On The Revolutions of Heavenly Spheres

by Nicolaus Copernicus, Stephen Hawking

New to our On the Shoulders of Giants series, this groundbreaking work of astronomy proposed a heliocentric universe in which planets orbited the sun-daring to challenge the Ptolemaic ideal of the earth as the center of the universe. This essay by Copernicus (1473-1543), revolutionized the way we look at the earth's placement in the universe, and paved the way for many great scientists, including Galileo and Isaac Newton, whose theories stemmed from this model. Featuring a biography of Copernicus and an accessible, enlightening introduction, both written by the renowned physicist Stephen Hawking, On the Revolution of Heavenly Spheres provides a fascinating look at the theories which shaped our modern understanding of astronomy and physics.

Genres: Science, Classics, Nonfiction, Physics, Astronomy, Philosophy, History

408 pages, Paperback

First published January 1, 1543

About the author

The Ptolemaic system dominated medieval cosmology; Nicolaus Copernicus, Polish astronomer, proposed a heliocentric model of the universe and thus contradicted it.

Polish name: Mikołaj Kopernik

This mathematician studied canon law and medicine at Kraków, Bologna, Rome, Padua, and Ferrara. Copernicus published an interesting early description of his Solar System in Commentariolus in (1512. Ancients invented the equant point, a known device, which actually not exactly slightly offset the Solar System. After not new theories of Aristarchus of Samos and Nicholas of Cusa, Copernicus also worked out his similar idea Solar System in full mathematical detail. The not simpler mathematics in his description required even fewer basic assumptions. Copernicus postulated only the tilt of rotational axis of the Earth and revolution about the Sun and observed and thus ably explained the motion of the heavens. Copernicus, however, retained circular orbits and consequently required the inclusion of epicycles. Copernicus feared that his ideas perhaps got trouble with the Church and unfortunately therefore delayed publication.

In 1539, Copernicus took on Georg Joachim Rheticus as a student and handed over his manuscript to write, to publish, and to popularize the theory as Narratio Prima in 1540. Rheticus convinced Copernicus to allow publication of De Revolutionibus Orbium Coelestium in 1543, shortly before his death. Theory of Copernicus as a true description not just saved appearances. Only a single true, valid theory saved not appearances, Copernicus, unlike Jean Buridan and Nicole Oresme, instead thought. When people published the work, however, Andreas Osiander added an unauthorized preface, which stated that the contents, a device, merely simplified calculations.

Copernicus adapted physics to the demands and thought of the incorrect principles, not the math or observations. He, the first such person in history, created a complete and general combination of mathematics and physics. Forebears for instance treated each planet separately. People taught Copernicus in the 1500s, but he permeated the academic world not until 1600. The most influential John Donne and William Shakespeare feared theory of Copernicus, which destroyed hierarchical natural and social order in turn and brought about chaos. Indeed, some persons, such as Giordano Bruno, used theory of Copernicus to justify radical theological views.

Europe stagnated before Copernicus formulated his theory of the Solar System. After people translated the Almagest, which already laid out flaws, into Latin, Europeans, such as Georg von Peurbach, the Austrian mathematician, and Johann Müller (Regiomontanus), the German, attempting instead to refine the old theories. Since the 1200s, people still used The Sphere, the textbook, for teaching. "Saving appearances" consisted of trying cumbersome and inaccurate patches, rather than formulating new theories. Copernicus, however, wiped the clean slate in a single broad stroke, and in a fundamentally difference, all planets circled the Sun in De Revolutionibus Orbium Coelestium. Copernicus stated a radically different but hardly original idea and theory.

Reviews

[Orhan Pelinkovic · Rating 4 out of 5]

I've heard so much of him, but never from him, so I decided to read Nicolaus Copernicus's (1473-1543) own book On the Revolutions of Heavenly Spheres and hear his thoughts and findings at first hand.

Copernicus, an astronomer and mathematician, comprehensively presents his heliocentric theory in which the Earth and other planets revolve around the Sun. This heliocentric model ended up replacing the geocentric model. Essentially, Copernicus, a Polish Catholic clergyman, with substantiated mathematical calculations and observations, swapped Earth's and Sun's position, and initiated the Scientific Revolution.

We are given precise measurements of duration, dimensions, positions and movements of Earth's precession, axial tilt, equinoxes, solstices, rotation, and revolutions. Furthermore, the Moon's and other planets (except Uranus and Neptune) of the solar system precise position, shape and path of their orbits. Copernicus compares his finding with renowned astronomers, such as, Claudius Ptolemy (c.100-170 CE) and Muhammad Al-Battani (c.858-929 CE). Copernicus, does say that Sun is at the center of the universe (it's not), and the Sun and stars do not move (they do) but this does not diminish anything, as science is a work in progress, and he paved a clear path for future generations to continue where he left off.

This book is heavy on Euclidean geometry. I am not sure if I would recommend it, unless you're into this stuff or this is where your curiosity is at the moment. The book is well written, but reading it requires you to constantly bounce back-and-forth from the textual part to the geometrical diagrams. This can be tiring, and at times, reading it, felt like a chore.

Since the book was written 500 years ago, it was fun for me read how he divides the radius of a circle in 1,000, 10,000 or 100,000 parts for calculation purposes. Today we mostly use the metric units (some imperial) which essentially derived for the 'parts' approach. Also, Copernicus states that the north hemisphere has a total of 360 stars, with the Zodiac having 346 stars, and the Southern hemisphere 316 stars. It was rather interesting to see how an astronomer, in their academic work, gives the Zodiac a category of its own and a section of the sky, where in modern astronomy books, astronomers assign no significance to the Zodiac, but it was fun to read about it.

