NSF Ideas Laboratory at NIST: Measuring "Big G" Challenge

牛顿常数G是决定质量之间引力吸引力的基本常数。 它是迄今为止最不为人所知的自然界基本常数。 令人不安的是，近几十年来，世界各地的实验室对G的测量所得出的数值之间的差异远远超过了它们所指定的不确定度。 为了应对这种情况，NIST（国家科学技术研究所）将举办为期一周的“思想实验室”，汇集来自广泛科学学科的科学家，探索如何对这一基本常数进行新的明确和准确的测量。 最好的想法将被纳入预期的NSF资金的建议。 随着我们对理论物理学的理解的进步，很可能会有一天，G的精确已知值将检验试图将引力与量子理论统一起来的理论。与此同时，理解精确和绝对测量小力所涉及的微妙之处对物理学和计量学的许多领域都很重要。事实上，最近测量的G值的不一致性表明了用于测量它们的仪器的根本误解的可能性很小，其理解可能对物理理论产生重要影响。NSF“想法实验室”，测量“大G”挑战，将于2016年7月18日至22日在NIST的盖瑟斯堡设施举行。来自不同科学领域的参与者将共同努力，探索对牛顿基本常数G进行新的确定性测量的方法。最有前途的想法将导致合作的建议，以国家科学基金会的资金。 最初的NSF拨款将包括约20名实验室参与者（15名受邀参与者加上5名主任和导师）的注册，旅行和住宿以及注册。这些支出将由加州大学欧文分校管理。

Newton's constant, G, is the fundamental constant which determines the attractive gravitational force between masses. It is by far the least well known of the fundamental constants of nature. Disturbingly, measurements of G in recent decades by laboratories world-wide have yielded numerical values which differ among themselves by far more than their assigned uncertainties. In response to this situation a week-long "Ideas Lab" is to be conducted at NIST (National Institute of Science and Technology) to bring together scientists from a wide range of scientific disciplines to explore ways to make a new definitive and accurate measurement of this fundamental constant. The best ideas so developed will be incorporated in proposals for anticipated NSF funding. As our understanding of theoretical physics advances it is likely that there will come a time when an accurately known value of G will test theories that attempt to unify gravitation with quantum theory. In the meantime, understanding the subtleties involved in precisely and absolutely measuring a small force is important for many fields of physics and metrology. Indeed, the disagreement of recently measured G values suggests the remote possibility of fundamentally misunderstood properties of the instruments used to measure them, whose understanding could have important consequences for physical theories.An NSF "Ideas Lab", Measuring "Big G" Challenge, is to be held July 18-22, 2016 at NIST's Gaithersburg facility. Participants drawn from a wide range of scientific disciplines will work together to explore ways to make new definitive measurements of Newton's fundamental constant G. The most promising ideas will lead to collaborative proposals to NSF for funding. The initial NSF grant will cover registration, travel and lodging for about 20 Lab participants (15 invited participants plus 5 Director(s) and Mentors) and registration. These expenditures will be administered by the University of California, Irvine.