Thus Spoke Galileo: The Great Scientist's Ideas and their Relevance to the Present Day

  • Andrea Frova &
  • Mariapiera Marenzana
transl. by Jim McManus Oxford University Press: 2006. 512 pp. $34.50, £19.99 0198566255 | ISBN: 0-198-56625-5

Galileo Galilei is known as one of the founders of modern science. But his works, as well as those of co-founders such as Isaac Newton, are seldom read. It is not that they are in some exotic language: Newton wrote in Latin, Galileo mainly in a limpid, straightforward Italian, in contrast to the baroque style of many of his contemporaries. As well as science, Galileo is a major figure in Italian history and literature. Italian high schools teach his dramatic life and prosecution by the Inquisition. But professional historians of science aside, few Italians have read many of his works.

The problem is that we must understand the scientific questions, knowledge and — most importantly — prejudices of the time. Changes in scientific notation make the scientific papers of even a century ago all but unintelligible to today's experts, so it is no surprise that scientists are seldom moved to read 400-year-old books of physics whose scientific context almost completely escapes them.

Thus Spoke Galileo by Andrea Frova and Mariapiera Marenzana, an attempt to bring Galileo's work to general readers, should solve this problem. The texts are introduced in their correct and precise historical context, framed to stimulate the reader's curiosity.

The book opens with an imaginary autobiography, composed of a collage of letters and other documents written by Galileo, interpolated with writings from Frova and Marenzana in Galileo's style. Galileo tells his life story, discussing the clash with the Church that eventually led him to disown his writing. It is a portrait of a complex man, with light and shade. He was frank, but also able to adapt himself to difficult times: he knew that his forced abjuration was only a momentary defeat, and that in the long run, with the help of his students, his ideas would triumph.

Each of the other chapters deals with a specific topic. They begin with a summary of the knowledge at that time, followed by Galileo's writings on the subject. The most crucial points are put in his words; the rest of the argument is summarized. Often the chapter ends with a short historical excursus where, presenting the same ideas in modern scientific language, the authors show the impact of Galileo's ideas on subsequent science.

To understand the originality and ingenuity of a scientist we must compare his statements with those of his contemporaries. It turns out that Galileo leant on the work of other scientists more than is commonly believed: the famous example of the ship in motion is taken from Giordano Bruno, and an argument on the fall of a heavy body comes from Giovanni Battista Benedetti. Galileo's unique skill was to weave empirical observations into a coherent picture. He also used state-of-the-art technology to build and develop instruments of scientific observation, such as the telescope and the microscope, that, through their widespread use, went on to fundamentally influence later science.

The book is remarkable for its clarity, precision and historical accuracy. Numerous drawings, figures and photographs help the reader pick a path through the historical and scientific reconstruction.

Nowadays scientific knowledge is extraordinarily developed and university education promotes hyper-specialization. Scientists who end up working in two different fields may struggle, owing to an insufficient depth of knowledge in either one. This book reminds us that things have not been always this way: as the authors note in their introduction, the excerpts from Galileo's writings have been chosen to offer a vision of his multiple interests in many scientific and cultural fields, “of his prodigious curiosity for all natural phenomena, of his inexhaustible capacity for posing questions to himself and searching for answers by reasoning. And also of his exultation at making discoveries.”