Collaborative Research: Testing the gravitational inverse square law and weak equivalence principle

现代物理学的一个主要目标是尽可能在最基本的水平上理解物质和能量的性质和行为。对爱因斯坦弱场（牛顿）引力的实证检验在判断这种理解的可能延伸方面起着重要作用。即使是牛顿行为的微小偏差，也可以为所谓的基本相互作用标准模型的更一般的表述提供新的线索，这是现代物理学的“圣杯”。这种偏差尚未被发现，但在过去十年的理论文献中，在低水平上预测这种异常的可能性比比皆是。该项目的目标是进行两个实验，通过对假定的非牛顿行为的强度设定至少一个数量级的更严格的经验上限，从而大大限制这些理论推测的可行性。或者，这些更精确的测量可以发现以前未被发现的偏差。这两种结果都将推进我们对宇宙物理结构的基本理解。华盛顿大学和加州大学欧文分校的研究小组之间的合作利用低温技术在测量精度方面取得了新的进展，新方法大大减少了系统影响，并提供了一个独特的实验室设施，提供超低振动环境。此外，这些活动还涉及年轻的科学家（博士后、研究生和本科生），以及合作伙伴波音飞机公司和机构赞助商太平洋西北国家实验室。

A primary goal of modern physics is to understand at the most fundamental level possible the nature and behavior of matter and energy. Empirical tests of Einstein's weak-field (Newtonian) gravity play an important role in judging possible extensions of this understanding. Even small deviations from Newtonian behavior could provide new clues to a more general formulation of the so-called Standard Model of fundamental interactions a "holy grail" of modern physics. Such deviations have not yet been detected, but the possibilities for expecting such anomalies at a low level abound in the theoretical literature over the past decade. The goal of this project is to carry out two experiments that will substantially restrict the viability of these theoretical speculations by setting at least an order-of-magnitude more stringent empirical upper limit on the strength of putative non-Newtonian behavior than already established. Alternatively, these more-precise measurements could uncover previously undetected deviations. Either outcome would advance our fundamental understanding of the physical fabric of our universe.This collaboration between research groups at the University of Washington and the University of California Irvine exploits new advances in measurement precision using cryogenic techniques, new methods dramatically to reduce systematic effects, and a unique laboratory facility that provides an ultra-low vibration environment. Moreover, these activities involve young scientists (post-docs, graduate and undergraduate students) as well as corporate partner Boeing Airplane Company and institutional sponsor Pacific Northwest National Laboratory.