The weakest of all fundamental forces is the gravitational force.

- Gravitational Force:
The gravitational force is the force of attraction between two objects with mass. It is responsible for keeping planets in orbit around the sun, holding galaxies together, and determining the weight of an object on Earth.

- Electromagnetic Force:
The electromagnetic force is responsible for the interaction between charged particles. It includes both electric and magnetic forces. This force is much stronger than the gravitational force and is responsible for holding atoms and molecules together, as well as causing interactions between charged particles.

- Weak Nuclear Force:
The weak nuclear force is responsible for certain types of radioactive decay. It is involved in processes such as beta decay, where a neutron can change into a proton or vice versa. While it is stronger than the gravitational force, it is still weaker than the electromagnetic force.

- Strong Nuclear Force:
The strong nuclear force is the strongest of all fundamental forces. It is responsible for holding the nucleus of an atom together. This force overcomes the electromagnetic repulsion between protons in the nucleus and binds them together.

The reason why the gravitational force is considered the weakest of all forces is due to its incredibly small strength compared to the other forces. The gravitational force is about 10^38 times weaker than the electromagnetic force and about 10^36 times weaker than the weak nuclear force.

This weakness of gravity can be observed in everyday life. For example, when you pick up an object, the electromagnetic force between the atoms in your hand and the object overpowers the gravitational force, allowing you to lift it easily. Similarly, the electromagnetic force between Earth and objects on its surface is much stronger than the gravitational force, which is why objects don't simply float away into space.

In the realm of particle physics, the weakness of gravity becomes even more pronounced. At the quantum level, the gravitational force is not well understood and is not yet successfully unified with the other fundamental forces. This is known as the problem of quantum gravity.