New Frontiers in Experimental Gravitation

实验引力的新领域

• 批准号: 1305726
• 负责人: Eric Adelberger
• 金额: $ 135万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1305726&HistoricalAwards=false
• 关键词: New; Frontiers; Experimental; Gravitation

The University of Washington Eot-Wash Group will develop specialized instruments with unprecedented sensitivity for the ultra-weak forces suggested by some modern explanations for the apparent accelerated expansion of the Universe and by theoretical attempts to unify gravity with the other three fundamental forces. In particular, we will enhance the sensitivity to violations of the weak equivalence principle by a factor of about 10. This will test a key postulate of Einstein's laws of gravity, provide a laboratory test of the gravitational property of galactic dark matter, close a loophole in the ongoing Lunar-Laser-Ranging test of the strong equivalence principle, probe speculations about the source of the mysterious "dark energy" that apparently comprises two thirds of the total mass-energy of the Universe, set stringent constraints on Lorentz-symmetry-violation in gravity, and probe any idea that predicts ultra-feeble "fifth" forces. Additionally we will test Newton's inverse-square law down to length scales substantially smaller than the diameter of a human hair. This will probe for "large" extra dimensions, test a possible explanation for the observed smallness of the cosmological constant and rule out a large class of "chameleon" theories that were proposed to hide the many long-range interactions generated by string theories. These tests should be able to probe new gravitational-strength interactions with length scales down to 20 micrometers. We will search for new short-range spin-spin forces arising from exotic bosons using an electron-spin polarized pendulum/attractor instrument with 10-fold rotational symmetry.Because open questions about gravity are central to the gravitational, elementary-particle and cosmology communities and fascinate the scientifically literate community as well, (could anti-matter fall differently from matter? could the extra dimensions predicted by string theories have detectable effects? could dark matter have unusual long-range fields? is gravity truly the weakest force or could there be a whole regime of ultra-weak forces?) the Eot-Wash Group's work continues to have an unusually broad impact. Their results are widely disseminated through publications, invited talks and colloquia, invited review articles, lab tours, meetings with undergraduates at other universities and colleges, public lectures, and have been featured in magazine and newspaper articles in this country and in Europe. Group members have created a chapter on gravity and feature in a video documentary for the Annenberg Course "Physics for the 21st Century". The group's work has been featured in articles in Nature and The Economist and in an episode of "Through the Wormhole with Morgan Freeman". The broad range of scientific issues addressed by the Eot-Wash Group and the many technical challenges involved provide an excellent education in experimental physics and in high-tech instrumentation for graduate students and postdoctoral fellows, as well as unusually attractive opportunities for undergraduate research projects.

华盛顿大学厄特-沃什小组将研制出对超弱力具有空前灵敏度的专门仪器，这些超弱力是对宇宙明显加速膨胀的一些现代解释以及将引力与其他三种基本力统一起来的理论尝试所提出的。 特别是，我们将提高敏感性的弱等效原理的违反了约10倍。这将检验爱因斯坦引力定律的一个关键假设，为银河系暗物质的引力特性提供一个实验室测试，填补正在进行的强等效原理月球激光测距测试中的一个漏洞，探索关于神秘的“暗能量”来源的猜测，暗能量显然占宇宙总质能的三分之二，对引力中的洛伦兹对称性破坏设置严格的限制，并探索任何预测超微弱“第五”力的想法。此外，我们将测试牛顿平方反比定律的长度尺度远小于人类头发的直径。这将探测“大的”额外维度，测试对观测到的宇宙常数之小的可能解释，并排除一大类“变色龙”理论，这些理论被提出来掩盖弦理论产生的许多长程相互作用。这些测试应该能够探测新的引力-强度相互作用，其长度尺度可低至20微米。我们将使用具有10重旋转对称性的电子自旋极化摆/吸引器仪器来寻找由奇异玻色子产生的新的短程自旋-自旋力。因为关于引力的开放性问题是引力、基本粒子和宇宙学社区的核心，也吸引了科学素养社区，（反物质会与物质不同吗？弦论所预言的额外维度会有可探测的效应吗？暗物质会有不寻常的长程场吗引力真的是最弱的力吗？或者说，是否存在一整套超弱力？Eot-Wash小组的工作继续产生着不同寻常的广泛影响。他们的成果通过出版物、特邀演讲和座谈会、特邀评论文章、实验室图尔斯参观、与其他大学和学院的本科生会面、公开讲座等方式广泛传播，并在本国和欧洲的杂志和报纸文章中作了专题介绍。小组成员为安嫩伯格课程“21世纪世纪物理学”制作了一个关于重力的章节和一个视频纪录片。该小组的工作已在《自然》和《经济学人》的文章中以及《与摩根·弗里曼一起穿越虫洞》的一集中得到介绍。Eot-Wash Group解决的广泛的科学问题和所涉及的许多技术挑战为研究生和博士后研究员提供了实验物理学和高科技仪器方面的优秀教育，以及对本科研究项目的异常有吸引力的机会。