Null Test of Newton's Law of Gravitation on a 100-Micrometer Scale

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。这项研究的目的是在100微米的范围内将牛顿的平方反比引力定律测试到1%，并在几十微米的范围内寻找额外的维度或其他新物理。 实验将被冷却到液氦温度。 为了尽量减少牛顿误差，实验采用了近零源，一个大直径与厚度比的圆盘。 两个测试质量，也是圆盘形的，被定位在源质量的两侧，非常接近。 当源被驱动时，由于对称性，跨测试质量的差分加速度信号应该以驱动频率的两倍出现。 该信号由超导差分加速度计检测，这是一种高灵敏度的重力传感器。 这项研究将探索时空的本质，并测试广义相对论和粒子物理学标准模型以外的理论的基础。 在短距离内观察到牛顿定律的偏离将彻底改变我们对引力的理解，可能是一种对弦理论潜在实验证实的方法，并可能揭示神秘的宇宙学常数问题。 这类研究基本上是可以理解的，对公众来说是令人兴奋的，从而激发了他们对基础科学的兴趣。 本实验室为测量极弱的力而开发的低温技术的进一步改进在各种其他精密测量领域具有潜在价值。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The objective of this research is to test Newton's inverse-square law of gravitation to 1% at a 100-micrometer range and to search for extra dimensions or other new physics down to a few tens of micrometers. The experiment will be cooled to liquid helium temperatures. To minimize Newtonian errors, the experiment employs a near-null source, a circular disk of large diameter-to-thickness ratio. Two test masses, also disk-shaped, are positioned on the two sides of the source mass at close proximity. As the source is driven, the differential acceleration signal across the test masses should appear at twice the drive frequency due to symmetry. The signal is detected by a superconducting differential accelerometer, which is a highly sensitive gravity sensor. This research will explore the very nature of spacetime and test foundations of General Relativity and theories beyond the Standard Model of particle physics. The observation of a deviation from Newton's law at short distance would revolutionize our understanding of gravity, could be an approach the potential experimental confirmation of string theory, and could possibly shed light on the mystifying cosmological constant problem. This sort of research is basically understandable and exciting to the public, thus stimulating their interest in fundamental science. Further refinement of the cryogenic techniques that this laboratory has developed for measuring extremely weak forces is of potential value in a variety of other fields of precision measurement.