Prove that heavy objects will not fall faster than light objects;
2. British scientist Newton
1683 put forward three laws of motion.
1687, publishing the law of universal gravitation;
3,17th century, Galileo's ideal experimental method pointed out that:
If there is no friction, an object moving on a horizontal plane will always move at this speed.
Einstein's Special Theory of Relativity
Classical mechanics is not suitable for microscopic particles and high-speed moving objects.
5,17th century German astronomer Kepler
Put forward Kepler's three laws;
6, 1798 British physicist cavendish.
The gravity constant was accurately measured with a torsion balance device.
7. Austrian physicist Doppler (1803- 1853)
It is found that due to the relative motion between the wave source and the observer, the observer feels the phenomenon of frequency change-Doppler effect.
8, 1827 British botanist Brown
Brownian motion is the phenomenon that pollen particles suspended in water keep irregular motion.
9, 1785 French physicist Coulomb
Coulomb's law of interaction between charges was discovered by torsion balance experiment.
Franklin 10, 1752
The kite experiment proved that lightning is a form of electricity, which unified the sky electricity and the earth electricity and invented the lightning rod.
German physicist Ohm (1787- 1854)
Ohm's law is obtained through experiments.
12, 19 1 1 year Dutch scientist anis.
When the temperature of most metals drops to a certain value, the resistance will suddenly drop to zero-superconductivity.
13, 184 1 ~ 1842 joules and cooling times.
They independently discovered the law of thermal effect when current passes through a conductor, which is called Joule-Lenz law.
14, 1820, Danish physicist Oster
The effect that current can deflect the surrounding magnetic needles is called current magnetic effect.
15 Dutch physicist Lorenz
It is pointed out that the moving charge produces a magnetic field, and the magnetic field has a force (Lorentz force) on the moving charge.
16, 183 1 year British physicist Faraday.
The conditions and laws of current generated by magnetic field-electromagnetic induction phenomenon are found.
17, 1834, cold time
The law of determining the direction of induced current.
Henry, 18, 1832
Discover the phenomenon of self-induction.
British physicist Maxwell
The existence of electromagnetic wave is predicted, and it is pointed out that light is electromagnetic wave, which lays the foundation for the electromagnetic theory of light.
20, 1887 German physicist Hertz
The existence of electromagnetic waves is confirmed by experiments, and the propagation speed of electromagnetic waves is determined to be equal to the speed of light.
2 1 BC, 468- 376 BC, Mo Zhai, China.
The Mohist Scripture records the phenomena of straight-line propagation of light, shadow formation, light reflection, imaging of plane mirror and spherical mirror, and is the earliest optical work in the world.
22, 162 1 year Dutch mathematician sneered.
The law between incident angle and refraction angle-refraction law.
23. There are two theories about the nature of light:
One is Newton's particle theory.
It is considered that light is a material particle emitted by a light source;
One is the wave theory put forward by the Dutch physicist Huygens.
People think that light is a wave that propagates in space.
24, 180 1 year, British physicist Thomas? white poplar
The interference of light was observed.
25, 18 18, French scientist Poisson.
The circular plate diffraction of light-Poisson bright spot was observed.
26, 1887 by Hertz
Confirmed the existence of electromagnetic theory.
27, 1895, German physicist Roentgen.
X-rays (roentgen rays) were discovered.
28, 1900, German physicist Planck.
Explain the law of thermal radiation of objects, and put forward that the emission and absorption of electromagnetic waves are not continuous, but one after another, bringing physics into the quantum world.
29, 1905 Einstein
The photon theory is put forward and the law of photoelectric effect is successfully explained.
30, 19 13, Danish physicist Bohr.
The hypothesis of atomic structure is put forward, and the radiation electromagnetic spectrum of hydrogen atom is successfully explained and predicted.
3 1, 1924, French physicist de Broglie.
Predicted the fluctuation of physical particles;
32, 1897, Thomson
The discovery of electrons by cathode ray tube shows that atoms can be separated and have complex internal structure, and a jujube cake model of atoms is proposed.
1909-1911year, British physicist Rutherford.
