The background of this book about the movement of celestial bodies.
In the Copernican era, Ptolemy's geocentric theory was dominant in Europe. Ptolemy could not feel the rotation of the earth, but only felt that the sun rose in the east and set in the west every day. It's like when people are driving on a big ship, they often don't feel the ship moving, but only see things on the shore going backwards. In the middle ages, the church deified the geocentric theory and used it as the basis to prove the existence of God.
In the 15 and 16 centuries, due to the development of navigation, it was necessary to accurately determine the coordinates of ships, which greatly promoted the observation of astronomical phenomena. With the accumulation of astronomical data, people put forward a series of new topics that ptolemaic system could not answer. The development of practice requires a major reform in astronomy. Copernicus was born in this period.
1March 47319th, Mikolaj Copernic was born in a merchant's family in Torun-sur-Vistula. He lost his father at the age of ten and was raised by his knowledgeable and cheerful bishop uncle. Under the influence of his uncle, Copernicus loved natural science from an early age. 149 1 year, Copernicus entered the University of Cracow. This university was famous in Europe for astronomy and mathematics at that time. In this school, although Copernicus obtained a medical degree, he became interested in astronomy, spent a lot of time reading astronomy and mathematics, studying theory and practical astronomy, and learned to use astronomical instruments for observation.
1496, Copernicus went to Italy to study, where he received his doctorate. During this period, he met Novara, a famous astronomer, and they often observed celestial bodies together and discussed issues related to astronomy. Novara once criticized ptolemaic system for being too complicated to conform to the harmony of mathematics. They discussed the mistakes in Ptolemy's maxim and the possibility of improving ptolemaic system, which inspired Copernicus to devote himself to the reform of astronomy.
1503, Copernicus returned to Poland from Italy as a priest. He works as a doctor in the parish and serves the poor enthusiastically. He also used the bell tower of the church to build his own earth water tower, and sent water to the poor families through pipelines. Because he did many good things for the poor, the local people later set up a monument to commemorate him. During his work as a priest, he also devoted a lot of energy to astronomical research and observation. He built a small astronomical observatory by using the watchtower of the church wall, and made some observation instruments, such as Shibungi, trigonometry and astrolabe, and made a lot of observations and calculations. His calculations are particularly accurate. For example, the time of the sidereal year he got was 365 days, 6 hours, 9 minutes and 40 seconds, and the error was one in a million. The average distance from the moon to the earth he got was 60.3 times that of radius of the earth, and compared with the modern value of 60.27, the error was only five ten thousandths! After 30 years of unremitting efforts, Copernicus finally completed his theory system of celestial bodies and wrote an epoch-making masterpiece, The Theory of Celestial Bodies.
Copernicus was a rigorous man. In fact, the first draft of the Theory of the Operation of Celestial Bodies was written as early as 15 12. In the next 30 years, he has been constantly observing and analyzing, and finally carefully three drafts. 1543 On May 24th, Copernicus received the newly printed first edition of "On the Operation of Celestial Bodies" on his deathbed. He got his wish, touched it with his hand and died.
The 1 edition of "On the Operation of Celestial Bodies" was arbitrarily abridged by the publisher Ossie Ander, and almost every side was different from the original manuscript, and a false preface was added, claiming that the book only provided a calculation tool and did not offend the Bible or the reality of nature. This behavior was condemned by Copernicus' students and friends at that time, and they planned to get rid of the false preface and republish it as it is. Unfortunately, the manuscript was lost. After more than 300 years of oblivion, most of the manuscripts were discovered and reprinted in 1873, and some of the lost and abridged contents were not supplemented until the fourth edition of 1953 "On the Operation of Celestial Bodies".
Looking for the beauty created by the creator
And orderly cosmic institutions.