Copernicus mentions a couple of times the astronomer and mathematician Aristarchus of Samos (c.310-230 BCE) and his calculations and findings, but does not mention that it was, Aristarchus, that is first known to present the heliocentric model. Perhaps, Copernicus wasn't aware? Maybe, we'll never know.

Copernicus also uses, for some of his scientific calculations of time, Alexander the Great death as a point of reference for his year notations (instead of only using BC and AD), and also makes use of the Egyptian calendar, as he says is very suitable for calculating uniform motions. But this can also be seen as a rebellious act against the Church, which it probably was, or a step in the direction of separating science from religion. All in all, Copernicus, with this book, corrects our view of the universe, and the perspective of our significance in it.

[Riku Sayuj · Rating 4 out of 5]

The Earth is Spherical, Small, Mobile (triply so), Certainly Not the Center of the Universe, and thus imperfect from now on.

Having said that, so far as hypotheses are concerned, let no one expect anything certain from Science, which cannot furnish it, lest he accept as the truth ideas conceived for another purpose, and depart from this study a greater fool than when he entered it. Farewell.

[Roy Lotz · Rating 4 out of 5]

And though all these things are difficult, almost inconceivable, and quite contrary to the opinion of the multitude, nevertheless in what follows we will with God’s help make them clearer than day—at least for those who are not ignorant of the art of mathematics.

The Copernican Revolution has become the prime exemplar of all the great transformations in our knowledge of the world—a symbol of scientific advance, the paradigmatic clash of reason and religion, a shining illustration of how cold logic can beat out old prejudices. Yet reading this groundbreaking book immediately after attempting Ptolemy’s Almagest—the Bible of geocentric astronomy—reveals far more similarities than differences. Otto Neugebauer was correct in calling Copernicus’s system an ingenious modification of Hellenistic astronomy, for it must be read against the background of Ptolemy in order to grasp its significance.

The most famous section of De revolutionibus was, ironically, not even written by Copernicus, but by the presumptuous Andreas Osiander, a Lutheran theologian who was overseeing the publication of the book, and who included a short preface without consulting or informing Copernicus. Knowing that Copernicus’s hypothesis could prove controversial (Luther considered it heretical), Osiander attempted to minimize its danger by asserting that it was merely a way of calculating celestial positions and did not represent physical reality: “for it is not necessary that the hypotheses should be true, or even probable; but it is enough if they provide a calculate which fits the observations.”

Though this assertion obviously contradicts the body of the work (in which Copernicus argues at length for the reality of the earth’s movement), and though Copernicus and his friends were outraged by the insertion, it did help to shield the book from censure. And arguably Osiander was being a good and true Popperian—believing that science is concerned with making accurate predictions, not in giving us “the truth.” In any case, Osiander was no doubt correct in this assertion: “For it is sufficiently clear that this art is absolutely and profoundly ignorant of the causes of the apparent irregular movements.” Neither Ptolemy nor Copernicus had any coherent explanation of what caused the orbits of the planets, which would not come until Einstein.

After this little interpolation, Copernicus himself wastes no time in proclaiming the mobility of the earth. In retrospect, it is remarkable that it took such a long stretch of history for the heliocentric idea to emerge. For it instantly explains many phenomena which, in the Ptolemaic system, are completely baffling. Why do the inner planets (Venus and Mercury) move within a fixed distance of the sun? Why does the perigee (the closest point in the orbit) of the outer planets (Mars, Jupiter, Saturn) occur when they are at opposition (i.e., when they are opposite in the sky from the sun), and why does their apogee (the farthest point) occur when they are in conjunction (when they are hidden behind the sun)? And why do the planets sometimes appear to move backwards relative to the fixed stars?

But putting the earth in orbit between Venus and Mars neatly and instantly explains all of these mysteries. Mercury and Venus always appear a fixed distance from the sun because they are orbiting within the earth’s orbital circle, and thus from our position appear to go back and forth around the sun. Mars, Jupiter, and Saturn, by contrast, can appear at any longitudinal distance from the sun because their orbits are outsider ours; but if Mars' orbit were tracked from Jupiter, for example, it would, like Venus and Mercury, appear to go back and forth around the sun. Also note that Mars will appear to go “backwards” from earth when earth overtakes the red planet, due to our planet’s shorter orbital period. And since Mars will be closest when it is on the same side of the sun as earth (opposition from the sun), and furthest when it is on far side of the sun (conjunction with the sun), this also explains the apogee and perigee positions of the outer planets.

This allows Copernicus to collapse five circles—one for each of the planets, which were needed in the Ptolemaic system to account for these anomalies—into one circle: namely, the earth’s orbit. The advantages are palpable.

Nevertheless, while I think the benefits of putting the planets in orbit around the sun are obvious, perhaps even to a traditionalist, it is not obvious why Copernicus should put the earth in motion around the sun rather than the reverse. Indeed, this is exactly what the eminent astronomer Tycho Brahe did, several generations later. For it makes no observational difference whether the sun or the earth is in motion. And in the Aristotelian physics of the time, the former solution makes a great deal more sense, since the heavens were supposed to be constituted of lightest elements and the earth of the heaviest elements. So how could the heavy earth move so quickly? What is more, there is no concept of inertia in Aristotelian physics, and so no explanation for why people would not fly off the earth if it were in rapid motion.

