Cosmos [08] Newton's Laws of Motion

© ABCC Australia 2015 www.new-physics.com

Cosmos: Part 8

Nature and nature’s law hid in night;

God said “Let Newton be” and all was light.

Alexander Pope

NEWTON’S PRINCIPIA


Sir Isaac Newton

Sir Isaac Newton (1642 – 1727) was an English physicist and mathematician (described in his own day as a "natural philosopher") who is widely recognised as one of the most influential scientists of all time and as a key figure in the scientific revolution. His discovery of the law of gravity and the laws in mechanics laid the foundations for classical mechanics. He also made seminal contributions to optics, and he shares credit with Gottfried Leibniz for the development of calculus. Wikipedia.


Principia Mathematica

The most important document in the field of physics was published in 1686 by Sir Isaac Newton through the Royal Society in his book entitled:

“Philosophiae NaturalisPrincipia Mathematica”

Which in modern day English is:

“The Mathematical Principles of Natural Science”.

Since then the kinetic behavior of a particle is completely and satisfactorily describable by his three basic theorems.

Title page of the first edition of the Principia.


On the Shoulders of Giants

The Principia has long been recognized as one of the intellectual landmarks in the history of physics. It is the first book to show clearly the close relationship between mathematics and formal logic. . . . No other book has such an influence on the subsequent history of mathematical philosophy. A. N. Whitehead and Bertrand Russell: Principia Mathematica. Cambridge University Press. 1910.

Newton was rather modest with his own achievements. In his letter to Robert Hooke in February 1676, he wrote:

If I have seen further it is by standing on the shoulders of giants.


3 LAWS OF MOTIONNewton’s

IIIIII


Newton’s Three Laws of motion

In forms slightly different from the original versions, Newton’s laws of motion can be stated as follows:

Law No. ❶ :

A particle in rest will remain forever at rest, and a particle in uniform rectilinear motion will continue to move on forever at constant speed in the same direction. It will change its state of motion only and only when it is compelled to do so by forces impressed on it.


Newton’s 2nd Law of motion

When a particle is acted on by an external force, it accelerates. The acceleration is proportional to the magnitude of the applied force 𝑭𝑭 and is in the same direction as the applied force. If the particle has a mass of 𝑚𝑚and the applied force is represented by the vector 𝐹𝐹, then:

𝑭𝑭 = 𝑚𝑚𝒂𝒂


Newton’s Third Law of motion

Whenever one body exerts a force F onto a second body, the second body exerts the force −Fon the first body. 𝑭𝑭 and −F are equal in magnitude and opposite in sense.

|𝑭𝑭| = | − 𝑭𝑭|


Simple laws & universal application

We now have established that in nature, there are different properties pertaining to motion: velocity, force, impetus and inertia.

By setting up the Laws of Mechanics, Newton established the relationship between the various elements. He also showed that the same physical laws are universal and can be applied to all matter, whether living or nonliving, on earth or in space, thus revolutionizing our view of the universe.

𝑭𝑭 = 𝑚𝑚𝒂𝒂

|𝑭𝑭| = | − 𝑭𝑭|


Foundation of Classical Mechanics

This is the first time in history that the kinetic behavior of a particle is completely and satisfactorily describable by the three theorems. Since Newton’s time these theorems were accredited with the status of laws and had become the very foundation of classical mechanics.


The Nature of Momentum and Force

Although Newton provided us with the rules to calculate momenta and forces, he did not give an explanation to their nature. Nobody had been successfully found a solution so far even in this modern age.

Our articles on Phonons are to explain what momentum and force really are and how the answers also unveil to us the existence of a new fundamental force in addition to the existence 4 forces in nature.

Articles on the cause of motion already published in the website: new-physics.com:

Part 1. World in motion

Part 2. Cartes to Newton

Part 3. Newton's Principia

Part 4. Newton & Kung Fu

Part 5. Conclusion – Phonons

Example: de Broglie’s matter waves in 3 parts.


If we want to proceed further to Newton’s theory of gravitation, we have to meet with a diversion.

CONTACT FORCE

ACTION-AT-A-DISTANCE FORCE


Two different kinds of force

Mechanical force is a contact force. Gravitation is an action-at-a-distance (AAAD) force.

They are of different kind and need to be treated separately.

We have dealt with contact force in our search for its source which ended up with the phonon.

For gravitation we shall study it together with electricity and magnetism which also act at a distance.

Action without contact

Action with contact


To be continued in: Action-at-a-distance forces: Gravitation, electricity and magnetism.

Cosmos [08] Newton's Laws of Motion

Science

Transcript of Cosmos [08] Newton's Laws of Motion