The scattering experiment of α particles is carried out, and the nuclear structure model of atoms is put forward. According to the experimental results, the nuclear diameter is estimated to be10-15 m.
34, 1896, French physicist becquerel.
The discovery of natural radiation shows that the nucleus also has a complex internal structure.
Rutherford, 35, 19 19
The nitrogen nucleus was bombarded with alpha particles, and the artificial transformation of the nucleus was realized for the first time, and protons were found.
36, 1932 Chadewei
Neutrons were found when α particles bombarded beryllium nuclei, from which people realized the composition of the nuclei.
37. 1932 discovered positrons, and 1964 proposed quark model;
Particles are divided into three categories: mediators, photons and other interacting particles;
Leptons, particles that do not participate in strong interactions, such as electrons and neutrinos;
Hadron, particles that participate in strong interactions, such as protons and neutrons; Hadron is composed of more basic particle quarks, and the charge of quarks may be or yuan charge.
thermology
1. 1827, British botanist Brown found that pollen particles suspended in water kept making irregular movements-Brownian motion.
2/kloc-In the middle of the 9th century, the law of conservation of energy was finally determined by German doctor Meyer, British physicist Joel and German scholar Helmholtz.
3. 1850, Clausius put forward the qualitative expression of the second law of thermodynamics: heat cannot be transferred from a low-temperature object to a high-temperature object without other effects, which is the so-called Clausius expression. The following year, Kelvin put forward another expression: it is impossible to obtain heat from a single heat source and convert it into useful work without other effects. This expression is called Kelvin expression.
4. 1848 Kelvin put forward the thermodynamic temperature scale, pointing out that absolute zero (-273. 15℃) is the lower limit of temperature. T=t+273. 15K
The third law of thermodynamics: zero degree of thermodynamics is unattainable.
5. Watt successfully developed a bidirectional steam engine with connecting rod, flywheel and centrifugal governor in 1782.
1897, Thomson discovered electrons with a cathode ray tube, indicating that atoms can be split and have complex internal structures, and put forward a jujube cake model of atoms.
2.1909 ——191year, British physicist Rutherford and his assistant conducted the scattering experiment of α particles and put forward the nuclear structure model of atoms. According to the experimental results, the nuclear diameter is estimated to be10-15 m.
3. 1896, French physicist becquerel discovered the phenomenon of natural radiation, indicating that the nucleus also has a complex internal structure.
There are two kinds of natural radiation phenomena (α, β) and three kinds of rays (α, β, γ), among which γ ray is radiated when the new nucleus is in an excited state and then decays and jumps to a low energy level. The decay rate (half-life) has nothing to do with the physical and chemical state of atoms.
4. In1919, Rutherford bombarded the nitrogen nucleus with alpha particles, which realized the artificial disintegration of the nucleus for the first time and discovered protons.
It is predicted that there is another kind of particle in the nucleus, which was discovered by chadwick, a student, when the α particle bombarded the beryllium nucleus in 1932, from which people realized that the nucleus is composed of protons and neutrons.
5. 1939 12 When German physicist Hahn and his assistant Strassman bombarded the uranium nucleus with neutrons, the uranium nucleus split. 1942, under the leadership of Fermi, szilard and others, the United States built the first fission reactor (consisting of enriched uranium rods, control rods, moderator, cement protective layer, etc.).
6. 1952 The United States exploded the world's first hydrogen bomb (fusion reaction, thermonuclear reaction). One possible way to artificially control nuclear fusion is to irradiate small nuclear fuel with high voltage generated by intense laser.
7. Modern particle physics;
1932 discovered positrons, and 1964 proposed quark model.
Particles are divided into three categories:
Mediator, particles that transmit photons and other interactions;
Leptons, particles that do not participate in strong interactions, such as electrons and neutrinos;
Hadron, particles that participate in strong interactions, such as protons and neutrons; Hadron is composed of more elementary quarks, and the charge of quarks may be 1/3 or 2/3 of that of elementary charge.
1. From 468 BC to 376 BC, Mo Zhai and his disciples recorded the linear propagation of light, the formation of shadows, the reflection of light, the imaging of plane mirrors and spherical mirrors in China, which is the earliest optical work in the world.
