Overview

Eppur si mouve [and still it moves]

Galileo Galilei, 1632;

From ghoulies, gosties and long-legetty beasties

And things that go bump in the night,

Good Lord, deliver us!

The Cornish or West Country Litany

Francis T. Nettleinghame, 1926

Galileo Galilei (1564 1642) was probably the greatest scientist of the current era. The Encyclopedia Britannica lists, among his other achievements:

His insistence that the book of nature was written in the language of mathematics changed natural philosophy from a verbal qualitative account to a mathematical one in which experimentation became a recognised method for discovering the facts of nature.

In Galileo's time natural philosophers held the view (belief based on the authority of Aristotle only) that objects moved at speeds proportional to their masses, a view attributed to Aristotle's philosophical account of nature. In an early experiment, reputedly conducted from the balcony of the leaning tower of Pisa, Galileo dropped a musket ball and cannon ball, many times the mass of the musket ball, to see how fast they would fall. He found that both masses reached the ground at about the same time. From this experiment Galileo concluded, within some slight experimental error attributed to air resistance, that this result clearly refuted the inappropriate Aristotelian view of nature about falling masses.

With this, as well as many other similar basic experiments, Galileo firmly established the need and, indeed, the method for experimental verification of intuitive hypotheses about the nature of the universe. ^[6.1]

Engineering science is almost entirely...