The gravitational constant, G, describes the strength of gravitation, the weakest of the four fundamental interactions in nature.
Although several hundred measurements of this constant have been performed over the last two and a quarter centuries, recent experiments differ by as much as 0. 05%,
about 40 times the uncertainty of the most precise experiment.
Motivations to resolve the current discrepancy with better measurements are two-fold.
First, the search for a theory that unifies gravitation with quantum electrodynamics is an active area of research.
Such a theory may be able to predict the value of G, and an experimental result may become important to test such theories.
Second, understanding the subtleties involved in precisely and absolutely measuring a small force is important for many fields of physics and metrology, including the Casimir effect, spring constants of atomic force microscopy (AFM) cantilever, intermolecular forces in DNA.
This solicitation describes an Ideas Lab on "Measuring Big G" Ideas Labs are intensive meetings focused on finding innovative solutions to grand challenge problems.
The ultimate aim of this Ideas Lab organized by the Physics Division of the Mathematical and Physical Sciences Directorate at the National Science Foundation (NSF), in collaboration with experts in the field, is to facilitate the development of new experiments designed to measure Newton’s gravitational constant G with relative uncertainties approaching or surpassing one part in 100,00 0. The aspiration is that mixing researchers from diverse scientific backgrounds will engender fresh thinking and innovative approaches that will provide a fertile ground for new ideas on how to measure G that can be used to validate and extend current calculations.
US researchers may submit preliminary proposals for participation in the Ideas Lab only via FastLane.
The goal is to develop multidisciplinary ideas that eventually will be submitted as full proposals.