Category Great Scientist

How did Newton’s experiments prove the components of white light?

Newton’s discoveries revolutionized our understanding of the most common aspects of nature such as light. Prisms were seen as trivial toys used for fun in laboratories until Newton came across them. He conducted a series of experiments with sunlight and prisms after getting a prism at a fair in 1664.

Newton made the astonishing discovery that clear white light was composed of seven visible colours. The visible spectrum, the seven colours of the rainbow, was scientifically established by Newton. This discovery opened new vistas in optics, physics, chemistry, and the study of the colours in nature.

One bright sunny day, Newton darkened his room and made a hole in his window shutter, allowing just one beam of sunlight to enter the room. He then took a glass prism and placed it in the sunbeam. The result was a spectacular multi-coloured band of light just like a rainbow.

Newton believed that all the colours he saw were in the sunlight shining into his room. He thought he then should be able to combine the colours of the spectrum and make the light white again. To test this, he placed another prism upside-down in front of the first prism. He was right. The band of colours combined again into white sunlight. Newton was the first to prove that white light is made up of all the colours that we can see.

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Why is Isaac Newton considered to be one among the greatest mathematicians?

We may remember Newton mostly in association with the theory of gravity and the story of the apple tree. But he was also a great mathematician on par with legendary figures like Archimedes and Gauss. Newton’s contributions paved the path for numerous mathematical developments in the succeeding years.

Until Newton, algebraic problems where the answer was not a whole number posed a problem for mathematicians. The formula published by Newton in 1676 called ‘binomial theorem’ effectively resolved this issue. It has been said that through Newton’s works, there was remarkable advancement in every branch of mathematics at the time.

Newton (along with mathematician Gottfried Wilhelm von Leibniz) is credited with developing the essential theories of calculus. He developed the theory of calculus upon the earlier works by British mathematicians John Wallis and Isaac Barrow, and prominent mathematicians Rene Descartes, Pierre de Fermat, Bonaventura Cavalieri, Johann van Waveren Hudde and Gilles Personne de Roberval.

While Greek geometry was static, calculus allowed mathematicians and engineers to make sense of the dynamic world around them. They could now make sense of motion such as the orbits of planets and the flow of fluids.

Many modern historians believe calculus was developed independently by Newton and Leibniz, using different mathematical notations. Leibniz was however, the first to publish his results.

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Why the year Newton spent in his home during the Great Plague is called his ‘year of wonders’?

With the outbreak of the bubonic plague, Cambridge University closed its doors in 1665. As a result, Newton was forced to return home to Woolsthorpe Manor where he ended up staying with his mother for over a year. In the peaceful countryside, he concentrated on the scientific problems about which he had wondered during his post graduate years.

Some of his greatest discoveries such as the laws of gravity, laws of motion, and the components of white light had their origin during this time.

It is said that Newton was sitting in the orchard when he saw an apple falling from a tree. Contrary to popular versions of this event, there is no evidence to suggest that the apple had fallen on his head. Pondering upon what he saw, Newton wondered why apples fall straight to the ground rather than going upwards or sideways. Following this line of thought, he finally formulated the law of universal gravitation.

This was the account of his discovery given by Newton himself to his acquaintances including the French philosopher Voltaire; his assistant at the Royal Mint, John Conduitt who was the husband of his niece Catherine Barton; his friend William Stewkeley; and Christopher Dawson who was a student at Cambridge. The note on Newton’s life collected by John Conduitt in 1726 contains the first written account.

The year he spent in Woolsthorpe later came to be called his annus mirabilis (year of wonders). Newton returned to Cambridge in 1667.

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What is the life story of Stephen Hawking?

The genius in the wheelchair

When Stephen Hawking was 21, he was given only a few years to live after being diagnosed with a rare form of motor neurone disease. Undaunted, Hawking made breakthroughs in quantum physics and cosmology with his “The Theory of Everything” and his work on black holes. Although a number of biographies have been written about the genius, a new memoir gives an affectionate account of Hawking and his indomitable spirit.

Written by Leonard Mlodinow, who worked closely with Hawking for nearly 11 years and co-authored two bestselling books with him (“A Briefer History of Time” and “The Grand Design”), “Stephen Hawking – A Memoir of Physics and Friendship gives fresh insights into Hawking’s character and his famous sense of adventure and fun.

A daredevil

Hawking was born on January 8, 1942 in Oxford. At 17, he won a scholarship to study at University College, Oxford. Despite his brilliance in academics, Hawking hated studying. According to his own estimates, he studied for only 1,000 hours during his three undergraduate years at Oxford. Once he even joined the college boat dub. But earned himself a daredevil reputation as he steered his crew on risky courses that often damaged boats.

