利用布拉维摆测量地球自转的实验研究

Experimental research on measuring the earth's rotation with Bravais pendulum

地球自转会带来许多非惯性系效应,利用这些效应定量测量地球的自转角速度,是物理学实验研究的一个重要方面,其中,布拉维摆不仅可以定性地体现出地球自转的效应,更是一种精密测定其自转周期的一种方法.深入研究了利用圆锥摆顺时针和逆时针旋转的周期不同测量地球自转角速度的实验,分析了实验中影响测量精度的关键因素并探讨了控制实验误差的方法,最终得到了与标准值偏差2.3%的结果.由于地球自转所导致的顺逆周期的差十分微小,而影响周期测量的因素很多,如何控制其中关键因素的误差就成为实验成功的重要环节.介绍了如何控制实验条件,以及一些重要的误差来源的分析和控制,对于在普通物理实验条件下成功进行地球自转角速度的测量具有借鉴意义.

The earth s rotation brings a lot of non-inertial effects.It is a significant aspect of physics experimental research to measure rotational angular velocity of the earth quantitatively with these effects.Among them,Bravais pendulum can no longer present the effect of the earth qualitatively,but also provides a method to measure its rotation period precisely.We explore the experiment deeply which is conducted to measure the earth s angular velocity by the difference of periods clockwise and counterclockwise.We also analyze the key factors that influence the accuracy of measurement and discusses the ways to control the experimental errors.Finally,we get the result with 2.25% deviation compared to the standard value.Since the difference caused by the earth s rotation between periods clockwise and counterclockwise is quite tiny and there are abundant factors influencing the measurement of periods,to control the major errors becomes vital to the success of this experiment.We introduce the ways to control the condition and some analysis of some important deviation sources.It can ben taken as a reference for measuring rotational angular velocity of the earth under plain condition.