Copernicus was not an innovator who wanted to overthrow all traditional astronomical concepts, but a man with truly pure orthodox beliefs. Ptolemy's geocentric theory has been used to describe the motion of celestial bodies since the 2nd century BC. Ptolemy's main work is called Selected Astronomies, with a volume of *** 13. Its main content is that the earth is the center of the universe and stands still, while the sun, moon and stars move around it. Ptolemy had to admit the rationality of the earth movement thought put forward by some people at that time: "From the phenomena of the starry sky and the universe, there is nothing to object to the simplicity of this thought." However, he criticized the theory of earth motion with his so-called "mechanical principle": "Assuming that the earth moves with all other creatures, it is obvious that because of its great weight, it must surpass the front of other heavy objects, throw all creatures into the air with other unsupported heavy objects, and finally it will fall from the sky quickly." Ptolemy set out from Aristotle's rigid dogma that "everything tends to the center", fixed the earth as the center of the universe and explained it systematically. Ptolemy adopted apollonius's current wheel system and even wheel system, and also adopted the concepts of eccentric circle and equidistant eccentric point of Imba Valley, which showed the movement of planets on the celestial sphere. Ptolemy believes that the five planets, the sun, the moon and the earth, all run in eccentric circular orbits, and each planet has its own orbital height. (as shown in figure 4- 1)
Figure 4- 1 schematic diagram of Ptolemaic geocentric system In the seven orbital layers in the figure, the sun and the moon directly revolve around the earth. The five planets, water, gold, fire, wood and earth, all have their own "current round" orbits, and the centers of these five rounds all revolve around the earth according to their respective orbits. The orbit of the center of this wheel is called "even wheel". Ptolemy's model just demonstrates the Christian doctrine that God created man on the sixth day and man occupies a prominent central position in the universe, that is, the center of the universe. But this is an extremely complicated system.
From the standpoint of scholasticism, this extremely complicated system obviously deviates from Aristotle's physical system, which is regarded as a classic and cannot be violated. In that system, the cosmic system is described as a concentric ball. Copernicus hoped to solve this contradiction in a new way. With sincere orthodox faith, he began his exploration, questioning and criticizing the old theory, which could not always follow certain principles, and therefore could not infer the shape of the universe and the eternal symmetry of its parts. He believes that the observable world should be a symbol of God's will. Finding symmetry and order behind seemingly complicated phenomena is a proof of God's will and a respect for God. In the preface of the Theory of Celestial Motion, he wrote: "After thinking about the suspicious part of traditional mathematics in studying celestial motion for a long time, I am angry that philosophers can't put forward the correct theory about the beautiful and orderly cosmic mechanism created by the creator for us ..." In order to find a solution to this contradiction, "I took pains to reread the philosophical works I can get to see if there are any hypotheses different from mathematicians in celestial motion. It turns out that in Cicero's works, Hersitas' description of the earth's movement is realistic. Later, in Pu Rutar's works, I saw that others agreed with similar views ... which inspired me to start thinking about the earth's movement. "
heliocentric theory
The theory of celestial movement is divided into six volumes. The first volume briefly introduces Heliocentrism's basic viewpoints, which is the general outline of the book. This paper discusses the movement of the earth, the orbital position of the planet and the overall structure of the universe, demonstrates why the earth is also a planet, explains the reasons for the four-season cycle, and answers various accusations against the theory of ground motion. The second volume introduces the mathematical principles and explains the apparent motion of celestial bodies with spherics. The third volume discusses the movement of the earth around the sun. The fourth volume discusses the movement of the moon around the earth. The fifth volume discusses the motions of the five planets, focusing on how the motion of the earth affects the apparent motions of the planets in the meridional direction, and how to make all these phenomena have accurate and inevitable laws. The sixth volume continues to discuss planetary motion, focusing on "considering the motions that cause the planets to deviate in the latitude direction, showing how the earth motion dominates these phenomena, and determining the laws they follow in this field."
Copernicus' dialectical methodology: Copernicus' thinking on "the movement of the earth" or "the movement of the sky" is witty and dialectical. He believes that the obvious inhomogeneity of the movements of various celestial bodies is due to the fact that the earth is not at the center of their movements, but at a distance from the center of the universe. Therefore, "first of all, we should carefully study the position of the earth in the sky, so as not to put the cart before the horse and mistakenly regard the phenomenon caused by the earth's movement as the result of celestial movement." He pointed out, "If the sky is not hypothetical, but the earth turns from west to east, then all serious thinkers will find our conclusion correct. The sky contains everything. Why should we attribute sports to inclusiveness, not inclusiveness? " According to the fact that "the sky is getting bigger and bigger, it is extremely huge", he said: "In fact, it would be strange if the extremely huge universe, rather than a small part of it-the earth, rotates once every 24 hours." He quoted the famous sentence in Virgil's epic "We sail forward from the port, and the land and the city retreat" as a metaphor, and asked: "Why can't we recognize the completely natural movement of the earth and adapt to its own shape, but we need to assume that the whole universe (the limit of which is unknown and impossible to know) is rotating?" He thus asserted: "The earth is certainly not the center of the planetary orbit. And it can be said that the earth has another movement besides Sunday rotation. " These paragraphs contain the view of relative motion. Obviously, Copernicus has realized that the movement is well-founded.
