Published results of measurements of the gravitational constant, G, over the past 32 years. The solid circles denote measurements that employed torsion balances. The three lower solid squares show results that were obtained using a beam balance or two pendulums. The upper solid square is the result obtained by Rosi and colleagues1 using the technique of atom interferometry. The shaded area denotes the one-standard-deviation confidence interval of the value from the 2010 CODATA compilation of physical constants18.