Tests of Gravity Below Fifty Microns
Tests of Gravity Below Fifty Microns
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五十微米以下的重力测试
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
H. Leopardi
中科院分区：
文献类型：
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作者：
H. Leopardi
引力是第一个被数学描述的力，但它是唯一一个没有被很好理解的基本力。量子力学的标准模型描述了基本的强、弱和电磁力之间的相互作用，而爱因斯坦的广义相对论（GR）描述了引力的基本力。目前还没有一种理论能够统一广义相对论和量子力学之间的矛盾。弦理论的场景预测超过三个空间维度也预测了亚毫米级引力的物理效应，这将改变引力平方反比定律。弱等效原理（Weak Equivalence Principle，WEP）是广义相对论的一个核心特征，它指出所有物体在引力场中都以相同的速率加速，而与它们的组成无关。任何违反WEP的行为都将证明当前的重力模型是不正确的。在洪堡州立大学引力研究实验室，正在开发一项实验，以观察50微米距离尺度以下的引力相互作用。实验测量了平行板扭摆的扭曲，因为吸引子质量在摆的50微米内振荡，在摆上提供随时间变化的重力扭矩。扭矩幅度的大小和距离依赖性提供了确定在未经测试的距离尺度上与公认的重力模型的偏差的手段。为了观察真空室内平行板摆的扭曲，需要一个具有纳弧度精度的光学系统。
Gravity was the first force to be described mathematically, yet it is the only fundamental force not well understood. The Standard Model of quantum mechanics describes interactions between the fundamental strong, weak and electromagnetic forces while Einstein’s theory of General Relativity (GR) describes the fundamental force of gravity. There is yet to be a theory that unifies inconsistencies between GR and quantum mechanics. Scenarios of String Theory predicting more than three spatial dimensions also predict physical effects of gravity at sub-millimeter levels that would alter the gravitational inverse-square law. The Weak Equivalence Principle (WEP), a central feature of GR, states that all objects are accelerated at the same rate in a gravitational field independent of their composition. A violation of the WEP at any length would be evidence that current models of gravity are incorrect. At the Humboldt State University Gravitational Research Laboratory, an experiment is being developed to observe gravitational interactions below the 50-micron distance scale. The experiment measures the twist of a parallel-plate torsion pendulum as an attractor mass is oscillated within 50 microns of the pendulum, providing time varying gravitational torque on the pendulum. The size and distance dependence of the torque amplitude provide means to determine deviations from accepted models of gravity on untested distance scales. To observe the twist of the parallel-plate pendulum inside the vacuum chamber, an optical system with nanoradian precision is required.