Discourse On Floating Bodies

As to the first, the last discoveries of Saturn to be tricorporeall, and of the mutations of Figure in Venus, like to those that are seen in the Moon, together with the Consequents depending thereupon, have not so much occasioned the demur, as the investigation of the times of the Conversions of each of the Four Medicean Planets about Jupiter, which I lighted upon in April the year past, 1611, at my being in Rome; where, in the end, I assertained my selfe, that the first and neerest to Jupiter, moved about 8 gr. & 29 m. of its Sphere in an houre, makeing its whole revolution in one naturall day, and 18 hours, and almost an halfe. The second moves in its Orbe 14 gr. 13 min. or very neer, in an hour, and its compleat conversion is consummate in 3 dayes, 13 hours, and one third, or thereabouts. The third passeth in an hour, 2 gr. 6 min. little more or less of its Circle, and measures it all in 7 dayes, 4 hours, or very neer. The fourth, and more remote than the rest, goes in one houre, 0 gr 54 min. and almost an halfe of its Sphere, and finisheth it all in 16 dayes, and very neer 18 hours. But because the excessive velocity of their returns or restitutions, requires a most scrupulous precisenesse to calculate their places, in times past and future, especially if the time be for many Moneths or Years; I am therefore forced, with other Observations, and more exact than the former, and in times more remote from one another, to correct the Tables of such Motions, and limit them even to the shortest moment: for such exactnesse my first Observations suffice not; not only in regard of the short intervals of Time, but because I had not as then found out a way to measure the distances between the said Planets by any Instrument: I Observed such Intervals with simple relation to the Diameter of the Body of Jupiter; taken, as we have said, by the eye, the which, though they admit not errors of above a Minute, yet they suffice not for the determination of the exact greatness of the Spheres of those Stars. But now that I have hit upon a way of taking such measures without failing, scarce in a very few Seconds, I will continue the observation to the very occultation of JUPITER, which shall serve to bring us to the perfect knowledge of the Motions, and Magnitudes of the Orbes of the said Planets, together also with some other consequences thence arising. I adde to these things the observation of some obscure Spots, which are discovered in the Solar Body, which changing, position in that, propounds to our consideration a great argument either that the Sun revolves in it selfe, or that perhaps other Starrs, in like manner as Venus and Mercury, revolve about it, invisible in other times, by reason of their small digressions, lesse than that of Mercury, and only visible when they interpose between the Sun and our eye, or else hint the truth of both this and that; the certainty of which things ought not to be contemned, nor omitted.

Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

"A Discourse on Floating Bodies" from Galileo Galilei. Italian physicist, mathematician, astronomer, and philosopher (1564-1642).

This 1612 essay challenged Aristotelian physics by asserting that sunspots are actual spots on the surface of the sun or in its atmosphere, rather than satellites. Introduction. Explanatory Notes. Index.

A suspenseful narrative and spiritive rendition of the life of Galileo.

Galileo, one of history's best-known scientists, is introduced in this illuminating activity book. Children will learn how Galileo's revolutionary discoveries and sometimes controversial theories changed his world and laid the groundwork for modern astronomy and physics. This book will inspire kids to be stargazers and future astronauts or scientists as they discover Galileo's life and work. Activities allow children to try some of his theories on their own, with experiments that include playing with gravity and motion, making a pendulum, observing the moon, and painting with light and shadow. Along with the scientific aspects of Galileo's life, his passion for music and art are discussed and exemplified by period engravings, maps, and prints. A time line, glossary, and listings of major science museums, planetariums, and web sites for further exploration complement this activity book.

This volume makes an important contribution toward a nuanced appreciation of the Jesuits' interaction with "modernity", and a greater recognition of their contribution to the mathematization of natural philosophy and experimental science. The six essays provide a cross-section of the complex Jesuit encounter with the mathematical sciences during the 17th century.

Informed by currents in sociology, cultural anthropology, and literary theory, Galileo, Courtier is neither a biography nor a conventional history of science. In the court of the Medicis and the Vatican, Galileo fashioned both his career and his science to the demands of patronage and its complex systems of wealth, power, and prestige. Biagioli argues that Galileo's courtly role was integral to his science—the questions he chose to examine, his methods, even his conclusions. Galileo, Courtier is a fascinating cultural and social history of science highlighting the workings of power, patronage, and credibility in the development of science.