Many scientists consider physics as the prototype of a science, and indeed, physics exhibits a number of features which can be r

admin2016-10-15  45

问题     Many scientists consider physics as the prototype of a science, and indeed, physics exhibits a number of features which can be regarded as highly desirable. 【F1】For example, the phenomenon it deals with can be described in precise terms and the relevant variables quantitatively measured; an enormous variety of phenomena may be explained by means of a few fundamental laws, which are formulated in mathematical terms and allow physicists to make quantitative predictions. It is therefore of particular interest to discuss what kind of assessment is used within the physical sciences. At the same time, the historical development of physics has taught us to exercise caution with respect to the goals which we may achieve.【F2】Though we are inclined to believe that the laws of physics are fundamental, their development has shown that even such laws may be applicable only to certain classes of phenomena. When more refined measurements are made, phenomena may appear whose explanation requires still more basic laws. Examples are the laws of classical mechanics, which at the atomic level had to be replaced by the laws of quantum mechanics.【F3】Mechanics valid for particles at comparatively small speeds had to be replaced by the theory of relativity for particles at speeds coming close to that of light.
    The belief in complete predictability has been shaken twice. First, around 1925 with the advent of quantum mechanics, it became clear that at the microscopic, atomic level events cannot be predicted with absolute precision.【F4】However, at the macroscopic dimension of our daily life these "statistical" effects are wiped out, and we can safely predict the path of a rocket sent to the Moon or to Jupiter. But it has recently become clear that even in macroscopic physics some phenomena cannot be predicted with a certain precision—which sheds new light on the limits of weather forecasting. The corresponding phenomena are called "deterministic chaos" and are the subject of research of new branches of theoretical physics(and mathematics). Finally, we must not overlook that, as in any other science, there are certain trends or "fashions" which play a temporary role in the development of physics. Such fashions are typical of cooperative effects in the scientific community. For example, dispersion relations in high-energy physics were in vogue in this field for a while, but today few are concerned with the approach. In spite of these remarks, physics still possesses an enormous degree of precision. Even if a single event cannot be predicted with absolute precision, it is still possible to make statistical predictions which can be checked by repeating the corresponding experiment.【F5】This possibility distinguishes physics from the historical sciences, where the course of events can never be repeated. It might be worth mentioning that events in our brain can never be totally repeated, due to memory and to learning.
【F3】

选项

答案适用于以较低速度运动的粒子的力学,对于以接近光速运动的粒子,必须用相对论取代。

解析
转载请注明原文地址:https://kaotiyun.com/show/TUoZ777K
0

最新回复(0)