Living with a rare disease

After being diagnosed with a rare form of motor neurone disease known as ALS, Hawking sunk into depression. Though the disease progressed slowly, it began to interfere with his daily activities, and his condition worsened in 1985 during a trip to Cern. Hawking underwent a tracheotomy, which saved his life but destroyed his voice. He started using a voice synthesiser.

The early diagnosis of the terminal disease ignited a sense of purpose in Hawking and he embarked on his career in earnest. He pursued his work with black holes and relativity with new zest. In 1988, Hawking published “A Brief History of Time, which turned him into an instant icon.

Writing for children

Hawking and his daughter Lucy came up with a series of illustrated books to explain the “secret keys to the universe” to young readers. The books deal with complex topics, including the Big Bang, black holes, atoms. planets and their moons, in the form of space adventures embarked on by junior astronaut George and his best friend Annie. The series helped simplify cosmology for children.

Love for adventures

Hawking enjoyed his fame, taking many opportunities to travel and to have unusual experiences such as going down a mine shaft visiting the south pole and undergoing the zero-gravity of free fall, and to meet other distinguished people.

Legacy

Hawking died at his home in Cambridge on March 14, 2018, at the age of 76. In the same year in June, Hawking’s words, set to music by Greek composer Vangelis, were beamed into space from a European Space Agency satellite dish in Spain with the aim of reaching the nearest black hole 1A 0620-00.

 

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WHO WAS THE FIRST PHOTOGRAPHER?

The first person to take a photograph was a Frenchman, Joseph Nicephore Niepce, in 1822. However, as is often the case with new inventions, many other scientists had been experimenting with light, lenses and light-sensitive chemicals. Working with Niepce was a man called Louis Daguerre, who later improved on Niepce’s process. Some early photographs were called daguerreotypes.

Around 1717 Johann Heinrich Schulze captured cut-out letters on a bottle of light-sensitive slurry, but he apparently never thought of making the results durable. Around 1800 Thomas Wedgwood made the first reliably documented, although unsuccessful attempt at capturing camera images in permanent form. His experiments did produce detailed photograms, but Wedgwood and his associate Humphry Davy found no way to fix these images.

In the mid-1822s, Nicephore Niepce first managed to fix an image that was captured with a camera, but at least eight hours or even several days of exposure in the camera were required and the earliest results were very crude. Niépce’s associate Louis Daguerre went on to develop the daguerreotype process, the first publicly announced and commercially viable photographic process. The daguerreotype required only minutes of exposure in the camera, and produced clear, finely detailed results. The details were introduced to the world in 1839, a date generally accepted as the birth year of practical photography. The metal-based daguerreotype process soon had some competition from the paper-based calotype negative and salt print processes invented by William Henry Fox Talbot and demonstrated in 1839 soon after news about the daguerreotype reached Talbot. Subsequent innovations made photography easier and more versatile. New materials reduced the required camera exposure time from minutes to seconds, and eventually to a small fraction of a second; new photographic media were more economical, sensitive or convenient. Since the 1850s, the collodion process with its glass-based photographic plates combined the high quality known from the Daguerreotype with the multiple print options known from the calotype and was commonly used for decades. Roll films popularized casual use by amateurs. In the mid-20th century, developments made it possible for amateurs to take pictures in natural color as well as in black-and-white.

The commercial introduction of computer-based electronic digital cameras in the 1990s soon revolutionized photography. During the first decade of the 21st century, traditional film-based photochemical methods were increasingly marginalized as the practical advantages of the new technology became widely appreciated and the image quality of moderately priced digital cameras was continually improved. Especially since cameras became a standard feature on smartphones, taking pictures (and instantly publishing them online) has become a ubiquitous everyday practice around the world.

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WHO DISCOVERED GRAVITY?

The fact that objects dropped from a height fall to the ground, that the Moon is near enough to be seen from Earth, and that we do not float into the air when we are standing still has, of course, been known for thousands of years. What was not known was the reason for these phenomena. It was a British scientist, Isaac Newton, who, in 1666, put forward the idea that the same force — gravity — might be responsible for all these events. Gravity is a force of attraction caused by the huge mass of the Earth.

Four fundamental forces govern all interactions within the Universe. They are weak nuclear forces, strong nuclear forces, electromagnetism, and gravity. Of these, gravity is perhaps the most mysterious. While it has been understood for some time how this law of physics operates on the macro-scale – governing our Solar System, galaxies, and superclusters – how it interacts with the three other fundamental forces remains a mystery.

Naturally, human beings have had a basic understanding of this force since time immemorial. And when it comes to our modern understanding of gravity, credit is owed to one man who deciphered its properties and how it governs all things great and small – Sir Isaac Newton. Thanks to this 17th century English physicist and mathematician, our understanding of the Universe and the laws that govern it would forever be changed.

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