Sidereus Nuncius, or The Sidereal Messenger

Galileo Galilei, Albert Van Helden

• Publisher: University of Chicago Press
• Year: 2016
• ISBN:
  9780226320120
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

Galileo Galilei's Sidereus Nuncius is arguably the most dramatic scientific book ever published. It announced new and unexpected phenomena in the heavens, "unheard of through the ages, " revealed by a mysterious new instrument. Galileo had ingeniously improved the rudimentary "spyglasses" that appeared in Europe in 1608, and in the autumn of 1609 he pointed his new instrument at the sky, revealing astonishing sights: mountains on the moon, fixed stars invisible to the naked eye, individual stars in the Milky Way, and four moons around the planet Jupiter. These discoveries changed the terms of the debate between geocentric and heliocentric cosmology and helped ensure the eventual acceptance of the Copernican planetary system.Albert Van Helden's beautifully rendered and eminently readable translation is based on the Venice 1610 edition's original Latin text. An introduction, conclusion, and copious notes place the book in its historical and intellectual context, and a new preface, written by Van Helden, highlights recent discoveries in the field, including the detection of a forged copy of Sidereus Nuncius, and new understandings about the political complexities of Galileo's work.

SIDEREUS NUNCIUS

SIDEREAL MESSENGER

unfolding great and very wonderful sights

and displaying to the gaze of everyone,

but especially philosophers and astronomers,

the things that were observed by

GALILEO GALILEI,

Florentine patrician1

and public mathematician of the University of Padua,

with the help of a spyglass2 lately devised3 by him,

about the face of the Moon, countless fixed stars,

the Milky Way, nebulous stars,

but especially about

four planets

flying around the star of Jupiter at unequal intervals

and periods with wonderful swiftness;

which, unknown by anyone until this day,

the first author detected recently

and decided to name

MEDICEAN STARS4

Venice, at the press of Tommaso Baglioni. MDCX

With permission of the authorities and privilege

MOST SERENE
COSIMO II DE’ MEDICI
FOURTH GRAND DUKE OF TUSCANY5

A most excellent and kind service has been performed by those who defend from envy the great deeds of excellent men and have taken it upon themselves to preserve from oblivion and ruin names deserving of immortality. Because of this, images sculpted in marble or cast in bronze are passed down for the memory of posterity; because of this, statues, pedestrian as well as equestrian, are erected; because of this, too, the cost of columns and pyramids, as the poet says,6 rises to the stars; and because of this, finally, cities are built distinguished by the names of those who grateful posterity thought should be commended to eternity. For such is the condition of the human mind that unless continuously struck by images of things rushing into it from the outside, all memories easily escape from it.

