Analysis:
First, the stage of ancient simple cosmology
In ancient times, intuitionism gave people the impression that the earth was bigger than the "stars", which ruled out the possibility that the earth revolved around them without thinking.
In 600 BC, a group of so-called thinkers appeared in ancient Greece. They were "full and full" and began to think about the relationship between human beings and the universe, challenging traditional ideas. Especially represented by Pythagoras school, they put forward that the earth is a circle and is in motion. In 500 BC, a man named Anaquel Anaxagoras put forward a conclusion that belittled the status of the earth: the mass of the sun is much greater than that of the earth, and the earth revolves around the sun, not the other way around.
Second, the geocentric stage
Eudoxus Sphere Model: In order to improve the status of the earth again, eudoxus (? -347B。 C) A transparent concentric sphere array model centered on the earth is proposed. In this model, the earth is regarded as the center of everything, and all the stars move around their axes on their respective spheres. From the inside out are balls belonging to the moon, the sun, Mars, Jupiter and Saturn. The outermost ball surrounds all the balls. It carries the stars of all constellations, rotates around a specific axis, and has an angle with the axes of other spheres.
Defects of eudoxus sphere model: unable to explain comet phenomenon, unable to accurately predict solar eclipse, unable to explain retrograde planets; Why does the sun swing between the Tropic of Cancer? Why are there four seasons? Why are some constellations (such as Orion) visible in winter and some in summer?
However, this model is obtained by Aristotle (384B. C-322b。 C) It has a high academic and political status, so it gained popularity, became an official view and became an authority in the next 500 years.
Comments: science should not have personal prejudice, everything should proceed from reality, and learning should not be emotional; Authority is empty, and what conforms to objective reality is truth. (you can't deny authority because of this)
Ptolemy's geocentric theory;
This model initially has the characteristics of the theory of the universe.
"It may not be difficult to establish a geometric model of the movement of the universe, but it is much more difficult to upgrade the model to theory. A theory should be consistent not only with known observations, but also with future observations. Theory must be predictive, and it is necessary to predict the future on the basis of summing up and summarizing the past. "
Mathematical concept: plane: cycloid hypocycloid
Perimeter: Epicycloid, Epicycloid and Epicycloid
Current: A circle is rotating, and at the same time its center moves in a circle along a larger circle, and the trajectory drawn by a point on the circumference of the rotating circle.
Claudius Ptolemy found that eudoxus's model can improve its prediction ability by increasing the current wheel with appropriate size and adjusting the rotation speed, so that it is consistent with the observed data. In this way, a new geocentric model is obtained. Ptolemy therefore constantly revised eudoxus's model, supplemented and adjusted it. There is this round plus this round and this round sets this round. Finally, by adjusting more than 40 parameters, the new model is consistent with all the astronomical phenomena that can be observed at that time.
It can be said that Ptolemy's application in mathematics is very successful, and the prediction of the positions of stars, planets and the moon at any time is accurate. He introduced his geocentric theory with a 13 volume masterpiece "Mathematics Collection". After it was spread to Europe, it was renamed Astronomical Masterpieces.
The sorrow of science:
After the ninth century, astronomical masterpieces and many works by Aristotle were introduced into European monasteries. Thomas Aquinas, a friar of Dogo Church in 1273, accepted the view that the earth is the center of the universe, demonstrated most of the teachings with Aristotle's philosophy, and completed an outstanding masterpiece, The Encyclopedia of Theology. The Vatican accepted Aquinas' view and took his theory as the official theory.
1233 The Inquisition established by Pope Gregory IX became the chief culprit to prevent the further development of science. That in the next 300 years, science stopped.
"Science is based on ignorance. Only when unsolved problems are discovered can science flourish recklessly. If a society or a religion claims that all problems have been solved, science will lose its momentum of development. "
Comments: Doubt is the essence of science, and challenge is the driving force of science.
Third, the Heliocentrism stage.
