Newton And His 3 Laws Essay, Research Paper

Sir Isaac Newton

Sir Isaac Newton (1643-1727), was an English mathematician and physicist,

he is considered one of the greatest scientists in history, who made important

contributions to many fields of science. His discoveries and theories laid the

foundation for much of the progress in science since his time. Newton was one of the

inventors of the branch of mathematics called calculus (the other was German

mathematician Gottfried Wilhelm Leibniz). He also solved the mysteries of light and

optics, formulated the three laws of motion, and derived from them the law of

universal gravitation.

Newton was born on January 4, 1643, at Woolsthorpe, near Grantham in

Lincolnshire. When he was three years old, his widowed mother remarried, leaving

him in the care of his grandmother. Eventually his mother, by then widowed a

second time, was persuaded to send him to grammar school in Grantham. Later, in

the summer of 1661, he was sent to Trinity College, at the University of Cambridge.

Newton received his bachelor’s degree in 1665. After a break of nearly two

years to avoid the plague, Newton went back to Trinity, which elected him to a

fellowship in 1667. He received his master’s degree in 1668. Newton ignored much of

the established curriculum of the university to pursue his own interests:

mathematics and natural philosophy. Proceeding entirely on his own, he

investigated the latest developments in mathematics and the new natural philosophy

that treated nature as a complicated machine. Almost immediately, he made

fundamental discoveries that were instrumental in his career in science.

The Fluxional Method

Newton’s first achievement was in mathematics. He generalized the methods

that were being used to draw tangents to curves and to calculate the area swept by

curves, and he recognized that the two procedures were inverse operations. By

joining them in what he called the fluxional method, Newton developed in the

autumn of 1666 a kind of mathematics that is now known as calculus. Calculus was

a new and powerful method that carried modern mathematics above the level of

Greek geometry.

Although Newton was its inventor, he did not introduce calculus into

European mathematics. In 1675 Leibniz came up with the same method, which he

called differential calculus. Leibniz proceeded to publish his method and received

sole credit for its invention until Newton published a detailed exposition of his

fluxional method in 1704. Always fearful of publication and criticism, Newton kept

his discovery to himself. However, enough was known of his abilities to effect his

appointment in 1669 as Lucasian Professor of Mathematics at the University of

Cambridge.

Optics

Optics was another area of Newton’s early interests. In trying to explain how

colors occur, he arrived at the idea that sunlight is a blend of different rays each of

which represents a different color and that reflections and refractions cause colors

to appear by separating the blend into its components. Newton demonstrated his

theory of colors by passing a beam of sunlight through a type of prism, which split

the beam into separate colors.

In 1672 Newton sent a brief exposition of his theory of colors to the Royal

Society in London. Its appearance in the Royal Society’s Philosophical Transactions

led to a number of criticisms that confirmed his fear of publication, and he tried to

keep away from the publics eye as much as possible. He then continued his

Cambridge studies. In 1704, however, Newton published Opticks, which explained

his theories in detail.

The Principia

In August 1684 Newton’s was interrupted by a visit from Edmund Halley,

the British astronomer and mathematician, who discussed with Newton the problem

of orbital motion. Newton had also pursued the science of mechanics as an

undergraduate, and at that time he had already written some basic notions about

universal gravitation. As a result of Halley’s visit, Newton went back into to these

studies.

During the next two and a half years, Newton established the modern science

of dynamics by making his three laws of motion. Newton applied these laws to

Kepler’s laws of orbital motion written by the German astronomer Johannes Kepler

and came up with the law of universal gravitation. Newton is probably best known

for discovering universal gravitation, which explains that all bodies in space and on

earth are affected by the force called gravity. He published this theory in his book

“Philosophiae Naturalis Principia Mathematica” in 1687. This book marked a

turning point in the history of science, it also ensured that its author could never

regain his privacy.

The Principe’s appearance also involved Newton in an unpleasant episode

with the English philosopher and physicist Robert Hooke. In 1687 Hooke claimed

that Newton had stolen from him a central idea of the book. However, most

historians do not accept Hooke’s charge of plagiarism.

In the same year, 1687, Newton helped lead Cambridge’s resistance to the

efforts of King James II to make the university a Catholic institution. After the

English Revolution in 1688, which drove James from England, the university elected

Newton one of its representatives in a special ceremony of the country’s parliament.