Copernicus takes a brief stab at answering these obvious counterarguments, even offering a primitive notion of inertia: “As a matter of fact, when a ship floats on over a tranquil sea, all the things outside seem to the voyagers to be moving in a movement which is the image of their own, and they think on the contrary that they themselves and all the things with them are at rest.” Even so, it is obvious that such a brief example does not suffice to refute the entire Aristotelian system. Clearly, a whole new concept of physics was needed if the earth was to be in motion, one which did not arrive until Isaac Newton, born nearly two hundred years after Copernicus. It took a certain amount of boldness, or obtuseness, for Copernicus to proclaim the earth’s motion without at all being able to explain how the heaviest object in the universe—or so they believed—could hurtle through space.

In structure and content, De revolutionibus follows the Algamest pretty closely: beginning with mathematical preliminaries, onward to the orbits of the sun (or, in this case the earth), the moon, and the planets—with plenty of tables to aid calculation—as well as a description of his astronomical instruments and a chart of star locations, and finally ending with deviations in celestial latitude (how far the planets deviate north and south from the ecliptic in their orbits). Copernicus was even more wedded than Ptolemy to the belief that celestial objects travel in perfect circles, which leads him to repudiate Ptolemy’s use of the equant (the point around which a planet moves at a constant speed). The use of the equant upset Copernicus’s sense of elegance, you see, since its center is different from the actual orbit’s center, thus requiring two overlapping circles.

Copernicus’s own solution was an epicyclet, which revolves twice westward (clockwise, from the celestial north pole) for each rotation eastward on the deferent. And so, ironically, though Ptolemy is sometimes mocked for using epicycles, Copernicus followed the same path. I also find it amusing that the combined effect of these circular motions, in both Ptolemy and Copernicus, added up to a non-circular orbit; clearly nature had different notions of elegance than these astronomers. In any case, it would have to wait until Kepler that it was realized that the planets actually follow an ellipse.

Perhaps the greatest irony is that Copernicus’s book is not any easier to use than Ptolemy’s as a recipe book for planetary positions. Now, it is far beyond my powers to even attempt such a calculation. But in his Very Short Introduction to Copernicus (which I recommend), Owen Gingerich takes the reader through the steps to calculation the position of Mars on Copernicus’s birthday: February 19, 1473. To do this you needed the radix, which is a root position of the planet recorded at a specified time; and you also need the planet’s orbital speed (the time needed for one complete orbit, in this case 687 days). The year must be converted into sexigesimal (base 60) system, and then converted in elapsed Egyptian years (which lack a leap year), in order to calculate the time elapsed since the date of the radix’s position (in this case is January 1st, 1 AD). Then this sexigesimal number can be looked up in Copernicus’s tables; but this only gives us the location of Mars with respect to the sun. To find out where it will appear in the sky, we also need the location of earth, which is another tedious process. You get the idea.

I read the bulk of this book while I was on vacation in rural Canada. Faced with the choice between relaxation or self-torture, I naturally chose the latter. While most of my time was spent scratching my head and helplessly scratching the page with a pencil, the experience was enough to show me—as if I needed more demonstration after Ptolemy—that astronomy is not for the faint of heart, but requires intelligence, patience, and care.

There was one advantage to reading the book on vacation. For it is the only time of year when I am in a place without light pollution. The stars, normally hiding behind street lights and apartment buildings, shone in the hundreds. I would have seen even more were it not for the waxing moon. But this did give me the opportunity to get out an old telescope—bought as a birthday present for a cousin, over a decade ago—and examine the moon’s pitted surface. It is humbling to think that even such basic technology was years ahead of Copernicus’s time.

Looking at the brilliant grey circle, surrounded by a halo of white light, I felt connected to the generations of curious souls who looked at the same moon and the same stars, searching for answers. So Copernicus did not, in other words, entirely spoil my vacation.

[Markus · Rating 5 out of 5]

Les Fondateurs de L'Astronomie Moderne by Joseph Louis François Bertrand
Les Fondateurs de L'Astronomie Moderne: Copernic, Tycho Brahe, Kepler, Galilee, Newton
by Joseph Louis François Bertrand

48327873
Markus's review
Apr 10, 2019, · edit

bookshelves: biography, history, philosophy, read-in-french, science

Les Fondateurs de l’Astronomie Moderne
Copernic, Tycho Brahé, Kepler, Galilée, Newton.
By Joseph Bertrand (1822-1900)

This edition originally published in 1865, provides a short biography and a summary of the works of these four giants of the history of astronomy.

Copernic (1472 – 1543)
Brahe (1546 – 1601)
Kepler (1571 – 1630)
Galileo (1564 – 1642)
Newton (1642 – 1727)

From their overlapping lifespans, we may guess that the time had come for the revolution of the science of astronomy to have its natural eclosion.

Copernic a quiet and modest man born in Poland, opened the treasure trove of Ancient Greeks writings to understand and establish the theory of the rotating earth around the sun. (Heliocentricity)

Tycho Brahe from a noble family, born in Denmark did not adhere to Copernicus's findings but was the astronomer who developed at the right time a system of precise observation of the planets and stars. To achieve this endeavor, he invented and constructed the necessary scientific tools and equipment.