Copernicus pointed out that ptolemaic system was complicated because he imposed three movements of the earth (rotation, revolution and rotation of the earth's axis) on every celestial body, which added three circles to each celestial body and artificially complicated the cosmic system, so that there were 80 circles in the ptolemaic system. This makes some very smart people feel dizzy. In Chapter 11 of Volume I of "On the Operation of Celestial Bodies", Copernicus specified three movements of the earth. The first one is "the earth rotates around its axis day and night from west to east". Because of this movement, the whole universe seems to move in the opposite direction along the "regression circle"; The second is "the center of the earth runs from west to east on the ecliptic between the orbits of Venus and Mars with the annual rotation of all celestial bodies on the earth". Because of this movement, the sun seems to move in a similar way on the ecliptic; The third is "slope motion", that is, the motion of equatorial plane or rotation axis relative to the heliocentric line. Because of its combination with the second motion, the direction of the rotation axis relative to the celestial sphere of the star remains unchanged. This joint movement is now called the revolution of the earth. Copernicus believes that in order to establish a system in which the earth is at rest in the center of the universe, the ancients added three kinds of movements of the earth to every celestial body, making their cosmic system unnecessarily complicated. According to the three major movements of the earth and the inherent movements of celestial bodies, Copernicus simply and uniformly explained the diurnal movements of celestial bodies observed from the ground, the speed changes of the sun and the moon, the retrograde, stagnation and north-south movements of planets, and the precession of the vernal equinox. This is a revolution in the way of thinking.
After Copernicus reversed the main body of rotation, he said confidently: "So, starting from the hypothesis of the earth's motion, after long-term repeated observation, I finally found that if the motions of other planets are considered together with the earth's motion and calculated according to the orbital ratio of each planet, then not only will all kinds of observation phenomena be obtained, but also all the star orbits will be organically related to the size and order of the celestial sphere and the vault itself. In this way, Copernicus put forward the general arrangement of his solar system structure: farthest.
The fixed celestial sphere of the star constitutes the reference background for the position and movement of other celestial bodies; Then from far to near, Saturn, Jupiter, Mars, Earth, Venus and Mercury all draw concentric orbits around the sun. "The central is the sun. In this magnificent palace, can we put this luminous body in a better position to illuminate everything at the same time? The sun is called the lamp of the universe, the heart of the universe and the master of the universe. ..... The sun seems to be a family of planets sitting on a throne, ruling around it. " (Figure 4-2)
The moon is a satellite of the earth. Copernicus believed that all planets, including the earth, revolve around the center of the sun. Only the moon orbits the earth with the earth as the center. He said, "We can't separate the moon from the earth". Copernicus pointed out that the earth goes around the sun along a certain orbit with the moon between the orbits of other planets. So Copernicus called the moon the "guardian" or "follower" of the earth. Later, it evolved into a "satellite" and has been in use ever since.
About "Atoms" In the first volume of "On the Operation of Celestial Bodies", there is a discussion about atoms, which was only added by 1953. Copernicus pointed out that "the so-called atom is the smallest particle that can no longer be divided." They overlap or multiply together, but because they are invisible, they will not immediately form visible objects, but their number can be increased to this extent, enough to accumulate to a visible size. " This is one of the few precious expositions about the existence of atoms and their relationship with macro-matter before the emergence of modern atomic and molecular theory.
On gravity Copernicus emphasized in his masterpiece, "I personally think that gravity is just a natural will injected by the divine creator in various parts, combining them into a unified sphere. We can assume that the sun, the moon and other bright planets have this power, and they all remain spherical under its action. " This is undoubtedly an important inspiration for Newton to establish the law of universal gravitation and study the dynamics of the universe.