2. 1849 French physicist Fizeau first measured the speed of light on the ground, and later many scientists adopted more sophisticated methods to measure the speed of light, such as Michelson's rotating prism method. (Pay attention to its measurement method)
3. 162 1 year, the Dutch mathematician Snell discovered the law between incident angle and refraction angle-the law of refraction.
4. About the essence of light:17th century, two theories were clearly formed: one was the particle theory advocated by Newton, which believed that light was a kind of material particle emitted by a light source; The other is the wave theory put forward by Huygens, a Dutch physicist. He thinks that light is a wave propagating in space. Neither theory can explain all the light phenomena observed at that time.
180 1 year, British physicist Thomas? Yang successfully observed the interference of light.
18 18, French scientists Fresnel and Poisson calculated and experimentally observed the circular plate diffraction of light-Poisson bright spot.
Maxwell, a British physicist, predicted the existence of electromagnetic waves in 1864, pointing out that light is electromagnetic waves, which was confirmed by Hertz in 1887.
1895, the German physicist Roentgen discovered X-rays (Roentgen rays) and took the world's first X-ray human body photo for his wife's hand.
1900, the German physicist Planck proposed that the emission and absorption of electromagnetic waves were not continuous, but one after another, which brought physics into the quantum world. Inspired by it, Einstein put forward the photon theory in 1905, which successfully explained the law of photoelectric effect. (The explanation of quantum mechanics is in the third volume P56)
1922, American physicist Compton confirmed the particle nature of light when he studied the scattering of X-rays by electrons in graphite. (Explain that the law of conservation of momentum and the law of conservation of energy are applicable to microscopic particles at the same time)
Light has wave-particle duality, and light is electromagnetic wave, probability wave and shear wave (polarization of light means that light is shear wave).
In the electromagnetic theory of light, attention should be paid to the electromagnetic spectrum (Volume III P3 1) and the atomic spectrum (involving spectral analysis Volume III P50).
5. 19 13, Danish physicist Bohr put forward his own atomic structure hypothesis, which successfully explained and predicted the electromagnetic radiation spectrum of hydrogen atoms, laying the foundation for the development of quantum mechanics. (clarify its limitations)
6. 1924, French physicist de Broglie boldly predicted that physical particles would fluctuate under certain conditions; 1927, American and British physicists obtained the diffraction patterns of electron beams on metal crystals. Compared with optical microscope, electron microscope is much less affected by diffraction phenomenon, which greatly improves the resolution, and proton microscope has higher resolution instinct.
1. 1785, the French physicist Coulomb discovered the law of interaction between charges-Coulomb's law by using the torsion balance experiment. (transformation)
2. 1752, Franklin verified that lightning is a form of electricity through kite experiments in Philadelphia, unified the sky electricity with the earth electricity, and invented the lightning rod.
3. 1826 German physicist Ohm (1787- 1854) got Ohm's law through experiments.
4. 19 1 1 Dutch scientist anis found that when the temperature of most metals drops to a certain value, the resistance suddenly drops to zero-superconductivity.
5.1841~1842 Joule and Lengci have independently discovered the law of thermal effect when current passes through a conductor, which is called Joule-Lenz law.
6. 1820, Danish physicist Oster discovered the effect that current can deflect the surrounding magnetic needles, which is called the magnetic effect of current.
Ampere found that two parallel lines with the same current attract each other, while those with opposite currents repel each other. At the same time, the hypothesis of ampere molecular current is put forward.
Lorentz, a Dutch physicist, put forward the view that moving charge produces magnetic field, and the magnetic field has a force (Lorentz force) on moving charge.
7. The mass spectrometer designed by Thomson's student Aston can be used to measure the mass of charged particles and analyze isotopes.
1932, American physicist Lorenz invented the cyclotron, which can produce a large number of high-energy particles in the laboratory. (The maximum kinetic energy depends only on the magnetic field and the diameter of the D-box. The cycle of that circular motion of char particles is the same as that of the high-frequency pow supply; However, when the kinetic energy of particles is large and the speed is close to the speed of light, according to the special theory of relativity, the mass of particles increases significantly with the speed, and the cyclotron period of particles in the magnetic field changes, so it is difficult to further increase the speed of particles.
