A non-contact force refers to the force that acts upon an object without being in physical contact with it. A field is always linked with a non-contact force and can be represented using vector fields.
Unlike contact forces, the bodies need not be in contact with each other, which is also not linked with the field. Non-contact forces are of four major types, which are given below
It is the force of attraction that exists between all bodies that have mass. Gravitational force exists everywhere in the universe and on earth. It is due to the gravitational force that we can stand and walk on earth. The range of gravitation is infinite, but it gets weaker as we move away from it.
It is the weakest force in nature but has the most extensive range. Gravitational force is found everywhere, as most of the bodies in the universe have mass. It helps in controlling the direction and trajectories of planets. Gravity allows the planets to move in a fixed path around the sun and the satellites to move around the planet.
The gravitational force of different planets and satellites is different. In the case of the earth, the gravitational force is 9.8 m/s2. And on the moon, it is 1.62 m/s2.
Newton gave a relation between the gravitational force, the mass of objects and the distance between them. According to him, the gravitational force experienced by the objects is inversely proportional to the square distance and directly proportional to the mass of the two variables.
This is a non-contact force that exists between charged particles. It can pull or push different objects without being in physical contact with them. It is similar to gravitational force, the only difference being that it acts between charges. Like charges repel each other, whereas unlike charges attract each other. The study of electric charges at rest is called electrostatics.
Coulomb gave a law to calculate the electrostatic force between two particles. According to him, the magnitude of electric charge between two point charges is directly proportional to the product of the magnitude of their charges and inversely proportional to the square of the distance between them.
It is also called weak interaction. It occurs due to the decay of unstable subatomic particles. It involves the β decay of a neutron, which results in the decay of a neutron to give rise to a proton, emission of a β particle and an uncharged particle called the neutrino. This process of decay of β particles results in fusion reactions, like supernovas.
This force is stronger than gravity, but its range is comparatively lower. In comparison to electrostatic force, it is nearly 100,000 stronger. It plays an essential role in the creation of the universe and stars.
This is the strongest force in nature and has a very short range, like a weak nuclear force. This force is responsible for binding the nucleus and proton together, which results in the formation of atomic nuclei. It further helps in providing stability to the matter. Strong nuclear force can facilitate both fission and fusion reactions. Due to its huge amount of power, it is used to make nuclear bombs, and also its fusion produces a large amount of energy in the nucleus of the sun.
It is made of quarks that are held together due to its strong force. These quarks are the fundamental particles of protons and neutrons. In comparison to the electromagnetic force, it is about 140 times stronger. And about a million times stronger than the weak nuclear force.
These were the 4 major non-contact forces in nature. Another force that can be considered as a non-contact force is the Casimir effect. It is named after Dutch physicist Hendrick Casimir. It arises from quantum fluctuations.
It acts in confined spaces on the boundaries of a macroscopic material, like two close uncharged conducting plates. Modern physicists apply this concept in microtechnology and nanotechnology. According to this theory, the sum of all the photon modes in zero-point energy in a vacuum is infinite.
The bottom line is, unlike contact forces, there are four major non-contact forces. The strongest force is the strong nuclear force, and the most long-ranged is the gravitational force. The Casimir effect is still being considered as a non-contact force in some situations and places.