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Gravitational Constant

All articles tagged with #gravitational constant

NIST's decade-long hunt keeps Big G from settling on a single precise value
science1 month ago

NIST's decade-long hunt keeps Big G from settling on a single precise value

NIST researchers spent a decade replicating a Cavendish-style experiment to measure Big G, testing copper and sapphire masses with an electrostatic twist, and report G = 6.67387×10^-11 m^3/kg/s^2—about 0.0235% lower than the BIPM value. The result adds another data point but does not resolve the long-standing discrepancy, highlighting gravity’s weakness and Earth’s background noise as ongoing challenges — while advancing precision instrumentation and metrology.

A Decade-Long Hunt Keeps Gravity’s Constant Unsettled
science1 month ago

A Decade-Long Hunt Keeps Gravity’s Constant Unsettled

A decade-long effort by NIST to measure the universal gravitational constant G, using a torsion-balance setup and multiple test masses, produced a value of 6.67387×10^-11 m^3/(kg·s^2) that is 0.0235% lower than the BIPM's result, sustaining a small but persistent discrepancy among precision measurements. An unusual blinding step— a colleague secretly altered some data to hide the true result until the envelope reveal—meant Schlamminger only learned the outcome at the end. Although the difference is too small to affect everyday life, it keeps G as an open question and underscores the need for further, careful measurements.