8. 183 1 year, the British physicist Faraday discovered the condition and law of magnetic field generating current-electromagnetic induction phenomenon;
1834 Lengci published the law of determining the direction of induced current.
9. 1832 Henry discovered the phenomenon of self-inductance, that is, while studying the induced current, he found that the induced electromotive force was caused by the current change of the circuit itself. The working principle of fluorescent lamp is one of its applications. Double winding precision resistance is one of the applications to eliminate its influence.
10. 1864, the British physicist Maxwell published the paper "Dynamic Theory of Electromagnetic Field", put forward the basic equations of electromagnetic field, later called Maxwell equations, predicted the existence of electromagnetic waves, pointed out that light is electromagnetic wave, and laid the foundation of electromagnetic theory of light. Electromagnetic wave is a kind of shear wave (note the diagram of P243 in Volume II).
1887 german physicist hertz confirmed the existence of electromagnetic waves through experiments and determined that the propagation speed of electromagnetic waves is equal to the speed of light.
mechanics
wind direction
Release date: April 23, 2009 at 22: 57: 14
1. 1638, in the dialogue between two new sciences, Italian physicist Galileo used scientific reasoning to prove that heavy objects would not fall faster than light objects.
Note: Galileo's study of free fall initiated a scientific method to study the laws of nature. (recalling the ideal inclined plane experiment)
2. 1683, British scientist Newton put forward three laws of motion in his book Mathematical Principles of Natural Philosophy.
3./kloc-in the 0/7th century, Galileo pointed out through ideal experimental methods: if there is no friction, an object moving on a horizontal plane will keep moving at this speed; Descartes, a contemporary French physicist, further pointed out that if there is no other reason, the moving object will continue to move in a straight line at the same speed, neither stopping nor deviating from the original direction.
4. Quantum mechanics and Einstein's special theory of relativity established at the beginning of 20th century show that classical mechanics is not suitable for microscopic particles and high-speed moving objects.
5./kloc-in the 0/7th century, the German astronomer Kepler put forward Kepler's three laws. Newton officially published the law of gravity in 1687; 1798, the British physicist Cavendish accurately measured the gravitational constant by using the torsion balance device (reflecting the idea of amplification and transformation); 1846, scientists calculated and observed Neptune by applying the law of universal gravitation.
6. The principle of the rocket invented in the Song Dynasty in China is the same as that of the modern rocket, but the structure of the modern rocket is complex, and the maximum speed that can be achieved mainly depends on the jet speed and the mass ratio (the mass ratio when the rocket starts flying and the fuel burns out); Multi-stage rockets are generally three-stage rockets, and China has become the third country to master manned space technology.
7./Kloc-In the 0/7th century, the Dutch physicist Huygens determined the periodic formula of a simple pendulum. A simple pendulum with a period of 2s is called a double pendulum.
8. Austrian physicist Doppler (1803- 1853) first discovered the phenomenon that the observer feels the frequency change due to the relative motion between the wave source and the observer-Doppler effect. (As we get closer to each other, F increases; Away from each other, f decreases)
1, Hooke: British physicist; Hooke's law (F-bomb =kx) was discovered.
2. Galileo: a famous Italian physicist; In Galileo's era, the instruments and equipment were very simple and the technology was relatively backward. However, Galileo skillfully used scientific reasoning to give the definition of uniform and variable speed motion, and deduced that S is proportional to t2, which was verified by experiments. Infer and test that no matter how heavy an object is, its free-falling speed is the same; Through the inclined plane experiment, it is concluded that the object will keep a uniform linear motion without external force. Newton later summed it up as the law of inertia. Galileo's scientific reasoning method is one of the greatest achievements in the history of human thought.
3. Newton: British physicist; The founder of dynamics, he summarized and developed the previous discoveries, and obtained Newton's law and the law of universal gravitation, which laid the foundation of classical mechanics based on Newton's law.
4. Kepler: Danish astronomer; Kepler's three laws of planetary motion were discovered, which laid the foundation for the law of universal gravitation.
