Why NIST Researchers Spent 10 Years Measuring Gravity

Executive Briefing & Key Highlights

Physicists have been trying to measure the fundamental gravitational constant for well over two centuries. The current accepted value of big G, as it’s known, is 6.67430 × 10-11 cubic meters per kilogram per square second. It also has an uncertainty of ±0.00015 × 10-11 m3/(kg s2). As far as constants of the universe go, that’s very uncertain. Stephan Schlamminger Schlamminger is a physicist at th