西南交通大学：《大学物理》课程教学资源（讲稿，双语）CHAPTER 1 PreIude

UNIVERSITY PHYSICS I CHAPTER 1 Prelude 81.1 Physics as Natural Philosophy Physics is one of the liberal arts combining elements of reason, philosophy, mathematics, language, and rhetoric. The term natural philosophy reflects the creative and dynamic interplay that exists in physics among experiment, theory, logic, insight, inspiration, symmetry, beauty, and language

1 §1.1 Physics as Natural Philosophy Physics is one of the liberal arts, combining elements of reason, philosophy, mathematics, language, and rhetoric. The term natural philosophy reflects the creative and dynamic interplay that exists in physics among experiment, theory, logic, insight, inspiration,symmetry, beauty, and language

81.1 Physics as Natural Philosophy 1. Developing Theories The goal of the theory is to integrate as many observations of nature as possible under one conceptual umbrella-to discover how little must be known to explain as much as possible. For instance: Newton’ s theory→ Einstein,s relativity (P2 colum 2 paragraph 2) KIS principle: Keep It simple 1.1 Physics as Natural Philosophy Characteristics of a good physical theory 1 Include all known relevant observations and measurements 2.A 3. Lead to new observations and and different measurements experiments with with minimal results that are complexity consistent with the predictions of the leery

2 §1.1 Physics as Natural Philosophy 1. Developing Theories The goal of the theory is to integrate as many observations of nature as possible under one conceptual umbrella—to discover how little must be known to explain as much as possible. (P2 colum 2 paragraph 2) KIS principle: Keep It Simple. For instance: Newton’s theory → Einstein’s relativity §1.1 Physics as Natural Philosophy Characteristics of a good physical theory 1. Include all known relevant observations and measurements 2.Account for observations and measurements with minimal complexity 3. Lead to new and different experiments with results that are consistent with the predictions of the theory

81.1 Physics as Natural Philosophy 2. Physics and equations If you feel that understanding physics amounts to memorizing myriad equations and formulas and then searching for a "magic bullet" among them, you have missed the forest for the trees “ Doing physics” is the reasoning that leads from observations and experiments to a mathematical model or explanation of them 81.1 Physics as Natural Philosophy 3. Language and physics When writing physics, one must be as precise as when crafting a legal document. When reading physics or the law, you likewise must be careful deliberate

3 §1.1 Physics as Natural Philosophy 2. Physics and equations If you feel that understanding physics amounts to memorizing myriad equations and formulas, and then searching for a “magic bullet” among them, you have missed the forest for the trees. “Doing physics” is the reasoning that leads from observations and experiments to a mathematical model or explanation of them. §1.1 Physics as Natural Philosophy 3. Language and Physics When writing physics, one must be as precise as when crafting a legal document. When reading physics or the law , you likewise must be careful, deliberate

81.2 Contemporary Physics: classical and modern $1.2 Contemporary Physics: classical and modern Observation of nature and experimental results typically precede the general theories that account for them 1. Kinematics and Dynamics Kinematics invented by Galileo Galilei is a theory that describes quantitatively motion Dynamics invented by Issac Newton is a theory that explained the causes of motion Principia is the first comprehensive physical theory 81.2 Contemporary Physics: classical and modern 2. Electricity and Magnetism The theory of electromagnetism integrated by James Clerk maxwell is the second great physical theory of natural Philosophy. Benjamin Franklin, Charles Coulomb, Christian Oersted, Michael Faraday. This theory predicted the existence of electromagnetic wave Light is electromagnetic wave

4 §1.2 Contemporary Physics: classical and modern Observation of nature and experimental results typically precede the general theories that account for them. 1. Kinematics and Dynamics Kinematics invented by Galileo Galilei is a theory that describes quantitatively motion. Dynamics invented by Issac Newton is a theory that explained the causes of motion. Principia is the first comprehensive physical theory. §1.2 Contemporary Physics: classical and modern §1.2 Contemporary Physics: classical and modern 2. Electricity and Magnetism The theory of electromagnetism integrated by James Clerk Maxwell is the second great physical theory of natural Philosophy. Benjamin Franklin, Charles Coulomb, Christian Oersted, Michael Faraday. This theory predicted : the existence of electromagnetic wave; Light is electromagnetic wave

