时间计量系统的演变

Evolution of time measurement systems

建立科学的时间计量系统是描述物质运动时间性的前提。古代人们在长期的生产和生活过程中，逐渐建立起了时间的概念，而后人们对时间计量系统的研究不断深入。时间计量系统的演变大致经历了如下几个阶段：古代的时间计量系统、世界时、历书时、原子时、协调世界时。现代科学研究一方面给时间计量的精度提出了更高的要求，另一方面也为提高时间计量精度创造了条件。目前，经过科学家们的不断努力，时间计量仍在朝着高精度方向不断发展。

The Scientific establishment of time measurement system is essntial to discribe the time feature of an object in movement. Ancient people gradually set up the concept of time in their productive activities of practice. Later on,the study on time became more and more profound. The evolution of time measurement system has experienced the following stages in general:the ancient time measurement systems, universal time, ephemeris time, atomic time and universal time coordinated. Modern Scientific research requires much higher accuracy of time measurement,and on the other hand,offers considerate possiblities to improve the accuracy of time measurement. Nowadays,owing to the ceaseless efforts of many scientists,time measurement is progressing towards high accuracy.