Page 2 of 2

The perspectives and contributions of Copernicus, Kepler and Galileo, were all inherited by Isaac Newton, who on July 5, 1687 published what some still consider to be the greatest work defining modern science – The Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy). Within this three volume work, Newton defines his Laws of Motion and the Law of Universal Gravitation, in the process he develops a new type of mathematical technique called Calculus.

After the publication of the Principia Mathematica, in which he described the action of gravity on objects, Newton came under pressure to provide an explanation for the causes of this gravitational effect. This caused problems for Newton; while he could describe and explain the motion of most objects, such as how billiard balls on a table are affected by their mass, velocity, friction, angle of intersection and so on, it was always fairly clear in these examples what type of force was producing the observable state of the balls. However, with gravity, while Newton’s mathematical law could describe and predict with great accuracy how an object would behave, such as the orbits of planets, the explanation of what force acted on the planets to cause this motion was unknown

Newton, however, did respond to these demands for an explanation of the nature of the gravitational force – and this is where the title for this article, in latin, is taken. Hypotheses non fingo: I feign no hypotheses.

"I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not feign hypotheses. For whatever is not deduced from the phenomena must be called a hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy. In this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction."

Newton, given an opportunity to speculate in public, or to attribute divine or metaphysical qualities to the nature of the invisible gravitational force, did not remain silent – but instead makes a comment that he will not provide a false or deceptive hypothesis, that the only useful scientific perspective is to collect and analyze data based on observable phenomenon and only then postulate laws

In a nutshell, Newton has given us a powerful and clear illustration of the ability of science to function as a tool in human understanding of the universe around us. Despite what we may desire, dream, imagine, or wish the natural world to be, we must put these things aside to work with what we can observe, measure and experiment with.

For more information

Isaac Newton - A biography
http://www.newton.cam.ac.uk/newtlife.html

17th Century Science, Mathematics and Astronomy Links
http://www.earlymodernweb.org.uk

Medieval Science - A history for kids
http://www.historyforkids.org/learn/medieval/science/