New Frontiers in Experimental Gravitation

华盛顿大学EOT-Wash小组将开发具有前所未有的灵敏度的专门仪器，以应对一些现代解释对宇宙明显加速膨胀的超弱力的建议，并从理论上尝试将重力与其他三种基本力量统一起来。特别是，我们将把对违反弱等价原理的敏感性提高约10倍。这将测试爱因斯坦引力定律的一个关键假设，提供银河系暗物质引力性质的实验室测试，填补正在进行的强等价原理月球激光测距测试中的漏洞，探索神秘的“暗能量”的来源猜测，显然，这种神秘的“暗能量”显然占宇宙总质量能量的三分之二，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的“第五”力的想法。此外，我们还将测试牛顿的平方反比定律，精确到远小于人类头发直径的长度尺度。这将探索“大”的额外维度，测试对观测到的宇宙学常数微小的可能解释，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远程相互作用。这些测试应该能够探测新的引力-强度相互作用，长度尺度可以达到20微米。我们将使用具有10倍旋转对称性的电子自旋极化摆/吸引器来寻找来自奇异玻色子的新的短程自旋-自旋力。因为关于引力的公开问题是引力、基本粒子和宇宙学的核心，也吸引了有科学素养的社区，(反物质是否会与物质不同？弦理论预测的额外维度会有可检测到的影响吗？暗物质会不会有不同寻常的远程场？引力真的是最弱的力吗？或者可能存在一个由超弱力组成的完整机制？)EOT-Wash小组的工作继续产生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、特邀评论文章、实验室参观、与其他大学和学院的本科生会议、公开讲座等方式广泛传播，并已在英国和欧洲的杂志和报纸文章中亮相。小组成员在Annenberg课程“21世纪的物理学”的视频纪录片中创建了一个关于引力和专题的章节。该团队的研究成果曾出现在《自然》和《经济学人》的文章中，并出现在《与摩根·弗里曼一起穿过虫洞》的一集中。EOT-Wash集团解决了广泛的科学问题和涉及的许多技术挑战，为研究生和博士后提供了极好的实验物理和高科技仪器教育，并为本科生研究项目提供了极具吸引力的机会。

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.