Kepler of modest origins, born in Germany became a passionate and persevering scientist who believed and followed up on the theories of Copernic.
He had been associated with Tycho Brahe and using his substantial documented findings understood and established the rules of the movements of the elliptical and not circular path of the planets and stars.

Galileo Galilei, was the celebrated Italian astronomer, mathematician, and physicist, with a significant number of scientific discoveries and inventions.
He believed in Copernic’s theory and used a telescope to look into the night sky. He discovered several planetary satellites and confirmed that the earth was just another planet rotating around the sun.
However, that was not how the Holy scriptures described the Creation. He was a personal friend of the Pope, but a victim of the Catholic Inquisition, and under threat of torture, he publicly retracted his theories and was convicted to life in prison.

Isaac Newton was the greatest of British scientists, physicists, mathematicians, and astronomers.
He made numerous scientific discoveries that he published during his lifetime.
Had the genius to explain the origin of the energy moving the Universe, Gravity.
An apple on a tree is attracted by the earth’s gravity and falls to the ground.
The sun’s gravitational forces attract the earth and the other rotating planets, and the mutual attraction keeps them rotating. And so for the stars and planets of the Universe.

These short comments can hardly do justice to the detailed works of discoveries mentioned in this book. And yet it is only a short and condensed work in itself. More reading is available and necessary to understand just a little of it all.

The lives of these men were wonderful adventures, full of enthusiasm, intelligence, and wit, of learned knowledge, perseverance, and luck to live at their place at the right time.

[Deepti · Rating 4 out of 5]

Thanks for starting the Copernican revolution which greatly impacted the scientific revolution and thereby completely changed our world views. We wouldn't be where we are today without you.

[Xander · Rating 2 out of 5]

In De Revolutionibus (1543), Copernicus published his ground breaking heliocentric theory.

During the first millennium, astronomers and theologians used the Ptolemaic system, which in essence consisted of this:

1. The earth is in the centre of the cosmos.
2. All planets, moon and sun revolve in orbits around the earth - this they do in cristalline spheres.
3. The outer cirstalline sphere contains all the stars.

To accord for all the discrepancies (for example: some planets, like Venus, have a retrograde motion through the sky) had to be solved with obscure mathematical devices like equants, epicylces and deferrents.

This led to the practical problem of how cristalline spheres, being made of matter (i.e. Aristotle's quintessence) could account for these mathematical movements? Wouldn't the spheres shatter? Another practical problem was the use of the Ptolemaic system for calculating the calender. During the centuries the discrepancies and flaws built up, so once in a while a 'reset' of the system was necessary. A third problem with the Ptolemaic universe was the sheer complexity of movements and mathematical constructs. Only the most learned geometricians and astronomers could work with this system.

One could say that by the time of Copernicus there was a need for a new, more accurate and more simpler celestial system. Copernicus did exactly this. He put the sun in the middle of the cosmos, and by doing this was able to come up with a mathematically simpler (therefore more beautiful) system - more easier to work with, more pleasing to the eye (of the beholder) and logically more consistent. (Ockham's razor: simplicity is a criterium to decide between scientific theories).

The main problem with this new system was, of course, that theologians and philosophers were basing their whole worldview on Aristotle and Aquinas. This didn't leave much room for a heliocentric assumption. E.g. in the book Joshua it says that Joshua commanded God to let the sun stand still - this becomes problematic when you have the sun as a centre of the universe.

Another problem - or rather collection of problems - was that Copernicus' system went against common sense notions. If the earth is moving around the sun, how come we don't fly off our planet? We see the starry heaven, the planets and the sun and moon move through the sky, right? This new system sounded highly speculative to contemporaries.

A third important point on Copernicus is that he was a neoplatonist. During Copernicus' time, the works of neoplatonists like Plotinus were re-discovered. According to this philosopical school, the sun has supernatural powers. One can easily see where Copernicus found his motivation to put the sun in the centre of the cosmos and do away with the geocentric worldview.

In all, this is a historical book, an important turning point in history. But it wasn't until Newton's synthesis in 1687 that the Copernican system became part of a whole new philosophy of the world. This was because there was no objective, scientific criterium by which to judge between Ptolemy and Copernicus. Both had their pros and cons; but there was no deciding piece of evidence.

This piece of evidence was delivered by Galilei, who discovered with his telescope the phases of Venus; this showed that Venus revolved around the sun and not the earth. (He also found many other interesting things with his telescope, to note: satellites around other planets, sunspots, craters on the moon's surface, etc.).

In the decades after the publication of De Revolutionibus, the book largely went by unnoticed - apart from some up-to-date astronomers. With the works of Tycho Brahe, Johannes Kepler and Galileo Galilei, the Copernican system became more widely diffused in intellectual circles and more accessible to non-astronomers, and it was only then (after Galilei's discoveries with the telescope) that the Inquisition put De Revolutionibus on the Index of Forbidden Books.

No matter the historical worth of this book, I can't really give this book a high score. It is extremely dense and technical. I'd bet that the average person can read the first 25 pages; after this it gets almost impossible to follow. I used this book mainly as a source of additional information to a physics textbook. I didn't need to read the whole book: so take my review with a grain of salt.

