Probing Fundamental Physics with Gravitational Experiments

在现代物理学中，自然由两种理论描述。一种是“标准模型”，它用量子粒子描述了所有材料的特性；另一个是爱因斯坦描述万有引力的“广义相对论”。大多数物理学家认为这两种理论之间一定存在某种联系，但到目前为止，还没有实验证明这种联系。此外，暗物质和暗能量的发现表明，引力现象存在于广义相对论之外。华盛顿大学的研究小组专门测量超微弱的力，以寻找与广义相对论所描述的引力之间前所未有的微小偏差。虽然观测到任何与广义相对论的偏差都将是一项革命性的科学发现，但它也可能对GPS或下一代精密时钟的未来技术应用产生影响。该小组开发的技术和专业知识的应用范围从工业计量到地震预测。统一引力和粒子物理学的现代思想，以及对暗能量和暗物质的观察，表明引力的某些方面仍未被发现。华盛顿大学重力实验室（Eöt-Wash组）的桌面实验提供了一个独特的机会，可以在广义相对论，宇宙学和粒子物理学的交叉点上寻找新的物理学。该小组通过技术专长，创新以及对最相关的及时和永恒的物理问题的回应，在超弱力探测领域处于领先地位。具体来说，该小组将：1)测试等效原理（EP）：几乎可以肯定，广义相对论和标准模型之间的任何联系都违反了等效原理。该团队的扭力天平可以在100公里以下的距离进行最精确的ep测试。通过熔融硅扭转纤维的高灵敏度，将进行一种新的EP测量。该实验的普遍性和与宇宙学的相关性将通过用氢测试质量探测EP而得到增强。2)在短距离上测试牛顿平方反比定律：Eöt-Wash小组在41 μm的距离上测量和测试了重力。该小组将利用其专业知识设计并制造新的仪器，旨在测量和测试距离为25 μm的重力。3)推进低频超小力技术前沿：创新和具有挑战性的技术开发使集团取得了成功。展望未来的引力研究（包括LIGO），该小组将继续致力于低温仪器和干涉扭天平读数的开发。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In modern physics Nature is described by two theories. One is the “Standard Model,” which describes all material properties with quantum particles; the other is “General Relativity”, Einstein’s theory that describes gravitation. Most physicists think that there must be a connection between these two theories, but to date there is no experimental signature for such a connection. Furthermore, the discoveries of dark matter and dark energy suggest that gravitational phenomena exist that lie outside of General Relativity. The group at the University of Washington specializes in measuring ultra-feeble forces to search for unprecedentedly small deviations from gravity as described by General Relativity. While observing any deviations from General Relativity would be a revolutionary scientific discovery, it may also have consequences for future technical applications of GPS or next-generation precision clocks. Technology and technical expertise developed by this group has applications ranging from industrial metrology to earthquake prediction. Modern ideas for unifying gravity and particle physics, as well as the observation of dark energy and dark matter, suggest that some aspects of gravity remain undiscovered. The table-top experiments of the University of Washington gravity laboratory (Eöt-Wash Group) provide a unique opportunity to search for new physics at the intersection of General Relativity, cosmology, and particle physics. The group is a leader in the field of ultra-weak force detection through technical expertise, innovation, and by responding to the most relevant timely and timeless physics questions. Specifically, the group will:1) Test the equivalence principle (EP): It is almost certain that any connection between General Relativity and the Standard Model violates the EP. The group’s torsion balances provide the most precise EP-tests at distances below 100 km. With highly-increased sensitivity through fused silica torsion fibers, a new EP measurement will be carried out. The experiment’s generality and relevance to cosmology will be enhanced by probing the EP with hydrogen test masses. 2) Test Newton’s Inverse-Square Law at short distances: The Eöt-Wash group has measured and tested gravity at distances of 41 μm. The group will use its expertise to design and build a new instrument aimed at measuring and testing gravity down to distances of 25 μm. 3) Advance the frontier of low-frequency ultra-small-force technology: Innovative and challenging technology development has enabled the group’s success. With a vision towards the future of gravitational research (including LIGO), the group will continue pursuing development of cryogenic instruments and interferometric torsion balance readout.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.