Tests of Newtonian Gravitation and the Weak Equivalence Principle

一项引力实验室实验计划将继续进行并扩大。 重点将放在测试爱因斯坦弱等效原理（EP）的仪器上，以及引力常数G的高精度测量。 最适合这项研究的仪器是经典的扭力天平。 在现代形式下，这种仪器在测量缓慢变化的极小力的能力方面是显着的，但在室温下操作时，它现在正在接近其能力的极限。 这项研究计划的一个重要推动力将是新一代扭转平衡仪器的开发和应用，该仪器在低温下工作，由于较低的热噪声和更大的机械稳定性，灵敏度大大提高。

A program of laboratory experiments in gravitation is to be continued and expanded. Emphasis will be on instrumentation for tests of Einstein's weak equivalence principle (EP), and a high accuracy measurement of the gravitational constant G. The instrument best suited for this research is the classic torsion balance. In modern form this instrument is remarkable in its capability to measure slowly varying extremely small forces, but it is now approaching the limits of its abilities when operated at room temperature. An important thrust of this research program will be the development and application of a new generation of torsion balance instruments which operate at cryogenic temperatures with greatly increased sensitivity due to lower thermal noise and greater mechanical stability.