Others, however, looking to more permanent and long-lasting things, have entrusted the eternal celebration of the greatest men not to marbles and metals but rather to the care of the Muses and to incorruptible monuments of letters. But why do I mention these things as though human ingenuity, content with these [earthly] realms, has not dared to proceed beyond them? Indeed, looking further off, and knowing full well that all human monuments perish in the end through violence, weather, or old age, this human ingenuity contrived more incorruptible symbols against which voracious time and envious old age can lay no claim. And thus, moving to the heavens, it assigned to the familiar and eternal orbs of the most brilliant stars the names of those who, because of their illustrious and almost divine exploits, were judged worthy to enjoy with the stars an eternal life. As a result, the fame of Jupiter, Mars, Mercury, Hercules, and other heroes by whose names the stars are called will not be obscured before the splendor of the stars themselves is extinguished. This especially noble and admirable invention of human sagacity, however, has been out of use for many generations, with the pristine heroes occupying those bright places and keeping them as though by right. In vain Augustus’s piety tried to place Julius Caesar in their number, for when he wished to name a star (one of those the Greeks call Cometa and we call hairy)7 that had appeared in his time the Julian star, it mocked the hope of so much desire by disappearing shortly.8 But now, Most Serene Prince, we are able to augur far truer and more felicitous things for Your Highness, for scarcely have the immortal graces of your soul begun to shine forth on earth than bright stars offer themselves in the heavens which, like tongues, will speak of and celebrate your most excellent virtues for all time. Behold, therefore, four stars reserved for your illustrious name, and not of the common sort and multitude of the less notable fixed stars, but of the illustrious order of wandering stars, which, indeed, make their journeys and orbits with a marvelous speed around the star of Jupiter, the most noble of them all, like his own children, with mutually different motions, while meanwhile all together, in mutual harmony, complete their great revolutions every twelve years about the center of the world, that is, about the Sun itself.9 Indeed, it appears that the Maker of the Stars himself, by clear arguments, admonished me to reserve for these new planets the illustrious name of Your Highness before all others. For as these stars, like the offspring worthy of Jupiter, never depart from his10 side except for the smallest distance, so who does not know the clemency, the gentleness of spirit, the agreeableness of manners, the splendor of the royal blood, the majesty in actions, and the breadth of authority and rule over others, all of which qualities find a domicile and home for themselves in Your Highness? Who, I say, does not know that all these emanate from Jupiter, the most beneficent star according to the plan of God, who is the source of all good? It was Jupiter, I say, who at Your Highness’s birth, having already passed through the murky vapors of the horizon, and occupying the midheaven11 and illuminating the eastern angle12 from his royal house, looked down upon Your most fortunate birth from that sublime throne and poured out all his splendor and grandeur into the most pure air, so that with its first breath Your tender little body could drink in, together with Your soul (already decorated by God with noble ornaments), this universal power and authority. But why do I use probable arguments when I can deduce and demonstrate it from all but necessary reason? It pleased Almighty God that I was deemed not unworthy by Your serene parents to undertake the task of instructing Your Highness in the mathematical disciplines, which task I fulfilled during the past four years, at that time of the year when it is the custom to rest from more severe studies. Therefore, since I was evidently influenced by divine inspiration to serve Your Highness and to receive from so close the rays of your incredible clemency and kindness, is it any wonder that my soul was so inflamed that day and night it reflected on almost nothing else than that I, who am not only in soul but also by origin and nature under Your dominion, be recognized as full of ardor for Your glory and the utmost gratitude toward Your person. And hence, since under Your auspices, Most Serene Cosimo, I discovered these stars unknown to all previous astronomers, I decided by the highest right to adorn them with the very august name of Your family. For if I first discovered them, who will deny me the right if I also assign them a name and call them the Medicean Stars,13 hoping that perhaps so much honor will accrue to these stars from this naming as the other stars brought to the rest of the Heroes? For, to be silent about Your Most Serene Highness’s ancestors to whose eternal glory the monuments of all histories testify,14 Your virtue alone, Greatest of Heroes, can confer on these stars an immortal name. For who can doubt that the expectation of Yourself which you have aroused by the most blessed beginning of Your reign—even though it is of the highest—not only will you sustain and preserve, but that Your destiny is to surpass it by a great margin? So that having vanquished your compeers, even so You vie with Yourself and day by day emerge ever greater than Yourself and Your grandeur.

Therefore, Most Merciful Prince, receive from the stars this glory reserved for Yourself and Your family; and may You enjoy that divine good bestowed on You not so much by the stars as by the Maker and Governor of the stars, namely God, for as long a time as possible.

Written in Padua on the fourth day before the Ides of March,15 1610.

Your Highness’s most loyal servant,

Galileo Galilei

The undersigned Gentlemen, Heads of the Council of Ten,16 having received certification from the Reformers of the University of Padua,17 by report from the Gentlemen deputized for this matter, that is, from the Most Reverend Father Inquisitor and from circumspect Secretary of the Senate, Giovanni Maraviglia, with an oath, that in the book entitled Sidereus Nuncius by Galileo Galilei there is nothing contrary to the Holy Catholic Faith, Principles, or good customs, and that it is worthy of being printed, allow it a license so that it can be printed in this city.

Written on the first day of March 1610

M. Ant. Valaresso
Nicolo Bon	Heads of the Council of Ten
Lunardo Marcello

The Secretary of the Most Illustrious Council of Ten

Bartholomaeus Cominus

1610, on 8...