Sir Isaac Newton was one of the most influential scientists of his time. He introduced many theories which are useful in our daily life. He is best known for defining gravity and three laws of motion. Newton’s most important work Philosophiae Naturalis Principia Mathematica got published in 1687. In this, he described both of his major theories. Sir Isaac Newton is also known as the father of modern physics.

**Discoveries of Sir Isaac Newton: –**

**Gravity: –**It is the most famous discovery by Isaac Newton. He outlined this theory in the Principia. His concept of gravitational force also helped in explaining the movements of the planets and the Sun.**Calculus: –**He invented a completely different type of mathematics. He named this new mathematics ‘fluxions’. Today, it is known as calculus. This type of mathematics is used in advanced engineering and science.**Reflecting Telescope: –**Newton invented the reflecting telescope in 1668. This telescope uses mirrors that reflect light and form an image. These reflecting telescopes are being used in the field of astronomy.**Laws of Motion:****–**He introduced three fundamental laws of physics. These laws laid the foundation of classical mechanics. Those three laws are: – Law of Inertia, Laws of Action and Reaction and the third law stated that acceleration proportional to force.**Rules for Scientific Reasoning:****–**He introduced a scientific methodology as a set of four rules for scientific reasoning. By applying these four universal rules, Newton formulated the universal law of nature.**Newton’s Rings:****–**In 1717, Newton observed an interference pattern caused by the reflection of light between two surfaces, a spherical and an adjacent flat surface. This pattern is circular in shape and known as Newton’s Rings.**The Philosopher’s Stone: –**It was a man-made stone or elixir. It was capable of changing any material from one state to another. It could turn lead into gold. This stone was also used to cure illnesses.