[Matt]

It wasn’t until some 70 years later, helped by Galileo‘s stubbornness, that the heliocentric universe posited by Copernicus’ book resulted in the Roman Catholic Church decree that heliocentrism was heresy. Copernicus expressed his fear of this reaction, or more likely the scorn of the mathematical community, in his Preface and Dedication to Pope Paul III. With great humility, he submitted the work as a life-long product of observation and study. Despite his fears of discarding a thousand years of a Ptolemic, geocentric universe, he asserted that “[m]athematics is written for mathematicians…” pg. 7. Copernicus is quietly assured of the value of his calculations. He also finds support from his theory among history. Copernicus notes Cicero mentioned Nicetas thought the Earth moved and that Plutarch wrote that Philolaus the Pythagorean said the Earth moved in an obliquely circular motion around “the fire” (interestingly, this is not a reference to the sun because Philolaus though the moon and sun moved around “the fire” as well.)

And then I get lost. Much like the work he was refuting, Ptolemy’s Almagest, equations, charts and graphs dominate the book. Then again, this book wasn’t written for me. It was written for mathematicians. For those of us unversed in the mechanics of astronomical configuration, we are simply left in awe of those disciplined enough to be so,

[Tyler · Rating 4 out of 5]

I don't really know exactly how I would go about reviewing this.

Lets start with the objective. The objective of this book is to delineate the orbital patterns, and different sorts of longitudinal positions, latitudinal positions, and additosubtractions arising out of the latitudinal positions that affect the longitudinal positions of the Earth, Moon, Sun, and five known planets (Mars, Jupiter, Saturn, Mercury, and Venus). These bodies were explained in a couple of different ways (typically with a heliocentric theory or a geocentric theory and sometimes with epicyclic orbits versus a typical circular orbit)

Copernicus was heavily influenced by Ptolemy as well, so concentric epicyclic orbits were certainly something utilized by Copernicus, in reference to Ptolemy.

The problem starts really in the mathematics. While I applaud the findings of this scientist and the others who helped him, I am particularly at ends with some of the ways he comes to conclusions. My particular translation had a ton of small clerical errors committed by the translators/editors, however this was a big problem for them too, because they could never really figure out how or why he got there, so they never fixed errors.

In addition, some of these errors TRANSLATED over the proofs, meaning that Copernicus was actually the one who made them! I noticed very many problems, including a problem almost towards the beginning, when Copernicus was utilizing Menelaus' theorems with spherical triangles. There was a problem with knowns and unknowns, which I'm sure that Euclid with his Data, would be shaking his head at.

I have to give this 4/5 stars, not because it's a bad book, but because it's an amazing one despite Copernicus not being the best mathematician.

[Rachel · Rating 4 out of 5]

show me deferent and i'll disprove your epicycle

[Cathy Garcia · Rating 5 out of 5]

I am a fan of Copernicus' work, enough said.

[The Esoteric Jungle · Rating 1 out of 5]

Copernicus was a neo-platonist occultist studying under Novara and merely republishing what we such have all, always, already known. such all encompassing notions of ours always will be contrary to the formatory, dead-weight fact, small minded aristotelian materialist majorities with noses to the ground. Hawking was king for a day among them and the last person who should have been given free reign to edit holy Copernicus - whom we owe so much true science to precisely because of his fight against the aristotelians in his day.

I had to put this book down after 30 pages into it, so much has been scrubbed out from what I have seen of earlier publications obtainable online. One has to realize Hawking is the type who flew half way around the world to go out of his way to belittle a Hindu teacher espousing his own nations teaching on sacred theism as it is understood in their own scriptures (a type so forlorn to western fundamentalist theism they are like night and day, but Hawking - being the control freak, reactionary westerner he is - had to go over and try to discredit him like a witch hunt).

I am no fluffy modern happy, happy new ager by a long stretch but I overheard my wife listening to Esther/Abraham Hicks Positivism stuff and she was saying how the scientific community is 100 times more formatory, derisive, negative, judgemental and dangerous than the worst fundamentalists and of all places she would put herself to grow emotionally positively that environment would be the last. I almost jumped up and down in joy someone was just saying it like it is.

Anyways, time for the earth to become neo-platonic occultists and objective to exponential degrees and leave the fundi and materialist witch hunters to themselves for a change. Peace out and keep learning (and find better, unedited, editions of things!).

[Paul Mamani · Rating 4 out of 5]

"On the Revolutions of the Heavenly Spheres" (De revolutionibus orbium coelestium)


By Nicolaus Copernicus is a seminal work in the history of astronomy. Published in 1543, it presents the heliocentric theory, which posits that the Earth and other planets revolve around the Sun, challenging the long-held geocentric model that placed the Earth at the center of the universe.




Copernicus' work laid the foundation for modern astronomy and significantly influenced scientific thought. His model provided a more coherent and integrated understanding of the cosmos, where planets move in elegant harmony around the Sun

Inti, Peru

[Lloyd Earickson · Rating 4 out of 5]

After my somewhat lackluster experience with Carnot’s On the Motive Power of Fire , I almost removed books like this one from my reading list.  In the case of Copernicus’ On the Revolutions of the Heavenly Spheres, I’m glad that I did not, because this brief text – practically a pamphlet – was fascinating on several levels: historically, culturally, mathematically, scientifically, and conceptually.  It also prompted yet another minor epiphany regarding how we teach and understand history, which we’ll be discussing at length in another post.

