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.