The following four years were filled with intense activity for Newton by as he was

surprised by the success of the Principia, he tried to put all his earlier achievements

into a final written form. In the summer of 1693 Newton showed symptoms of a

severe emotional disorder. Although he regained his health, his creative period had

come to an end.

Newton’s connections with the leaders of the new regime in England led to

his appointment as warden, and later master, of the Royal Mint in London, where

he lived after 1696. In 1703 the Royal Society elected him president, an office he

held for the rest of his life. As president, he ordered the immediate publication of

the astronomical observations of the first Astronomer Royal of England, John

Flamsteed. Newton needed these observations to perfect his lunar theory. This

matter led to a big fight with Flamsteed.

Newton also engaged in a violent dispute with Leibniz over who was the

inventor of calculus. Newton used his position as president of the Royal Society to

have a committee of that body investigate the question, and he secretly wrote the

committee’s report, which charged Leibniz with deliberate plagiarism. Newton also

compiled the book of evidence that the society published. The effects of the fight

showed until his death in 1727.

In addition to science, Newton also showed an interest in alchemy, mysticism,

and theology. Many pages of his notes and writings particularly from the later years

of his career are devoted to these topics. However, historians have found little

connection between these interests and Newton’s scientific work.

Newton’s First Law of Motion

“An object in motion tends to stay in motion, and an object at rest tends to stay at rest, unless the object is acted upon by an outside force.”

This means that if you leave a book on your coffee table over night, when you

return in the morning, unless an outside force moved it, it will be in the same place.

This also means that if you kick a soccer ball, it will continue moving until it hits

something. However we all know the ball will eventually stop even if it does not hit a

wall – this is because of the friction between the ball and the ground, and between

the ball and the air.

We feel the effects of Newton’s First Law every day, but usually don’t notice

them because other forces interfere. In space, the First Law is much more obvious.

Objects will follow their natural trajectories until an outside force stops them. On

earth, the atmosphere will eventually slow down all moving objects, but in a vacuum

(basically an empty space with no air or atmosphere), like space, it will be more

obvious that objects obey Newton’s Laws.

One of the most common places people feel the First Law is in a fast moving

vehicle, such as a car or a bus, that comes to a stop. An outside force stops the

vehicle, but the passengers, who have been moving at a high speed, are not stopped

and continue to move at the same speed. Below is an example of this:

Newton’s Second Law of Motion

Newton’s Second Law is easily expressed by an equation:

Acceleration = Force/Mass

This is usually shortened to A=F/M or F=MA. Since acceleration is the rate

at which speed changes, it is usually expressed in units of m/s (every second, the

object that is accelerating will go that much faster). Force is usually expressed in

Newtons (N), which are kg/s.

Newton’s Second Law is more abstract than the First. The Second Law

governs all acceleration and is really very simple – acceleration is produced when a

force acts on a mass. The greater the mass (of the object being accelerated) the

greater the amount of force needed (to accelerate the object).

Everyone unconsciously knows the Second Law. Everyone knows that

heavier objects require more force to move the same distance than do lighter

objects. The Second Law, however, gives us an exact relationship between force,

mass, and acceleration. Below is an example of how Newton’s Second Law works:

Newton’s Third Law of Motion

Newton’s Third Law is probably his most famous. In short, it is:

“Every action has an equal and opposite reaction”

These actions are forces, so you can remember this law as being every force

has an equal and opposite force. Remember that these are two separate forces,

which act upon two separate objects, and so they do not cancel each other out.

The Third Law at first seems simple, but is a very important law. Every time

we interact with our surroundings we feel the Third Law. When you punch someone

in the face, your hand not only applies a force to the person’s face; the person’s face

applies a force to your hand. Since the person’s face is softer than your hand it

suffers more from the interaction. The Third Law is very important for space

travel. In the cold void of space there is no air for jets to suck or for propellers to

churn, and yet space ships can maneuver in a vacuum. How do they do it? The

engines propel gas particles out the back of the space ship. Since every force has an

equal and opposite reaction force, the space ship will be propelled forwards.

Because of the First Law, space ships do not need very much fuel – once they are

moving they will stay in motion

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