Occam's razor: If there are several contradictory theoretical explanations for a set of observations, then the best explanation is the one that requires the least independent hypothesis.
British priest and philosopher ockham put forward this principle in 1340. It should be noted that the goal here is "best" rather than truth, but the phenomenon that is explained the most with the least theory is the "best" explanation.
People walking on the blade:
/kloc-Copernic, a polish priest and astronomer in the 6th century, proposed a Heliocentrism with only 15 parameters, which can also explain all astronomical phenomena. In order not to offend the church, he carefully pointed out that Heliocentrism was not the truth, but a simple algorithm for calculating planetary motion in the geocentric theory. Even so, the publication of his paper "The Theory of Celestial Motion" was delayed for thirteen years until 1543, when he died.
Johannes kepler (157 1- 1630) is a devout Christian and an outstanding computational mathematician. Religious belief drives him to explore the creator's creation, thinking that God is brilliant and the created universe is simple and beautiful. His knowledge of computational mathematics enabled him to discover unknown mysteries. In contrast, he was more optimistic about Ptolemy's model than Copernicus's. But to build a model of the universe, there must be a lot of observation data, which one person can't do. Compared with the universe, human life is too short.
So in 1600, Kepler visited Tycho Brahe (1546- 160 1), a rich and eccentric astronomer. Tycho observed the universe for 30 years and recorded a lot of accurate data. He also hopes to create his own model of the universe. But his own mathematical ability is not competent for this important task, and Kepler's mathematical talent can just make up for his shortcomings. However, what should have been a pleasant cooperation has become very unpleasant because of personality differences. Tycho died the next year, which made Kepler get a lot of data. He followed Tycho's model (five planets revolve around the sun and the sun revolves around the earth). When calculating the position of Mars, there is always an 8-point difference, but he completely trusts Tycho's data. Kepler said, "Because of this eighth difference, I created my own universe."
Comments: Accurate data is the basis of trust; The generosity of trust created the universe.
So Kepler returned to Copernicus' model and made complicated mathematical calculations. In 1609, he gave a conclusion:
Kepler's law 1: The orbit of each planet is an ellipse, and the sun is located at a focal point of the ellipse.
This law reveals the positional relationship between the planet and the sun. Kepler uses two parameters: the long semi-axis A and the eccentricity E to describe the shape of an ellipse. And calculate the orbit of mars. But what does the position of the planet have to do with time? So he found that the speed of the planet was unstable, thus denying Ptolemy's model; At the same time, it is found that the speed of perihelion is higher than that of apohelion, and the results show that the ratio of speed is inversely proportional to the ratio of distance. What about other positions? Soon he found that if the product of the speed of these two special points and the distance from the sun is certain, what about the other points? So 1609 gives another conclusion:
Kepler's Law 2: In the same unit time, the connection between the sun and the planet sweeps a certain area.
Even today, it is very difficult to calculate the area of a sector in an ellipse. In the era without calculus, Kepler's job is to draw a grid constantly, and use the area of the grid to approach the real value, so that its error reaches the limit of naked eye resolution. These two laws completely establish a model of the solar system, which has 16 parameters: eccentricity of six orbits, long semi-axis (astronomical unit) of five orbits, and speed of specific reference points on five orbits.
Is there any rule that can determine the relationship between track size and speed? If it exists, the parameters of the model can be further reduced. 16 19 Kepler gave a "law of harmony":
Kepler's Law 3: The cube of the semi-major axis of an orbit is directly proportional to the square of the orbital period.
According to this law, the average speed of the track can be calculated, and the speed of a reference point can be obtained, and the 16 parameters can be simplified to 1 1 reference points.
Galileo galilei (1564- 1642) lived in Italy, where the church rule was the most severe. 1590 completed a series of exercise experiments in Pisa University, which overthrew some viewpoints of Aristotle. /kloc-around 0/609, Galileo made his own astronomical telescope and discovered Jupiter and its moons. Confirmed some of Kepler's views.
Four, Newton's physical world (omitted)