Universal Forces

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Introduction to Universal Forces

The forces that occur all around the universe are called the universal forces. There are four types of forces also called the 4 fundamental forces. 

These Four Forces of Physics Are Called Universal Forces. They Are as Follows:

  • Strong nuclear force

  • Electromagnetic force

  • Weak nuclear force, and 

  • Gravitational force. 

Where a strong nuclear force is the strongest, and gravity is the weakest. The strong force has an effect on small distances, while gravity acts over large distances.

On this page, we will learn about four types of forces in detail.

Do You Know?

For a very long, scientists have been trying to combine all the forces into a single force. 

However, in 1864, a Scottish scientist in the field of mathematical physics named James Clarke Maxwell FRSE FRS was able to combine the electrical and the magnetic forces into the electromagnetic force under Maxwell's equations. 

Scientists also combined the electromagnetic and the weak force into the electroweak force but could not combine any of the other forces so far.

Four Forces in Physics                  

The fundamental forces a.k.a fundamental interactions of physics. These are the ways in which individual particles interact with each other. 

It is results that every single interaction found taking place in the universe can be broken and described by the following four types of interactions:

  1. Gravity

  2. Electromagnetism

  3. Weak Interaction or a Weak Nuclear Force

  4.  Strong Interaction or a Strong Nuclear Force

(Image to be added soon)


Out of the 4 fundamental forces, gravity has the farthest reach but has weak magnitude.

It is a purely attractive force that can reach the empty space in which two masses joined by an imaginary line attract toward each other. This invisible force keeps the planets orbiting around the sun and the moon around the Earth.

Gravitation is characterized as the theory of general relativity, which defines it as the curvature of spacetime around an object of mass. This curvature, in turn, creates a condition where the path of least energy passes towards the other object.


Electromagnetism is the combination of electricity and magnetism. It is an interaction of particles with an electrical charge. Statically charged particles interact through electrostatic forces, while charged particles in motion interact through both electrical and magnetic forces.

Do You Know?

For a very long time, after uniting the electric and magnetic forces into electromagnetic forces, in the 1940s, quantum electrodynamics is formed by the unity of electromagnetism with quantum physics.

Electromagnetism has been referred to as the most prevalent force in the world because it can affect things at a reasonable distance and with a fair/huge amount of force.

Weak Nuclear Force

The weak interaction seems to be a weaker force; however, it is a very powerful force that acts on the scale of the atomic nucleus. It is responsible for the occurrence of phenomena such as beta decay. 

It has been combined with electromagnetism as a single interaction called the "electroweak interaction." 

Here, the weak interaction is mediated by the W boson, which is two types, viz: W+ and W- bosons, and also the Z boson.

Strong Nuclear Force

The strongest of all the forces is the aptly-named strong interaction; this force keeps nucleons, i.e., protons and neutrons bound together. 

For example, in the helium atom, strong enough is needed to bind two protons together even though their positive electrical charges cause them to repulse each other.

In nutshell, the strong interaction allows particles like gluons to bind together, quarks to create the nucleons in the first phase. 

Gluons can easily interact with other gluons, which gives the strong interaction at a theoretically infinite distance, although its significant events occur at the subatomic level.

Four Types of Forces

The below table enlists the properties of 4 fundamental forces:

Properties of Fundamental Forces

Name of the Force

Relativistic Strength

Range in Meters

Particles’ Name

Strong interaction/nuclear


2 x 10-15





Weak interaction/nuclear







Unification of Fundamental Forces

  • Many physicists believe that all 4 fundamental forces are, in fact, the versions of a single underlying unified force that has yet to be discovered. 

  • Just like electricity, magnetism united to form electromagnetism, similarly, the weak force was unified into the electroweak interaction, they work to unify all of the fundamental forces.

  • Sir Isaac Newton realized that the gravitational force described an apple falling from the tree can also describe the moon’s orbit around the Earth. 

  • Later in the 20th century, Steven Weinberg, Abdus Salam, and Sheldon Lee Glashow discovered that at higher energies, the electromagnetic force and the weak force combine to form a single electroweak force.

  • The work on unifying gravity with the other three fundamental forces is called quantum gravity. It suggests the existence of a virtual particle called the graviton that would be the mediating element in gravity interactions. To date, gravitons are imaginary particles, and no theories of quantum gravity have been adopted universally.

FAQ (Frequently Asked Questions)

1. Is gravity a contact or non-contact force?

A non-contact force on the body without coming in contact with it. The most familiar example of this kind of force is gravity.

If the force acting on the body of mass ‘m’ is F, then the force of gravity or weight is given by:

                    F = mg

Where g is the acceleration due to gravity whose value = 9.8 m.s-2.

2. What are three examples of non-contact force?

Below are the examples of the non-contact force:

Example 1: 

The electricity supply at your homes is because of an invisible/intangible force that acts on electrons running in the wires of your appliances.  Do you know how it occurs?

A wire contains millions of electrons making random motions, the aligned flow of these occurs under the influence of the electric force.

Example 2:

You might have heard of Coulomb’s law. The electric force between two mutual charges having the same magnitude but the opposite polarity is given by Coulomb’s law.

Example 3:

Let us wind a wire around the iron nail, and supply the current to it. We observe that on supplying the current,  the magnetic field generates around it. 

Do you know why it happens? It happens because a wire or the loop contains millions of electrons making random motions, so when current flows through the wire, these electrons align in the specified direction, and therefore, a magnetic field generates.