Sheila Gangopadhyay

Jan.28, 2002

EDSE 452/453 – Science Vignette: Sir Isaac Newton (1642-1727)

(Curricular Fit : Science 7 : Unit D – Structures & Forces, Science 8 : Unit D – Mechanical Systems,

Science 9 : Unit E – Space Exploration, Science 10 : Unit 4 – Change & Energy)

“Ouch!! Was that an apple that just fell on my head?! Oh man – that bump’s going to be huge!!” Thankfully for us, when Isaac Newton sat under a tree and had an apple fall on his head, his thoughts turned in a different direction – he came up with the idea of gravity…

Isaac Newton was born on Christmas day, 1642, in the small village of Woolsthorpe in Lincolnshire, England. His father, a yeoman, died a few months before Newton's birth, and his mother soon remarried, after which Newton was raised by his grandmother on the family farm. He was educated at Trinity College, Cambridge University, where he studied mathematics as applied to astrology. In 1665 and 1666, the plague hit England, so the university closed; Newton went home and spent most of his time on the family farm with his mother, again a widow. It is there in the family orchard that Newton had his “Eureka!” moment with the fallen apple, and thought of the idea of gravity.

He was sitting outside under the shade of a tree on a hot summer evening when an apple landed on his head. After the pain in his head cleared and he opened his eyes, he noticed the large Harvest Moon that evening. Having recently been pondering his calculus “fluxions”, he was struck by the thought that if the law of gravitation was the inverse square of the distance between two bodies of mass, it would be easy to check by the rate of fall of the moon towards the Earth compared to the rate of fall of an apple towards the Earth. With a few rough calculations, Newton was able to prove the universality of gravity.

Those years at home proved to be golden for Newton – he made advances in mathematics (binomial theorem, differential calculus – fluxions), optics (theory of colors, theory of light), and mechanics (gravity and the inverse square law, first two laws of motion). Although Newton did some publishing in his early years after returning to the university in 1669, he was involved in a fairly public dispute with Robert Hooke, then President of the Royal Society of London, who accused Newton of plagiarizing his inverse square law for gravitation. The dispute was never properly resolved, and as a consequence, Newton did not publish to any appreciable extent until after Hooke’s death.

In 1684, Edmund Halley encouraged Newton to publish his research on mechanics, but because Newton was so reluctant to have it printed, Halley later paid for its publication. In 1687, less than 2 years later, Mathematical Principles of Natural Philosophy (the “Principia”) was published; it was an instant success and revealed Newton's genius for original thinking on such things as planetary motion, lunar motion, and tides. He also published his three Laws of Motion; 1st Law of Motion: a body remains in its state of motion unless acted on by an external force – the property of inertia, 2nd Law of Motion: a body acted on by an external force will change its momentum in the direction of the force, such that the greater the force the greater the change in momentum, and 3rd Law of Motion: forces always occur in pairs, i.e., for every action there is an equal and opposite reaction.

Unfortunately, after that he suffered a nervous breakdown, which lasted about 5 years. He relocated to London, where in 1699 he was appointed Master of the Mint, and lead currency reform in England. He served in Parliament in 1689 and 1701, and in 1704, published Opticks. He was knighted in 1705, under the reign of William and Mary, and became President of the Royal Society, which he remained until his death in 1727. He was then buried in Westminster Abbey.

This colorful genius was a bit of a hypochondriac – he was always paranoid and fearful that other people would steal his ideas. In fact, very few models Newton made or used are still intact today, as he destroyed them almost as soon as he was done with them, so that no one else could steal his ideas. As a result, Newton never collaborated with any other scientists – all of Newton's achievements were solitary. In addition to his paranoia, Newton’s long-standing feud with Hooke continued even after Hooke’s death; after Newton became President of the Royal Society of London, he ordered all busts and portraits of Hooke destroyed! Newton also had a widely publicized dispute with Leibniz, a German mathematician, about his ideas for calculus. Leibniz claimed that he had come up with the ideas prior to Newton, whereas Newton claimed that Leibniz had plagiarized his ideas from notes of his that Leibniz may have inadvertently viewed. The majority of scientists at that time sided with Newton, but there is still some controversy over when and who came up with the ideas and proofs for differential calculus.

For that matter, while Newton’s Laws of Motion are still used in their original form today, Newton’s idea of gravity was such a departure from mechanical norms and scientific ideas of the day that even HE did not quite believe it. He still partly believed that some intervening medium (called ether) existed which transmitted gravitational pull in a mechanical fashion. That he, the one who originally came up with the new theory, still questioned his own theory of gravity in a vacuum, shows how firmly the human mind is committed to previous ideas, in this case mechanical models, and is unsatisfied when a purely mathematical argument is presented. However, after Newton’s death, the planets Neptune and Pluto were discovered, in 1846 and 1930 respectively, because of their gravitational influence on the planet Uranus, proving that Newton’s gravitational inverse square law really does work in a vacuum.

Therefore, even though Newton was an interesting character who could be charming one moment and spiteful and irascible the next, his contributions to scientific knowledge, both planned and serendipitous, cannot be doubted – many of his theories have withstood the test of time and are still being used in science and mathematics today.

Questions:

1) What role does politics play in the way that scientific theories and knowledge are presented and used by the scientific community and the public?

2) Even though science is supposed to be a collaborative activity, Newton never worked with colleagues in the scientific community when developing his ideas. Considering this, how can scientists feel free to share their unpublished work with colleagues without worrying about another scientist “stealing” their ideas?

3) How much effect does sudden inspiration and luck have on scientific discoveries, compared to steady and methodical scientific experimentation and thought?

4) How could a scientists like Newton, who didn’t even quite believe his own theory of gravity existing in a vacuum, convince others to make such a great leap of change in their thinking?

References

Andrade, E.N. da C.1954. Sir Isaac Newton. Doubleday &Company, Inc. New York, USA.

Brodetsky, Selig. 1927. Sir Isaac Newton: a brief account of his life and work. Methuen & Co., Ltd., London, UK.

De Morgan, Augustus. 1914. Essays on the life and work of Newton. The Open Court Publishing Company, London, UK.

Dimitric, R. 1991. Isaac Newton. Mathematic Intelligencer 13 (1): 61-65

Evans, J.C. 1995. Physics & Astronomy Department, George Mason University, USA.

http://www.physics.gmu.edu/classinfo/astr228/CourseNotes/ln_ch12.htm

McMullin, Ernan. 2001. The Impact of Newton's 'Principia' on the Philosophy of Science. Philosophy of Science 68 (3): 84-87

Palter, Robert. 1970. The Annus Mirabilis of Sir Isaac Newton 1666-1966. The MIT Press, Cambridge, USA.

Shea, W.R. 1993. The Life of Isaac Newton. Nature 364 (6439): 681-682.

Villamil, Richard de.1972. Newton: the man. Johnson Reprint Corporation, New York, USA.

http://www.geocities.com/CapeCanaveral/Lab/3550/newtonzi.htm

http://scienceworld.wolfram.com/biography/Newton.html