Beginning with letters of support for the work from prominent church leaders and including Copernicus’ own defense of his work, the reader is reminded that the idea of the Earth being mobile and not the center of the universe was not initially a source of enormous public controversy; it was a source of academic controversy, like an esoteric debate about whether loop quantum gravity or string theory better provide a quantum scale explanation of gravity.  We also learn that, like almost everything (apparently), the Greeks did it first – Copernicus cites several Greek thinkers who proposed that the Earth moved and was not the center of the universe, albeit overshadowed by Aristotle and his crystalline spheres, and later Ptolemy.  Still, none of them proposed quite the triplicate motion that Copernicus describes, and none of them presented it in a way that was as convincing as Copernicus’.

In fact, the greatest strength of Copernicus’ heliocentric model is its clarity and elegance.  He is not saying whether or not his model is reflective of reality, or trying to explain why the cosmos behave the way they do; he is simply proposing an alternative way of modeling the movement of the heavens that provides simpler and more accurate predictions than the Ptolemaic model with its epicycles and other contortions.  This is key, because in that sense the debate is all about reference frames.  Indeed, depending on how you define your reference frame, you could put the Earth at the center of the universe with everything else revolving around it, and you would still successfully describe reality – it would just be far, far more complicated than describing those motions with respect to a reference frame with the sun at the origin.  This is, then, a geometric argument, not a physics one.

No wonder, then, that Copernicus spends about half his text referencing Euclid’s Elements (and I’m glad that I read it before so that I could catch those references).  The first half of the text lays the groundwork and justification for his proposal, and the second half establishes the geometric proofs by which he determines, with remarkable accuracy, the motions of the planets.  With a basic grounding in geometry, I do not think you will struggle to understand his logic, even if you might not be able to replicate it.

That the sun lies at the center of the solar system with the planets moving about it and the whole arrangement determined by gravity seems obvious to us today, but that is because we are surrounding by depictions of the solar system in that configuration.  Don’t allow those preconceived notions to lead you to underestimate the significance of what Copernicus did with On the Revolutions of the Heavenly Spheres; in its way, it should be considered as paradigm-shifting as Einstein’s relativity, because it similarly forces readers to approach something commonplace from a completely different perspective, presenting as obvious something that no one before managed to connect.  I try to imagine looking up at the sky, and at tables of measurements taken painstakingly and with varying accuracy and precision over centuries, without any pre-existing image in my mind of the solar system’s arrangement, and I wonder if I could have had the imagination and perspective necessary to conclude that my own perspective should not be the origin of my calculations.

Yes, this piece is of particular interest to me, given my chosen profession, and doubtless that colors my opinion and experience with it.  That aside, it is a clearly written piece that offers excellent (and nuanced) incite into a form of scholarship that predates the rise of the scientific method (there is far greater emphasis on rationalist approached than empiricist, for all that empiricism plays a role, and aesthetics even come into play).  Not to mention its significance in the history of our understanding of the universe.  Without Copernicus, it can be argued that Newton, Kepler, and Galileo may never have made their own enormous contributions to astrodynamics.  By reading it, you can be a part of that history.  Even if you’re not the center of the solar system.

[S · Rating 5 out of 5]

torun, polska 19 feb 1473 - 1543 frauenburg, deutschland

1543
Amherst, NY: Prometheus Books, 1995
Charles Glenn Wallis, trans.


genius: gathered together the observations before him, and interpreted them in leaps of deduction (and mathematics); the method of genius simple; the leaps astronomical
GENIUS

[Whiskey Tango · Rating 3 out of 5]

And then came a voice out of Poland, saying that this earth, footstool of God, and home of his redeeming pilgrimage, was a minor satellite of a minor sun. It seemed so simple a thing to say. We cannot be moved to fear or wonder by it now. We take it for granted that the soil on which we stand is a passing thing, transiently compact of elements that will disintegrate and leave not a wrack behind. But to the medieval world, whose whole philosophy had rested on the neighborly nearness of the earth and God, the constant moral solicitude of the Deity for man, this new astronomy was an atheistic blasphemy, a ruthless blow that seemed to overthrow Jacob's Ladder which Faith had built between angels and men.

Copernicus' book "On the Revolutions of the Celestial Orbs" was well named, for no book in history has created a greater revolution. That pious Polish monk, sitting patiently before the baffling stars, had meant no harm. He had no suspicion of the bearings of his thoughts on the future of belief. He lost himself in the search for knowledge. He was sure that all truths must be good and beautiful and would make men free. And so by the magic of his mathematics, he transformed a geocentric and an anthropocentric universe-a world that revolved about the earth and man-- into a kaleidoscope of planets and stars in which the earth seemed but a moment's precipitation of floating nebula. Everything was changed-distances, significances, destinies. And God, who had seemed to inhabit the friendly and flowing clouds, disappeared into the far reaches of illimitable space. It was as if the wall of a man's house had been torn down by some blind and angry wind, leaving him ill-sheltered in the darkness of infinity.

With Copernicus modernity begins. With him secularism begins. With him, reason makes its French Revolution against the faith immemorially enthroned and man commences his long effort to rebuild with thought the shattered palace of his dreams. Heaven becomes mere sky and space and nothingness, who once had hoped for paradise. It was as in the fable Plato told, of the gods would care for a man until he had come of age, and then disappeared, leaving him to the devices of his own intelligence. It was as in the ancient savage days, the old man of the tribe drove the young men forth and they then seek some other soils to raise upon at their own homes their own happiness. With the Copernican revolution, humans were compelled to become of age.

