the movement and relationship of matter? According to the modern Standard Model, there are four fundamental forces of nature: gravitation, electromagnetism, and strong nuclear force and weak nuclear force nuclear forces.

Gravity is the weakest of the fundamental forces. This force attracts all matter to all other matter, and has a very long range of distance at which it is effective. For the most part, gravity accounts for the movements of celestial bodies. The clumping together of matter caused by gravity accounts for the formation of planets. Gravity also accounts for why apples fall from trees and hit scientists on the head. The force of gravity between two bodies of matter is proportional to the product of the masses of the two bodies divided by the square of the distance between the two bodies.

Electromagnetic force is a very pervasive fundamental force which accounts for electricity and magnetism. Electromagnetic force occurs between two charged particles and is carried by photons. This force, like gravity, is inversely proportional to the square of the distance between the two particles. Electromagnetic force is responsible for keeping electrons in orbit about the nucleus of an atom, and for the combination and bonding of atoms that come together to make molecules. This force is also responsible for electromagnetic waves, including light.

The weak nuclear force is responsible for all the byproducts of nuclear reactions. This force plays a part in radioactive decay, transforming nuclear binding energy into thermal energy and mechanical energy energy. The weak nuclear force is carried by three vector gauge bosons: W+, W-, and Z0. It has roughly one 1000th the strength of the strong nuclear force.

The strong nuclear force is the strongest of all the fundamental forces. The strong nuclear force is responsible for keeping together the protons and neutrons that make up an atom’s nucleus, and must fight with the electromagnetic force that repels protons from each other. This force is based on interactions between quarks (sub-particles that combine to form protons and neutrons) and is carried by gluons.