I know, I know, I’m way behind on my A to Z posts. Life hit me hard this month but I’m doing my best to start catching up. I plan to post for two letters a day until I’m back on track. Thank you for reading :)
Just about every one has heard of Sir Isaac Newton, the English physicist and mathematician, “natural philosopher”, and one of the great minds of the 17th century Scientific Revolution. He is widely regarded as one of the most influential scientists of all time and best known for his work in formulating the laws of motion and universal gravitation, which dominated scientists’ view of the physical universe for the next three centuries.
Newton is also credited with removing the last doubts about the validity of the heliocentric model of the Solar System. He even helped invent calculus, simultaneously, yet separately, from Gottfried Leibniz. I can’t even understand calculus and this guy invented it! He did a whole lot more too and for the life of me I cannot understand where he found the time, energy, and pure genius to do so much in one short human life-span. He is one of my favorite scientists and no talk of astronomy would be complete without some mention of his name.
Just about everyone has also heard of Newton’s laws of motion, which were derived from Johannes Kepler’s Laws of Planetary Motion and his own mathematical description of gravity as well.
- An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
- A force causes a change in the velocity (acceleration) of an object (F=ma). Or, the greater the mass of the object, the greater the force required to accelerate it.
- For every action there is an equal and opposite reaction.
Newton, born Christmas day 1642, in county of Lincolnshire, England. He was born three months after his father’s deatch and he was premature. His mother said he was so small “he could have fit inside a quart mug”. At the age of three his mother went to live with her new husband and left him in the care of his grandmother. From his own accounts he hated his step-father and resented his mother for marrying him. In a list of sins committed up to the age of 19 he wrote: “Threatening my father and mother Smith to burn them and the house over them”.
His step-father later died and Newton’s mother tried her best to turn him into a farmer but Newton hated farming. He went back to school and motivated partly by a desire for revenge against a schoolyard bully, he became the top-ranked student.
In June 1661, he was admitted to Trinity College, Cambridge where he studied philosophy and astronomy. He was wasn’t a particularly remarkable student but was influenced by the philosophers Aristotle and Descartes, and the astronomers Galileo, Thomas Street, and Kepler and started writing a series of questions in his notebook pertaining to mechanical philosophy and developed a mathematical theory that would later become calculus.
In August of 1665, the university had to close its doors against the Great Plague and Newton studied at home. This is where he really began to do his serious work. Over the next two years he developed his theory of calculus, optics, and gravitation.
When he returned to Cambridge he was elected as a fellow of Trinity. Fellows were required to become ordained priests, but Newton managed to avoid it with a special permission from Charles II.
Newton’s most famous book, Philosophiæ Naturalis Principia Mathematica (“Mathematical Principles of Natural Philosophy”), first published in 1687, laid the foundations for classical mechanics, and is regarded as one of the most influential in the field of physics.
In it Newton states that every point mass attracts every single other point mass by a force pointing along the line intersecting both point. According to his calculations, this force is proportional to the product of the two masses and inversely proportional to the square of the distance between them. Newton would go on to use these principles to account for the trajectories of comets, the tides, the procession of the equinoxes, and other astrophysical phenomena.
His work also demonstrated that the motion of objects on Earth and of celestial bodies could be described by the same principles.
Throughout his life Newton’s work is said “to distinctly advance every branch of mathematics then studied”. It can be argued that Newton was the greatest genius who ever lived. The poet Alexander Pope was so moved by Newton’s accomplishments to write the famous epitaph:
Nature and nature’s laws lay hid in night;
God said “Let Newton be” and all was light.
Newton himself , being a bit more modest, famously wrote in a letter to Robert Hooke:
If I have seen further it is by standing on the shoulders of giants.
and later in his memoir:
I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
He was a great but also flawed. It is said that he had a horrible temper and hated to hear any criticism of his work. He often feuded with other mathematicians, particularly with Leibniz over priority in the development of calculus. Newton was also deeply introverted and quite protective of his privacy. He is said to have been quite insecure. He suffered psychological problems and insomnia which culminated into a nervous breakdown in mid-1693, when, after five nights of sleeping ‘not a wink’, he temporarily lost all grip on reality and became paranoid of his colleagues.
Despite all that though no one can deny his immense contribution to science and mathematics. In old age he was a famous man who had amassed a large collection of awards and wealth and his scientific discoveries were unchallenged. He never married or made many friends, what few he had worried about his mental stability.
Around the age of 80 Newton began experiencing digestion problems. He was forced to drastically change his diet and mobility. Then, in March 1727, Newton experienced severe pain in his abdomen and blacked out. He would never regain consciousness. He died the next day, on March 31, 1727, at the age of 85.
Image: This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera. The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach in August 1989. The picture shows the Great Dark Spot and its companion bright smudge; on the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds were seen to persist for as long as Voyager’s cameras could resolve them. North of these, a bright cloud band similar to the south polar streak may be seen.
By NASA (JPL image) [Public domain], via Wikimedia Commons