[Christopher Byram · Rating 3 out of 5]

I first discovered this book when it was referenced on Khan Academy, in the article 'READ: Nicolaus Copernicus', in Unit 5, in the course 'World History Project - Origins to the Present'. The article states that, by 1532, the author had mostly completed a detailed astronomical manuscript he had been working on for 16 years. He had resisted publishing it for fear of the ensuing controversy and out of hope for more data. Finally, in 1541, the 68-year-old author agreed to publication, supported by a mathematician friend, Georg Rheticus, a professor at the University of Wittenberg, in Germany. Rheticus had traveled to Warmia to work with the author, and then took his manuscript to a printer in Nuremberg, Johannes Petreius, who was known for publishing books on science and mathematics. The author gave his master work the Latin title 'De Revolutionibus Orbium Coelestium' (translated to English as the title of this book).

In this book, the author begins by describing the shape of the Universe. He provides a diagram to help the reader. In the diagram he shows the outer circle that contains all the fixed stars, much further away than previously believed. Inside the fixed stars are Saturn, then Jupiter and Mars, then Earth, Venus, and Mercury, all in circular orbits around the Sun in the center.

He calculates the time required for each planet to complete its orbit and is off by only a bit. The author's theory can be summarized like this:

1. The center of the Earth is not the center of the Universe, only of Earth’s gravity and of the lunar sphere.
2. The Sun is fixed and all other spheres revolve around the Sun. Copernicus retained the idea of spheres and of perfectly circular orbits. In fact, the orbits are elliptical, which the German astronomer Johannes Kepler demonstrated in 1609.
3. Earth has more than one motion, turning on its axis and moving in a spherical orbit around the sun.
4. The stars are fixed but appear to move because of the Earth’s motion.

[Mindo'ermatter · Rating 2 out of 5]

Key Exerpts from Complete Work

Information provided in this incomplete presentation includes those of greater interest and probability the most revolutionary at the time. The preliminary sections provide historical context. The translation is generally easy to understand. The original work comprised six books within one volume, while this edition has portions of two.

There are at least three possible explanations for the missing information: (a) the publisher had an incomplete original, (b) the photocopying was poorly done, or (c) the most significant parts were excerpted for simplicity or for a specific course of study.

Although the book description correctly states the length at 56 pages, the abrupt ending of the text mid chapter without explanation was disappointing and misleading.

Recommend that "About this book" information be updated to be more transparent about what is actually included.

Some basic understanding of geometry will help with more technical sections; however, they key elements of his famous heliocentric theory is well represented without needing too much math background.

The included diagrams a expandable in the Kindle version, allowing closer scrutiny.

In its current format, this version is appropriate for those wanting an English introduction to the theory's early publication.

[Alp Turgut · Rating 3 out of 5]

Nicolaus Copernicus’in "On the Revolutions of the Celestial Spheres / Göksel Kürelerin Devinimleri Üzerine"yi iki farklı açıdan incelemekte fayda var. İlk kitabın büyük bir kısmı ve sonraki beş kitabın giriş yazıları dışında okuyucuya zengin bir okuma sunamayan eserin tamamen teknik bir eser olması ne yazık ki eseri edebi açıdan yüksek yerlere yerleştiremiyor. Fakat, bilimsel açıdan bakıldığında Dünya merkezli sistemi Güneş Sistemi’ne taşıyarak insanlığa duyurması sebebiyle devrim niteliğinde bir eser olduğuna kuşku yok. Dünya’nın ve diğer gezegenlerin küre şeklinde olmasından bir yılın 365 gün 6 saat olmasına kadar tüm bilgileri antik zamanlardan 1500’lerin başına taşıyan ve bunları matematiksel bir şekilde açıklamaya çalışan ünlü matematikçinin tüm karamalarını inceleme şansı buluyorsunuz. Kısaca, okudukça Copernicus’in gözlem yeteneğine ve zekasına hayran kalmamak elde değil. Bu yüzden, oldukça değerli bir eser olan "Göksel Kürelerin Devinimleri Üzerine", Cengiz Çevik’in başarılı çevirisiyle her kütüphanede bulunması gereken eserlerden.

24.08.2018
İstanbul, Türkiye

Alp Turgut

http://www.filmdoktoru.com/kitap-labo...

[Justyna · Rating 5 out of 5]

No dobra Panie Kopernik, tu psychofanka😀 Jako ze z fizyki ledwo przedlam, ale uwielbiam sci fi (i Kopernika) doszlam do wniosku, ze najlepszym sposobem, zeby po 37 latach zycia zrozumiec o co dokladnie chodzi z teoria Kopernika, jest.. przeczytanie jego kiazki. Balam sie, ze nic nie zrozumiem. I nie bede klamac, nie zrozumialam wszystkiego, ale zrozumialam wystarczajaco, by sie zachwycic!

Nigdy wczesniej nie czytalam tak skomplikowanej i jednoczesnie prosto napisanej ksiazki! Kazde zdanie jest trudne i kazde poddajesz analizie. Jezyk tez nie ulatwia. Mikolaj, wlasciwa sobie zwiezloscia, nie zawarl ani jednego slowa, ktore bylo niepotrzebne lub mialoby ubarwiac opowiesc. Krotko, ciasno, konkretnie. Zadaje sobie teraz mase pytan i tak, dalej nie rozumiem jak prosty acz uczony czlowiek z epoki renesansu (choc w Polsce to raczej bylismy w sredniowieczu) dokonal wyliczen na poziomie, do ktorego dzis wielu z nas nie dorasta.
Moim zdaniem, lektura obowiazkowa. Wraz ze wstepem dla papieza, aby zrozumiec czasy, w jakich Mikolaj zyl.
Az strach pomyslec co by sie stalo, gdyby tej ksiazki nigdy nie wydal.