5. cavendish: British physicist; Using torsion balance device skillfully to measure gravitational constant.
6. Brown: British botanist; Brownian motion was found when pollen suspended in water was observed by microscope.
7. Joule: British physicist; The mechanical equivalent of heat J=4.2 Joule/calorie is determined, which lays a solid foundation for the establishment of the law of conservation of energy transformation. Joule's law is obtained by studying the heat generated when current passes through a conductor.
8. Kelvin: British scientist; A thermodynamic temperature scale with -273℃ as zero degree was established.
9. Coulomb: French scientist; Clever use of "Coulomb torsion balance" to study the interaction between charges, and found "Coulomb's law".
10, Millikan: American scientist; Using the balance of charged oil droplets in vertical electric field, the elementary charge e is obtained.
1 1, ohm: German physicist; On the basis of experimental research, Ohm compared current with water flow, thus introducing the concepts of current intensity, electromotive force and resistance, and determining their relationship.
12, Oster: Danish scientist; It is found through experiments that current can produce magnetic field.
13, Ampere: French scientist; The famous molecular flow hypothesis was put forward.
14, Thomson: British scientist; Study cathode rays, find electrons, and measure the specific charge E/M of electrons. Thomson also put forward the "jujube cake model", which can explain some experimental phenomena at that time.
Lawrence: American scientist; The invention of "cyclotron" made mankind take a step forward in obtaining high-energy particles.
Faraday: British scientist; Discovered electromagnetic induction, personally made the world's first generator, and put forward the concepts of electromagnetic field, magnetic induction line and electric field line.
17 Lengci: German scientist; Summing up the test results, Lenz's law for determining the direction of induced current is published.
Maxwell: British scientist; Based on the previous research on electromagnetic induction, a complete electromagnetic field theory is established.
19, Hertz: German scientist; More than twenty years after Maxwell predicted the existence of electromagnetic waves, the existence of electromagnetic waves was first confirmed by experiments. The measured propagation speed of electromagnetic wave is equal to the speed of light, which proves that light is electromagnetic wave.
20. Huygens: Dutch scientist; In the study of light, the wave theory of light is put forward. Invented the pendulum clock.
2 1, Thomas? Yang: British physicist; Firstly, the problem of coherent light source is solved skillfully and simply, and the interference phenomenon of light is observed successfully. (Double-hole or Double-slit interference)
22. Roentgen: German physicist; After British physicist Herschel discovered infrared rays and German physicist Ritter discovered ultraviolet rays, it was found that when high-speed electrons hit the pipe wall, the pipe wall could emit X rays.
23. Planck: German physicist; A quantum concept-the energy of electromagnetic radiation (including optical radiation) is discontinuous, and E is proportional to the frequency υ. It also makes great contributions to thermodynamics.
Einstein, a German Jew who later joined the United States, was the greatest scientist in the 20th century. He put forward "photon" theory and photoelectric effect equation, and established special relativity and general relativity. The "mass-energy equation" is put forward.
25. De Broglie: French physicist; It is proposed that all microscopic particles have wave-particle duality; The concept of matter wave puts forward that any moving object has waves corresponding to it.
26. Rutherford: British physicist; Through the scattering phenomenon of α particles, the nuclear structure of atoms is proposed. Firstly, the artificial nuclear reaction was realized and protons were discovered.
27. Bohr: Danish physicist; Planck's quantum theory was applied to the atomic system, and Bohr put forward the atomic theory.
28. chadwick: British physicist; Neutrons were found in the experimental study of artificially transforming the nucleus.
29. Wilson: British physicist; Wilson Cloud Chamber was invented to observe the trajectories of α, β and γ rays.
30. becquerel: French physicist; The natural radiation of uranium was discovered for the first time, and it is complicated to begin to understand the nuclear structure.
3 1, Mary? Marie Curie: French (Polish) physicist, pioneer of atomic physics and discoverer of radium.
32. Iori Yagami? The Curies: French physicists; Daughter and son-in-law of the old Curie couple; First, it was found that radioisotopes were obtained by artificial nuclear transformation.