# NIST gravity measurement deepens disagreement over fundamental constant

_Published Sunday, September 20, 2026 at 2:08 PM EDT · Science · Latest · Tier 2 — Notable_

![NIST gravity measurement deepens disagreement over fundamental constant — Primary](https://www.sciencedaily.com/images/1920/astrophysics-black-hole-rotating-light-gravity.webp)

A decade-long NIST experiment measured the universal gravitational constant at 6.67387 × 10-11 meters cubed per kilogram per second squared, 0.0235% below a leading 2007 French measurement using a similar approach. The team used blinded data analysis and tested copper and sapphire masses, which produced essentially the same result. Researchers say unrecognized experimental effects remain the likeliest explanation for the mismatch.

## Sources

- [All Top News -- ScienceDaily](https://www.sciencedaily.com/releases/2026/09/260920032049.htm)

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Canonical: https://techandbusiness.org/newswire/0vy0Kue0MnXhk80pclR8O_
Published: 2026-09-20T18:08:04.622Z
Story chronology: 2026-09-20T10:30:31.000Z
Retrieved: 2026-09-20T20:00:57.277Z
Publisher: Tech & Business (techandbusiness.org)