Ps. Zauwazam, ze okreslenie wschody i zachody slonca nie jest do konca akuratne, ale za to brzmi ladnie. Pewnie to zaszlosc z czasow przedkoperikanskich.

[Richard Legault · Rating 5 out of 5]

Nobody should end their days on planet Earth without first having read a version of this book at least once. This is the book most often credited as causing the end of the Middle Ages by triggering what many have called the greatest scientific revolution in history. High praise indeed for the work of a Polish priest, educated in the medieval system of Abbey and Cathedral schools.

My rating is for a different version I read packaged into Stephen Hawking's 'On the Shoulders of Giants.' Hawking's introductory essay is very insightful too.

It is also insightful to remember that the book is addressed to an audience also educated by the same system of church run schools. The educational back-story that enabled the writing of this book and that also prepared the audience to receive it, may even be better than the book itself. When it comes to the re-birth ('renaissance', in French) of science was the Church really the wannabe strangler or was she really the mid-wife?

But that's a different story and a different book.

[Marcos Augusto · Rating 4 out of 5]

Nicolaus Copernicus, was a Polish astronomer who proposed that the planets have the Sun as the fixed point to which their motions are to be referred; that Earth is a planet which, besides orbiting the Sun annually, also turns once daily on its own axis; and that very slow long-term changes in the direction of this axis account for the precession of the equinoxes. This representation of the heavens is usually called the heliocentric, or “Sun-centred,” system—derived from the Greek helios, meaning “Sun.” Copernicus’s theory had important consequences for later thinkers of the Scientific Revolution, including such major figures as Galileo, Kepler, Descartes, and Newton. Copernicus probably hit upon his main idea sometime between 1508 and 1514, and during those years he wrote a manuscript usually called the Commentariolus (“Little Commentary”). However, the book that contains the final version of his theory, De revolutionibus orbium coelestium libri vi (“Six Books Concerning the Revolutions of the Heavenly Orbs”), did not appear in print until 1543, the year of his death.

[Raquel Pedro · Rating 4 out of 5]

Lido apenas a introdução e o primeiro livro. (até pág.103).
De facto, um trabalho exímio para a altura que não só reconhece a área de estudo (astronomia) como a define desenvolvendo conceito próprio de "hipótese". A observação como primeiro passo metodológico fundamental. No primeiro livro além da declaração de intenções e de uma série de escritos gerias introdutórios no qual são também referenciados outros estudiosos relevantes (Ptolomeo, Plutarco, Euclides) também aborda as posições das esferas e movimentos da Terra assim como a constituição geral do universo. Uma série de considerações improtantíssimas ainda nos dias que correm e muitas vezes revolucionárias à época, uma leitura que serve também a quem se dedica aos estudos humanísticos e culturais.

[El Bibliófilo · Rating 4 out of 5]

My comments in video: https://youtu.be/wlcRRY5eAt0

Mis reflexiones.
Luego de la lectura de "Carta a Cristina de Lorena" de Galileo Galilei, me decidí a leer la obra de Copérnico de la misma colección, para conocer de primera mano la obra mencionada por el científico.
A pesar de ser una lectura bastante técnica, me gustó encontrar argumentos que respaldaban la intuición que compartí con ustedes en la obra de Galileo: que la actividad humana es principalmente político-religiosa, y la ciencia también.
Los invito a comentar sobre las reflexiones que comparto, dejándonos llevar por el diletantismo erudito que propongo.

[Jonathan Jerden · Rating 5 out of 5]

A 20-hour master class on our solar system, using extensive geometry including line segments, arcs, angles, spheres & ellipses of Euclid's Elements to define the rotation - on it's axis & around the sun - of the six known plants when he wrote this, his seminal work, in 1543.

If you read Euclid's Elements before hand, as I did coincidentally just a few months ago, the reasoning of Polish-born Copernicus flows much easier.

[Porter · Rating 3 out of 5]

This is a very tough read. I am not sure how much of it has to do with the subject matter vs a poor translation. It’s definitely interesting how Copernicus used geometry to try to explain so many aspects of cosmic motion. A lot of it is difficult to follow or verify yourself though.

[Regalia Lenzi · Rating 4 out of 5]

Mam wrażenie, że książka jest okrojona. Że brak jej tabel, rysunków, a może i niektórych tekstów. Czy mówię prawdę - oj chciałabym wiedzieć, bo ciężko stwierdzić, czy oryginalne "O obrotach..." też składało się na te kilkanaście stron.

[Carl Koontz · Rating 5 out of 5]

You can feel his fear of the devil worshipping christians in the beginning. His use of logic is just awesome.

[Julia P]

I read the first book of the 6 online and couldn't find the rest. While this is a great book, it isn't a classic in my opinion as a book that every person should read.

[Wojtek Konieczny · Rating 5 out of 5]

10/10. Doniosłość tego dzieła nie podlega dyskusji, ale! Jak to jest cudownie napisane!!!

[Carrick · Rating 4 out of 5]

Copernicus' original treatise