31.2 Contemporary Physics: classical and modern 3. Thermodynamics Engine efficiency (Sadi Carnot)dissipation of mechanical energy and heat transfer (James Prescott Joule)entropy (rudolf Clausius)the statistical meanings of entropy ( ludwig Boltzmann) Willard Gibbs) The physical laws of thermodynamics 31.2 Contemporary Physics: classical and modern 4. Modern Physics relativity developed by albert einstein in 1905 is a more general theory of space, time, and motion Quantum mechanics is the theory developed during the1920s by such giants of 20th-centur hysics as Erwin Schrodinger, wolfgang Pauli, Werner Heisenberg, P.A. M.Dirac, Niels Bohr, and Enrico fermi, all of whom eventually became Nobel laureates in physics

5 §1.2 Contemporary Physics: classical and modern 3. Thermodynamics Engine efficiency(Sadi Carnot)—dissipation of mechanical energy and heat transfer(James Prescott Joule)—entropy(Rudolf Clausius)—the statistical meanings of entropy(Ludwig Boltzmann) The physical laws of thermodynamics (Willard Gibbs) §1.2 Contemporary Physics: classical and modern 4. Modern Physics relativity developed by Albert Einstein in 1905 is a more general theory of space, time, and motion. Quantum mechanics is the theory developed during the1920s by such giants of 20th-century physics as Erwin Schrodinger, Wolfgang Pauli, Werner Heisenberg, P.A.M.Dirac, Niels Bohr, and Enrico Fermi, all of whom eventually became Nobel laureates in physics

31.2 Contemporary Physics: classical and modern This theory integrated many phenomena such as: X-ray, radioactivity, electron, radiation of blackbody, photoelectric effect, quantization of angular momentum and energy. Kinematics and dynamics Classical physics Electromagnetism Thermodynamics Relativity (special and general) Modern physics Quantum mechanics 81.3 Why must we study physics I. What is physics? Physics studies fundamental structures fundamental interactions of substances and fundamental laws of motion of matter in various structure level Physics is foundation to all natural sciences technologies and engineerings Physics education should be the education of science diathesis 6

6 §1.2 Contemporary Physics: classical and modern This theory integrated many phenomena such as: X-ray, radioactivity, electron, radiation of blackbody, photoelectric effect, quantization of angular momentum and energy. Classical physics Modern physics Kinematics and dynamics Electromagnetism thermodynamics Relativity(special and general) Quantum mechanics §1.3 Why must we study physics 1. What is physics? Physics is foundation to all natural sciences, technologies and engineerings. Physics education should be the education of science diathesis. Physics studies fundamental structures , fundamental interactions of substances, and fundamental laws of motion of matter in various structure level

51.3 Why must we study physics 2. The relationships among the physics and other disciplines Ophysics and astronomy astronomical observation physics s1.3 Why must we study physics THE UNIVERSE HE UNIVERSE contains everything that exists-not only the Earth and everything on it, but also all the planets, stars, at them, The sun. at the center of th solar system, is just one of about Galaxies Way, Astronomers have estimate hat there are about 100 billion scientists think that the universe formed about 15 billion years THe Earth and the sola enormous explosion called also think that the universe galaxies in the universe

7 §1.3 Why must we study physics 2. The relationships among the physics and other disciplines 1physics and astronomy astronomical observation physics §1.3 Why must we study physics

51.3 Why must we study physics Einstein EINSTEINS THEORY OF GRAVITATION SU ggested E NSTE IN sugested that gravitation, or gravity, results Proving the theory that a bod the Earth, will make something I can be seen to bend like a dent in with a ght, will be drawn into the dent alongside it arge Small body mass will Einstein ' s theory bent space that a heauy ball will Large mass Line of orbit 8 1.3 Why must we study physics Einstein ring and gravitation lens 8

8 §1.3 Why must we study physics Einstein suggested that a body with a large mass will bent space. §1.3 Why must we study physics Einstein ring and gravitation lens

s1.3 Why must we study physics ② Physics and biology Organisms are made up of atoms and molecules, which obey physical laws. 81.3 Why must we study physics A magnetic resonance image of the head Physics provides the research methods for biology biological die

9 §1.3 Why must we study physics 2Physics and biology Organisms are made up of atoms and molecules, which obey physical laws. §1.3 Why must we study physics A magnetic resonance image of the head Physics provides the research methods for biology and biological medicine

s1.3 Why must we study physics X-ray photograph of a human 81.3 Why must we study physics The reattachment of detached retinas by means of lasers 10

10 §1.3 Why must we study physics §1.3 Why must we study physics The reattachment of detached retinas by means of lasers