Telescopes, Tides, and Tactics: A Galilean Dialogue about The Starry Messenger and Systems of the World

by Stillman Drake

Publication of Galileo's Starry Messenger in 1610, detailing startling observations with the newly invented telescope, sparked immediate furor among the astronomers and philosophers of the day. The discovery of the "Medicean stars" (the satellites of Jupiter) was pronounced a hoax, an optical illusion, a logical and theological impossibility. Stillman Drake, one of the world's foremost Galileo scholars, recreates in Telescopes, Tides, and Tactics the fascinating aftermath of the publication of the Starry Messenger . Drawing on Galileo's scientific working papers and the letters and notebooks of his colleagues, Drake presents an imaginative Galilean dialogue using the text of the Starry Messenger as a departure point for discussions of appropriate scientific method, new discoveries, and the emergence of a new world view at this early stage of the Scientific Revolution.

Drake has revised his earlier abridged translation of the Starry Messenger , and for the first time the entire work is presented here in modern English. No other edition or translation of this famous work has analyzed Galileo's recorded observations in detail, compared them with modern calculations, or explained the later use he made of them. In the accompanying fictional dialogue, Salviati, Sagredo, and Sarpi reread the Starry Messenger in 1613 and discuss events and issues raised in the three years since its publication. Much of the dialogue is based on archival materials not previously cited in English. Drake has unearthed a wealth of information that will interest the lay reader as well as the historian and the scientist—descriptions of the various and occasionally bizarre critics of Galileo, a reconstruction of Galileo's promised book on the system of the world, his tables of observations and calculations of satellite motions, and evidence for an early tide theory. It was this theory explaining tides by motions of the earth, rather than the influence of Platonic metaphysics, Drake argues that played a major role in Galileo's acceptance of Copernican astronomy.

Telescopes, Tides, and Tactics is a thorough portrait of Galileo as a working astronomer. Offering much more than a commentary on the Starry Messenger , Drake has written a novel and absorbing contribution to the history of physics and astronomy and the study of the Scientific Revolution.

256 pages, Hardcover

First published July 1, 1983

About the author

Stillman Drake was a Canadian historian of science best known for his work on Galileo Galilei.

Reviews

[Vasha7]

This is a really nice way to accompany the text of the Starry Messenger with discussions of the methods Galileo used to make the observations; errors and their causes; follow-up observations that Galileo made after the book was hastily published; and contemporaries' responses to it. The "dialogue" is a little stilted, but really not bad at all -- the "participants" seem human enough, and even though they don't disagree with each other as in most "dialogues", they do ask for clarification and chip in alternate suggestions, which helps to "lighten" the reading.

I have to admit that I didn't take the trouble to work through some of the arguments in detail: I'd just say to myself, "Here follows a trigonometric demonstration of argument Z, let me take Z for granted." I also skimmed all the observations of Jupiter's positions. However, I did appreciate reading through how Galileo showed that the glow seen on the dark parts of the Moon is reflected light from the Earth. Turns out, too, that this is a contradiction of medieval cosmology, which would have assumed that the earth did not shed light. Also, even though I didn't fully understand the proof, it was interesting to learn that the phenomenon of the eclipses of the moons of Jupiter was a disproof of Ptolemy's astronomy, like the better-known phases of Venus; no wonder that the latter gets more publicity, since it's more easily understood by a layperson.

One of the topics that Drake hopes to address in this book is why many philosophers refused to look through Galileo's telescope: "...a mere optical phenomenon, not regarded by most philosophers as even relevant to a book about so sublime and grave a subject as the system of the universe, and hardly worthy of consideration except by mere mathematicians. Occasional and incidental appearances are not taken by philosophers to be proper bases from which one may reason about the structure of the world..." (However, "Aristotle... taught that a single contrary experience outweighs any amount of subtle reasoning.")

Drake really took this as a lead-up to Galileo's description of the "system of the world", so long delayed; he shows that as well as spending years collecting observations, and hypotheses derived from observations -- in particular, finding phenomena that link earthly and heavenly motion, such as the tides -- Galileo was trying to prepare the ground for the reception of his major work by establishing that it was appropriate to do science by observation at all -- a view that had all too few partisans at the time of this dialogue, 1613.

[Michael Boerman]

summary: galileo calls the RC church stupid, RC church burns his books or whatever and puts him under house arrest bc he made fun of them, galileo goes blind, galileo dies alone.