Aristotle's (wrong) view: it is proposed that the motion of an object needs force to maintain, and the motion of the object will stop if it is not forced.
The positive significance of the wrong view: it is proposed that exercise is related to force; The heavier the object, the greater the falling speed should be; The earth is the center of the universe, and the sun, planets and moon should all revolve around it.
Ptolemy said one by one (the earth is absolutely stationary, and all movements are relative to the earth. Geocentric coincidence
The requirement of church rule is touted and affirmed by religion. )
Heliocentrism Bruno (1548— 1600) was arrested on 1592 for propagating Heliocentrism, and died heroically in the Flower Square in Rome.
Tycho and Kepler
German astronomer Kepler (157 1? 0? 1? 0? 1? 0? 1 1630) is a student and assistant of tycho. He studied the difference between Tycho's observation data on Mars and his theoretical calculation by 8 points, and later published Kepler's three laws.
Galileo, founder of kinematics. Main contributions:
Doubt (Aristotle's point of view): If the light object M falls more slowly than the object M, what about tying M and M together with a rope?
"Dilution of gravity thought", one slope theory: In order to study the situation of falling objects, Galileo designed a famous slope experiment to "dilute gravity", prolong the landing time and facilitate observation.
It refutes Aristotle's view that if small balls of the same size and different weights start falling at the same time, the heavy ball should land before the light ball. That is, the "law of falling body" was put forward.
Galileo also confirmed the law of inertia through inclined plane experiments (extrapolation and idealization).
Galileo's third great contribution was to put forward the principle of relativity. This principle is one of the most important cornerstones of physics. It is used in classical mechanics and Einstein's theory of relativity.
He was the first scientist who made great achievements in observing celestial bodies with a telescope. He confirmed Copernicus's "earthquake" with experiments.
Said ",completely denied Aristotle and Ptolemy's" celestial theory "(geocentric universe, geocentric).
It is pointed out that the falling body motion is also uniform acceleration motion.
Galileo s research thinking method;
The experimental method is successfully combined with the mathematical method. We don't simply do experiments, but proceed from a clear physical idea, carry out mathematical deduction (logical reasoning), select typical experiments, and finally draw a conclusion.
The success of observation-hypothesis-logical reasoning-experimental test is the result of ingenious combination of experimental physical thinking and mathematical deduction.
Newton's road to success
The founder of classical mechanics, calculus and optics.
Newton's main contributions in science are as follows: in mechanics, he put forward the three laws of motion and the law of universal gravitation; in optics, he made a judgment experiment that white light consists of seven colors of light, discovered and explained the interference phenomenon of Newton's rings, created reflecting telescope and put forward the theory of light particles; In mathematics, calculus operation method and infinite series theory have been discovered, and so on.
In Newton's time, Copernicus put forward Heliocentrism, Kepler studied and summarized the three laws of planetary motion from Tycho's observation data, Galileo gave the concepts of force and acceleration, and discovered the laws of inertia and free fall. However, these physical concepts and laws are still isolated and logically independent things. It was at this time that Newton made a comprehensive survey of the movements of planets and objects on the ground. He used mathematical methods to make physics a complete system, which can express causality. This is what we call the classical mechanical system (Newtonian mechanics) today.
Mathematics: Euclid → Descartes → Leibniz → Newton (calculus).
Mechanics: Da? 6? 1 finch → Galileo → huygens → Newton (three laws of motion)+
Astronomy: Copernicus → Tycho → Kepler → Newton (law of gravity)
Limitations of Newtonian mechanics
Absolute view of time and space, Newton said: "Absolute mathematical time has nothing to do with the outside world ..." That time and space are nothing.
Guan, space-time has nothing to do with motion, and it is an absolute physical quantity.
Newtonian mechanics is only applicable to low-speed macroscopic objects.
Particle theory of light
1704, Newton (representative); "Light is a kind of tiny particle with different sizes and fast movement."
Theory can explain linear propagation, reflection and photoelectric effect. Theory: Photon theory.
Wave theory of light
Representative: Huygens-Hook: "Light must be a vibration." The wave theory of light can explain the wave phenomena such as refraction, interference and diffraction of light, the principle of independent propagation of light, theory: electromagnetism, light is electromagnetic wave.
/kloc-two heroes of the wave theory of light in the 0/9th century
(1) Thomas? 6? 1 Yang (1773— 1829): Young's double-slit experiment was designed, and the interference phenomenon of light was proved. .
(2) Fresnel (1788— 1827): French engineer. Huygens theory is perfected and the concept of wavelet coherence is put forward. Famous Poisson Highlights: Fresnel Theory —— Poisson Calculation —— Poisson Highlights in favor of wave theory found in arago experiment.
Light has wave-particle duality;
The behavior of a single photon shows particle, while the behavior of a large number of photons shows fluctuation. The greater the photon wavelength, the more obvious the fluctuation, and the greater the photon frequency, the more obvious the particle nature. Light should have wave-particle duality.