Gravity Probe A
重力探测器A
Launched in 1976 for a suborbital mission lasting 1 hr and 55 minutes, Gravity Probe A carried a precise clock to explore the structure of space and time. The experiment used the highly accurate atomic hydrogen MASER atomic clock, and recorded how it measured time as it rose to weaker levels of gravity, then fell back to the Earth. The purpose of the experiment was to determine whether time progressed at a different rate in conditions where gravity is weaker. This difference in the rate of passage of time, predicted by Einstein's Theory of Relativity, is called the "redshift." The primary objective of the mission was to test a portion of Einstein's gravitation and relativity theories called the "Principle of Equivalence," to an accuracy of 200 parts per million.
1976年发射的Gravity Probe A任务持续了1小时55分钟，是一项亚轨道任务，它携带了一块精确的钟表，以探索空间和时间的结构。该实验使用了高精度的原子氢MASER原子钟，记录了当它升到重力较弱的区域时，钟表如何测量时间，然后又回落到地球。该实验的目的是确定在重力较弱的条件下，时间是否以不同的速率流逝。这种时间流逝速率的差异，根据爱因斯坦的相对论预测，被称为“红移”。任务的主要目标是将爱因斯坦的引力和相对论理论中的“等效原理”测试到百万分之200的精度。 The Gravity Probe A payload was launched in 1976 from the NASA-Wallops Flight Center in Virginia. It followed an elliptical flight trajectory over the Atlantic, attaining an altitude of 10,000km (6,200 miles) above the Earth before crashing into the Atlantic Ocean.
During this short trip, GP-A transmitted accurate measurements of slight changes in the clock's rate in lower gravity, and provided the best test of this portion of Einstein's theories that has been performed to date.
At the peak height of 10,000 km the clock should run 4.5 parts in 1010 faster than on the Earth's surface according to general relativity. The MASER clock's accuracy was reported to be 1 part in 10-15. The observed effects matched the prediction to an accuracy of about 70 parts per million.
根据广义相对论，在10,000公里的高度上，钟应该比在地球表面快4.5个部分每10¹⁰。MASER钟的精度被报告为每10¹⁵部分1个。观测到的效果与预测的精度相符，约为70万分之一。
References:
重力探测器A的有效载荷于1976年从弗吉尼亚的NASA-沃洛普斯飞行中心发射。它沿着一条经过大西洋的椭圆飞行轨迹飞行，最高达到约10,000公里（6,200英里）的海拔，随后坠入大西洋。在这次短暂的飞行中，GP-A传回了关于在较低重力环境下钟速率微小变化的精确测量数据，并提供了到目前为止对爱因斯坦理论这一部分的最佳测试。参考文献： NASA Gravity Probe-A
NASA 重力探测器A Wiki Gravity Probe-A
Wiki Gravity Probe-A（专名或术语） |
