Classical Mechanics-Physics

The foundation of classical physics is laid by the then scientist Isaac Newton (1642-1727). It’s actually the Newtonian mechanics but in order to distinguish Newtonian mechanics from relativistic and quantum mechanics (a modern physics), it is commonly referred to as classical mechanics. It is the basis of modern physics.

Mechanics is the study of the relationship among matter, motion, and cause(s) of motion. More correctly, cause(s) of the change in motion of objects.

There are two major subdivisions of mechanics:

i) Kinematics: Kinematics is the study of motion ignoring its causes.

ii) Dynamics: Dynamics is the study of the relationship of motion to its causes.

Before Newton and Galileo, Physics relied on natural philosophy-the philosophical study of nature and the physical universe. The natural philosophy relied on observations of nature and pure reason to explain those observations. Most explanations were qualitative and only applicable to a specific “kind” of object or “kind of matter”. Further, explanations were not required to be testable or make predictions; they are “self-evident”.

The science of Physics is essentially begin with the time of  Galileo Galilei(1564-1642).

Galileo insisted on experimental observations supported by careful measurements to validate the claim about nature. This is the core of scientific method. It is not enough to think something is true, you must be able to demonstrate, it is true with empirical evidence.

Newtonian mechanics is a theory of mechanics based on Newton’s three laws of motion and law of universal gravitation and that apply to macroscopic objects moving at speeds much less than the speed of light. The mathematical equations given by Newton are the fundamental equations and cannot be derivable.

Classical Newtonian mechanics is a theory that explains the relationship among force, matter and motion and that the theory is based on Newton’s three laws of motion which applied to object much larger than atoms and the speed much less than the speed of light and for this reason I like to think that classical mechanics as the mechanics of naked eye because we can see the object much larger than the atoms and the object are moving much less than the speed of light.

Newton was born in the same year that the Galileo died(1564-1642) and given the Newton’s mathematical principles of Natural Philosophy (1687).His monumental works generally referred to the Principia contains i) Newton’s three laws of motions, ii) Newton’s law of Universal Gravitation, iii) Derivation of kepler’s laws of planetary motion

In particular, Newton law of motion and law of universal gravitation applies to all (macroscopic objects), terrestrial and celestial. The natural state of terrestrial object is to be at rest upon the earth. The natural state of celestial object is to be in constant circular motion about the earth.

Newton proclaimed, the force falling the apple to the ground and the force keeping the moon in orbit around the earth was actually is the same. Newton unified the heaven and the earth in a single theory he called the gravity. The unification of celestial with terrestrial was the fantastic unification of picture of nature.

A law states a direct relationship between two or more physical quantities that can be observed and measured. A law does not explain why this relationship is observed. In science, a theory is a explanatory and predictive model of a natural phenomenon that is tested and confirmed through observation and experimentation. So, a theory explains observations, including empirical laws, and makes predictions about future observations. Newton called the observable phenomenon that physical bodies with mass attract one another gravity.

In physics, a force is an interaction that can change the motion of an object (either its speed or direction of motion).The force of gravity is the gravitational interaction between objects with mass that can change the motion of one or all of the objects. Newton law of universal gravitation is an empirical statement regarding the strength (magnitude) of the force of gravity.