Atom Interferometer Measurement of the Newtonian Constant of Gravity
J. B. Fixler,1
G. T. Foster,2
J. M. McGuirk,3
M. A. Kasevich1*
We measured the Newtonian constant of gravity,
G, using a gravity
gradiometer based on atom interferometry. The gradiometer measures
the differential acceleration of two samples of laser-cooled
Cs atoms. The change in gravitational field along one dimension
is measured when a well-characterized Pb mass is displaced.
Here, we report a value of
G = 6.693
x 10
–11 cubic meters
per kilogram second squared, with a standard error of the mean
of ±0.027
x 10
–11 and a systematic error of ±0.021
x 10
–11 cubic meters per kilogram second squared. The
possibility that unknown systematic errors still exist in traditional
measurements makes it important to measure
G with independent
methods.
2 Department of Physics and Astronomy, City University of New York, Hunter College, New York, NY 10021, USA.
3 Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
* To whom correspondence should be addressed. E-mail: kasevich{at}stanford.edu
