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
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
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
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.
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
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