tailieunhanh - English for students of Physics_Unit 2

21 Unit Two PHYSICS Physics is the major science dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces. Sometimes in modern physics a more sophisticated approach is taken that incorporates elements of the three areas listed above; it relates to the laws of symmetry and conservation, such as those pertaining to energy, momentum, charge, and parity. Physics is closely related to the other natural sciences and, in a sense, encompasses them. . | 21 Unit Two PHYSICS READING PASSAGE Physics and scopes of Physics Physics is the major science dealing with the fundamental constituents of the universe the forces they exert on one another and the results produced by these forces. Sometimes in modern physics a more sophisticated approach is taken that incorporates elements of the three areas listed above it relates to the laws of symmetry and conservation such as those pertaining to energy momentum charge and parity. Physics is closely related to the other natural sciences and in a sense encompasses them. Chemistry for example deals with the interaction of atoms to form molecules much of 22 modern geology is largely a study of the physics of the earth and is known as geophysics and astronomy deals with the physics of the stars and outer space. Even living systems are made up of fundamental particles and as studied in biophysics and biochemistry they follow the same types of laws as the simpler particles traditionally studied by a physicist. The emphasis on the interaction between particles in modern physics known as the microscopic approach must often be supplemented by a macroscopic approach that deals with larger elements or systems of particles. This macroscopic approach is indispensable to the application of physics to much of modern technology. Thermodynamics for example a branch of physics developed during the 19th century deals with the elucidation and measurement of properties of a system as a whole and remains useful in other fields of physics it also forms the basis of much of chemical and mechanical engineering. Such properties as the temperature pressure and volume of a gas have no meaning for an individual atom or molecule these thermodynamic concepts can only be applied directly to a very large system of such particles. A bridge exists however between the microscopic and macroscopic approach another branch of physics known as statistical mechanics indicates how pressure and temperature can be related