In our daily life we enjoy by watching TV, films, circus, using cell phones, internet etc. Did you ever think of physics is behind them?

What is Physics?

In Greek, physics means "nature". It deals with the study of basic laws of nature and they are applied widely in different contexts and conditions. Physics and technology correlated. Sometimes technology gives rise to new physics, at other times physics generates new technology. Physics has two domains, microscopic and macroscopic. Microscopic domain called Quantum physics deals with the constitution and structure of matter at minute scales of atoms, nuclei and their interaction with electrons, photons and other elementary particles. Macroscopic domain called classical physics, deals with Mechanics, Electrodynamics, Optics, and Thermodynamics.

Fundamental forces in nature:

Microscopic and macroscopic phenomenon can be explained on the basis of fundamental forces. There are four fundamental forces in nature. They are

(i) Gravitational

(ii) Electromagnetic

(iii) Strong Nuclear

(iv) Weak nuclear forces.

Gravitational Force:

It is the mutual force of attraction between any two objects by virtue of their masses. It is a universal and a long range force. The formation and evolution of stars, galaxies is explained on the basis of gravity.

Electromagnetic force:

It is the force between charged particles (may be attractive or repulsive). It is a long range force, stronger than gravity.}

Nature of physical laws:

Physicists explore the universe.

Strong nuclear forces:

These are forces which binds protons and neutrons in nucleus, strongest among all fundamental forces.

Weak nuclear forces:

These nuclear forces appear in β - decay.

In their discovery, they observed that few physical quantities remain constant with time called conservative quantities (mass, energy, linear momentum, angular momentum and charge). Conservation laws are true for one fundamental force not for others. These laws have connection with symmetry of nature, space and time. Symmetry play a role in modern theories, fundamental forces in nature. For example law of gravitation is same every where in the universe i.e., it has symmetry in nature. But acceleration due to gravity is different from place to place i.e., it does not have nature of symmetry.