Читать книгу String Theory For Dummies - Andrew Zimmerman Jones - Страница 34

Sir Isaac Newton developed his theory of gravity in the late 1600s. This amazing theory involved bringing together an understanding of astronomy and the principles of motion (known as mechanics or kinematics) into one comprehensive framework that also required the invention of a new form of mathematics: calculus. In Newton’s gravitational theory, objects are drawn together by a physical force that spans vast distances of space.

The key is that gravity binds all objects together (much like the Force in Star Wars). The apple falling from a tree and the moon’s motion around Earth are two manifestations of the exact same fundamental force.

The relationship that Newton discovered was a mathematical relationship (he did, after all, have to invent calculus to get it all to work out), just like relativity, quantum mechanics, and string theory.

In Newton’s gravitational theory, the force between two objects is based on the product of their masses, divided by the square of the distance between them. In other words, the heavier the two objects are, the more force there is between them, assuming the distance between them stays the same. (See the sidebar “A matter of mass” for clarification of this relationship.)