Scientific and Cultural Significance of the Theory of Celestial Movement
The publication of The Operation of Celestial Bodies caused an uproar. On the one hand, Copernicus' Heliocentrism and Ptolemy's geocentric theory waged a long struggle. This is not only an academic dispute, but also a struggle between science and theology, materialism and idealism, dialectics and metaphysics, and two cognitive routes. Many great scientists gave their lives to defend the truth: Bruno was burned to death in the Rome Flower Square; Galileo was sentenced to life imprisonment by the inquisition. However, the development of modern astronomy not only proved Heliocentrism's victory in geocentric theory, but also surpassed Copernicus' theory. But all these advances began with Copernicus. Copernicus' thought about the earth movement is an epoch-making great scientific achievement, and its great revolutionary role in science and ideology and culture is as follows:
First of all, Copernicus moved the center of the reference system for scientific understanding of celestial motion from the earth to the sun, thus taking the most difficult and important step in modern cosmology research. L infeld commented on Copernicus' achievements like this: "Now we can browse the universe from a distance. We can not only move ideologically from the earth to the sun, but also from the sun to the stars, from the stars to the center of our galaxy and from our galaxy to distant nebulae. ... the first step is the most difficult, and this first step was completed by Copernicus. "
Secondly, Copernicus' thought that the rotation motion is the "inherent property" of celestial bodies was revolutionary at that time. In Ptolemy's system, various celestial bodies, such as "the original moving sky" and "the highest sky", were not only created by the creator, but also promoted by angels. But in Copernicus' system, the motion of celestial bodies is its inherent nature, and "the original moving sky" and "the highest sky" are only a static reference for calculating motion. This is the pioneer of Newton's later absolute space hypothesis.
Thirdly, as the basic starting point of constructing Copernicus' theoretical system, the concept of relative motion has an important turning point in epistemology and methodology. Copernicus pointed out that "every observed position change may be caused by the movement of the observed object or observer, and of course it may also be caused by the inconsistency between the two movements." When an object moves in the same direction at the same speed, this movement is imperceptible. I mean that the motion between the measured object and the observer is imperceptible. It is from the earth that we see the ballet of heaven repeating itself before our eyes. Therefore, if the earth has any kind of movement, it seems to us that all objects outside the earth will have the same movement, but in the opposite direction, as if they are crossing the earth. Sunday's rotation is such a movement, because it seems that the whole universe participates in this movement except the earth. Copernicus also used a popular and vivid metaphor to say: "When the ship runs quietly, the crew can see the reflection of the ship's movement from everything outside, but on the other hand, they can imagine that they and everything on board are stationary. Similarly, the movement of the earth will undoubtedly create the impression that the whole universe is rotating. "This is the clearest scientific exposition on relative motion put forward by Galileo before, a sharp weapon to criticize theological dogma, and also the key to open human scientific understanding. For thousands of years, people have become accustomed to the phenomenon that the sun, the moon and the stars rise and set in the west, and Ptolemy's explanation is just in line with people's common sense. But Copernicus' profound thinking on this seemingly true common sense tells us that common sense may also be wrong. Science is not equal to common sense. If you cast a curious glance at what you take for granted and make a scientific analysis, you may find the truth of science.
Fourthly, Copernicus's "Heliocentrism" not only "opened the question of planetary motion, but also promoted the combination of two sciences and even two methods in the next 150 years". That is to say, although people often think that Newton's law of universal gravitation combines the motion on the ground with the motion in the sky, in fact, this process started from Copernicus.
Fifth, Ptolemy's system endows people living on the earth with a unique position, thinking that human beings are the sum and peak of all things, as if everything was born for human beings to enjoy or submit to. On the other hand, Heliocentrism of Copernicus "liberated human beings from the state of self-centeredness." With ptolemaic system, we abolished blind self-confidence.
Sixth, the theory of celestial bodies declared the independence of natural science. Engels said in Dialectics of Nature, "Since then, natural science has been liberated from theology ... Since then, the development of science has made great progress and gained a kind of power, which can be said to be proportional to the square of the distance from its starting point. It seems to prove to the world that from now on, the highest product of organic matter, that is, the human spirit, is a law of motion just opposite to inorganic matter. " Of course, if we look at Copernicus' theory with modern scientific theory, we will find that there are still many mistakes, but after all, we should not criticize our predecessors, but should inherit the scientific skepticism and the spirit of fighting for truth shown by Copernicus and his defenders and martyrs.