Nature Of Light Newton example essay topic

Isaac Newton Newton was born on the 25th December 1642 and died in 1727. He was born In Wools thorpe in Lincolnshire. His father was a farmer but he died Three months before Newton was born. His mother remarried and Newton spent his childhood with his grandmother.

At school he showed great skill in making model kites, sundials and windmills. In 1665 when he was 18 he went to study mathematics at Cambridge University. He continued his studies at home when the University closed because of the plague. The Reflecting Telescope Because Newton was working with light in 1668 he made the first reflecting telescope. The light was collected and reflected from a curved mirror instead of being refracted through a lens. It was far superior from the refracting telescopes at that time because it reflected all the light in the same way.

It did not produce colour fringing or blurring which occurred in the early refracting telescopes. The Nature of Light Newton discovered the nature of light when he darkened his room and "made a small hole in my shuts to let in a convenient quantity of the sun's light". He passed this beam of sunlight through a prism. When the light came out of the prism is was not white but was of seven different colours: Red, Orange, Yellow, Green, Blue, Indigo and Violet. The spreading into rays was called DISPERSION by Newton and he called the different coloured rays the SPECTRUM. He learnt that when the light rays were passed again through a prism the rays turned back into white light.

If only one ray was passed through the prism it would come out the same colour as it went in. Newton concluded that white light was made up of seven different coloured rays. The rays were dispersed through the prism because the rays were reflected at different angles. Newton wondered whether the different colours of the spectrum travelled at different speeds. He wrote to Flamstead to ask if when he observed an eclipse whether the colour changed all at once of at different times. Flamstead wrote back to him to say that the colours changed all at once.

The Calculus Newton invented the Calculus branch of mathematics around 1669. He did not publish his ideas until around 1704, 35 years later. This branch of mathematics is divided into two parts: Differential Calculus Integral Calculus Differential Calculus Differential Calculus deals with the rates things change at. When a car moves off from a halt the distance changes slowly at first.

When the speed increases the distance changes quicker. As shown in the graph below: What really happens is shown below: The car accelerates quickly at first. The acceleration drops as the car changes gear. The acceleration is zero when the car reaches a cruising speed. Differential Calculus is used to calculate the orbits of planets and satellites very exactly. Integral Calculus Integral calculus is used for measuring quantities by dividing them into many small parts.

An example is the area of a circle. The circle is divided into sectors. As the number of sectors increases the size of the sectors get smaller. The sectors are arranged into a rectangle: As the sectors shrink to almost nothing, the shape is almost a rectangle.

The height of the rectangle is almost equal to R (Radius) and the width is C (Circumference), as the circumference is spread between the bottom and top of the rectangle. The area of the rectangle is R x C. As C = 2 pR the area of the rectangle is R x 2 pR or pR 2. The books Newton wrote Newton's most famous book was called "Philosophe Naturalis Principia Mathematica" It was published in 1678 and was known as "Principia". The book contains all his laws of motion and theories of tides and gravitation.

He also wrote another book, "Optics", which was published in 1704 and describes the Calculus and other mathematics. It also describes his theory of light. Motion and Gravity In 1670 Newton worked more on chemistry and alchemy than on optics and mathematics. It is said that Newton wondered why objects fell to earth when he was sitting in a garden and saw an apple drop in front of him. This is still believed by some people although many people think it is untrue.

Newton thought back to the subject which he was thinking about in 1665-66. This was "Why things move as they do". He made three laws of motion: First Law of Motion A body continues in a state of rest or to move with a steady velocity in a straight line if it is not acted upon by forces. If a ball is kicked in outer space it will continue to move at the same speed as no forces act upon it, such as friction and air resistance.

If a ball is kicked on earth it will slowly come to halt on the ground as friction, air resistance and gravity have acted upon it. Second Law of Motion When a force acts on body it produces an acceleration which is proportional to the magnitude of the force. If a ball is kicked its acceleration is related to the power of the kick and the mass of the ball. The ball also moves in the direction of the force. Therefore a small, light ball travels faster than a big, heavy ball.