Physics: A Brief Introduction

Science is a systematic, intellectual, and practical strive to study the natural phenomena through in-depth observation and experimentation aimed at predicting, modifying, and/or controlling the phenomena. It is derived from the Latin word 'Scientia' meaning 'to know'. Physics is a branch of natural science dealing with the study of basic laws of nature and their manifestation in different natural forms. In simple words, the ultimate goal of physics is to understand how the universe behaves. The scope of physics is truly very vast as it envelops an enormous range of magnitude of length (less than 10^[-4] m to 10^[26] m), time (10^[-22] s to 10^[18] s), mass (10^[-30] kg to 10^[55] kg), etc. 

Unification and Reductionism are the two main drives in physics. Unification aims at the applicability of some fundamental laws to a broad range of phenomena like Newton's Law of Gravitation explaining the fall of any object to the ground and motion of planets around the sun. Reductionism refers to the derivation of properties of the complex and bigger system from its constituents and simpler parts.

We've already seen the vastness of the scope of physics. Depending on the length scale we can divide the entire domain of the physical world into two parts: microscopic and macroscopic. The macroscopic world is mainly dealt with by Classical physics, whereas Quantum physics handles the microscopic part. Below table describes the sub-disciplines of physics and their basic definition:

Sub-Disciplines		Basic Definition
Classical Physics	Mechanics	Deals with the study of motion and forces (Newton’s laws of motion & the law of gravitation)
	Electrodynamics	Deals with the study of electric and magnetic fields
	Optics	Deals with the behavior and properties of light
	Thermodynamics	Deals with the study of relations between various forms of energies like heat, work, etc.
Quantum Physics		Deals with the study of microscopic phenomena

Having discussed the sub-domains of physics, let us shift our attention towards the forces. There are a host of forces present in different contexts, but they all can be divided under four fundamental forces in nature:

	Gravitational Force	Electromagnetic Force	Strong Nuclear Force	Weak Nuclear Force
Definition	Force occurring due to virtue of mass	The force between the charged particle	The force which binds protons and neutrons in the nucleus	Occur only in the certain nuclear process
Sign	Always attractive	Attractive or repulsive	-	-
Range	Infinite	Infinite	Small (10^[-15] m)	Very Small (10^[-16] m)
Relative Strength	10^[-39]	10^[-2]	1	10^[-13]

Before wrapping up this article let us look at some of the notable contributions from the great minds of physics:

Name	Major Contribution
Issac Newton	Law of gravitation; Laws of motion; Law of cooling
Albert Einstein	Theory of relativity
Archimedes	Buoyancy principle
Michael Faraday	Laws of electromagnetic induction
Galileo Galilei	Law of inertia
J.C. Maxwell	Electromagnetic Theory
J.J. Thomson	Discovery of electron
James Chadwick	Discovery of neutron
Neils Bohr	Quantum model of the hydrogen atom
Ernest Rutherford	Nuclear model of the atom
Wolfgang Pauli	Exclusion Principle
Werner Heisenberg	Uncertainty Principle