Renewal of “Understanding Gravity at the Smallest Scale”

更新“理解最小尺度的重力”

基本信息

批准号：
2108244
负责人：
Giorgio Gratta
金额：
$ 48万
依托单位：
Stanford University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-15 至 2024-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2108244&HistoricalAwards=false
关键词：
Renewal Understanding Gravity Smallest Scale

项目摘要

Understanding the nature of gravity at microscopic distances is one of the most important open problems in fundamental physics. Although General Relativity provides an extremely well-tested framework for describing gravitational effects at large distances, its connection with quantum mechanics and other fundamental interactions remains elusive. Indeed, the development of a quantum theory of gravity that can be incorporated into the Standard Model of fundamental interactions is a central goal of physics, with broad implications for our understanding of particle physics and the mysterious nature of the "dark energy" that appears to permeate the universe. Many theories attempting to provide a consistent microscopic framework for gravity (e.g., those involving extra dimensions) predict that gravity could deviate from the familiar inverse square law at sub-millimeter distances. Such deviations are extremely difficult to measure experimentally due to the small strength of gravitation and the presence of residual electromagnetic interactions. This grant funds the continuation of an experimental program in this area that has just started providing results.Previous measurements at these distance scales have employed techniques derived from human-size devices in which mechanical springs are used as part of force sensors. In the last few years, with the support of the NSF, the PI has developed a drastically new technique, using the light field of a laser to confine and measure the motion of micron-size quartz microspheres. In the last year the first full search for deviations from the inverse square law in the 10 micron range has been completed. While not yet competitive with the most sensitive measurements, this represents the first demonstration of the new technique that more directly measures forces at the range of interest, instead of extrapolating with objects that are larger than such range. In addition to this, the systematics are expected to be very different from those of other measurements and there are indications that background force models will soon be within reach. Additionally, the new technique used has been found to have many other applications in other areas of fundamental as well as applied physics. In the first category are searches for millicharged particles or tests of neutrality of matter, while inertial navigation and vacuum technology are examples of the second.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.

了解微观距离处的重力性质是基本物理学中最重要的开放问题之一。尽管一般相对论提供了一个经过良好测试的框架来描述大距离的重力效应，但它与量子力学和其他基本相互作用的联系仍然难以捉摸。确实，可以将重力理论的发展纳入基本相互作用的标准模型是物理学的核心目标，对我们对粒子物理的理解以及似乎渗透到宇宙的“暗能量”的神秘性质具有广泛的影响。许多试图为重力提供一致的显微镜框架（例如，涉及额外维度的理论）预测，重力可能会偏离亚毫米距离处熟悉的反平方法。由于重力的较小强度和残留电磁相互作用的存在，这种偏差极为难以实验测量。这项赠款资助了该领域的实验计划的延续，该计划刚刚开始提供结果。在这些距离尺度上进行的预防测量采用了从人类大小的设备中得出的技术，其中将机械弹簧用作力传感器的一部分。在过去的几年中，在NSF的支持下，PI使用激光的光场开发了一种急剧的新技术，以限制和测量微米大小的石英微球的运动。在去年，第一次完全搜索了10微米范围内的偏差法律偏差。尽管尚未与最敏感的测量值竞争，但这代表了新技术的首次演示，该技术更直接地测量了感兴趣范围的力，而不是用大于此类范围的对象进行外推。除此之外，预计系统学与其他测量值的系统有很大不同，并且有迹象表明背景力模型很快就可以触及。此外，已经发现所使用的新技术在其他基本和应用物理学领域具有许多其他应用。在第一类中是搜索物质中立性的粒子或中立性测试，而惯性导航和真空技术是第二个的例子。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛影响的审查标准通过评估来通过评估来支持的。