Weighing in on the mystery of the gravitational constant

Phys · Apr 16, 2026 · 1304 words · By National Institute; Technology

Physicist Stephan Schlamminger and his team at NIST conducted a decade-long effort to measure the universal gravitational constant (big G) using a torsion balance. Their results showed a slight discrepancy compared to a previous French experiment, contributing further data to the ongoing scientific effort to precisely determine the constant.

open_in_new Read the original article: https://phys.org/news/2026-04-mystery-gravitational-constant.html

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Low risk. This article shows minimal use of propaganda techniques.

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10 claims extracted and verified against multiple sources including cross-references, web search, and Wikipedia.

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verified Verified By Reference 2

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“Stephan Schlamminger, a physicist at the National Institute of Standards and Technology (NIST), spent most of his working hours for the past 10 years trying to measure the universal gravitational constant.”

CORROBORATED

Multiple independent sources (NIST, Scientific American, Big Think) confirm that Stephan Schlamminger's effort to measure the gravitational constant was a decade-long undertaking.

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wikipedia NEUTRAL — The kilogram (also spelled kilogramme) is the base unit of mass in the International System of Units (SI), equal to one thousand grams. It has the unit symbol kg. The word "kilogram" is formed from th…
https://en.wikipedia.org/wiki/Kilogram

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wikipedia NEUTRAL — The gravitational constant is an empirical physical constant that gives the strength of the gravitational field induced by a mass. It is involved in the calculation of gravitational effects in Isaac N…
https://en.wikipedia.org/wiki/Gravitational_constant

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wikipedia NEUTRAL — A Kibble balance (also formerly known as a watt balance) is an electromechanical measuring instrument that measures the weight of a test object very precisely by the electric current and voltage neede…
https://en.wikipedia.org/wiki/Kibble_balance

+ 3 more evidence sources

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“Scientists have been trying to measure the constant for over 225 years, a century after Isaac Newton published his famous law of gravitation.”

VERIFIED BY REFERENCE

The evidence explicitly states that Henry Cavendish made the first measurement of G in 1798, which was a century after Newton's discovery of the law of universal gravitation, and that attempts have continued for over two centuries.

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wikipedia NEUTRAL — Cameron Jerrell Newton (born May 11, 1989) is an American former professional football quarterback who played in the National Football League (NFL) for 11 seasons, primarily with the Carolina Panthe…
https://en.wikipedia.org/wiki/Cam_Newton

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wikipedia NEUTRAL — In physics, gravity (from Latin gravitas 'weight'), also known as gravitation or a gravitational interaction, is a fundamental interaction, which may be described as the force that draws material obj…
https://en.wikipedia.org/wiki/Gravity

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“its value remains the least well-known of the four fundamental forces in nature, which also include electromagnetism and the strong and weak nuclear forces.”

CORROBORATED

Multiple sources confirm that gravity is the weakest of the four fundamental forces and that the gravitational constant is the least precisely known of them.

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web search NEUTRAL — There are four fundamental interactions known to exist: gravity, electromagnetism, weak interaction, and strong interaction.[1] The gravitational and electromagnetic interactions produce long-range fo…
https://en.wikipedia.org/wiki/Fundamental_interaction

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web search NEUTRAL — That's in part because gravity is the weakest of the four forces. Even a magnet no bigger than the head of a pin can levitate a paper clip off the floor, exerting an electromagnetic force far greater …
https://phys.org/news/2026-04-mystery-gravitational-constant…

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web search NEUTRAL — Even today, it is the least precisely known of the four fundamental forces, which also include electromagnetism and the strong and weak nuclear forces. One challenge is that gravity is far weaker than…
https://scitechdaily.com/the-most-elusive-number-in-physics-…

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“Schlamminger and his colleagues sought to find out by painstakingly replicating a precision experiment conducted by the International Bureau of Weights and Measures (BIPM) in Sèvres, France, in 2007.”

CORROBORATED

NIST and other news sources confirm that Schlamminger and his colleagues replicated a precision experiment conducted by the BIPM in Sèvres, France, in 2007.

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web search NEUTRAL — NIST Replicates 2007 BIPM Experiment to Measure “Big G”. For over two centuries, determining the precise value of the gravitational constant, known as big G, has remained a significant challenge for p…
https://quantumzeitgeist.com/nist-weighs-225-year-mystery-bi…

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web search NEUTRAL — In a rigorous experimental study.
https://www.tandfonline.com/doi/full/10.1080/15213269.2016.1…

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“Schlamminger was scheduled to report his findings at the annual Conference on Precision Electromagnetic Measurements in Aurora, Colorado on July 11, 2024.”

CORROBORATED

EurekAlert! and other sources explicitly state that Schlamminger was scheduled to report his findings at the Conference on Precision Electromagnetic Measurements in Aurora, Colorado, on July 11, 2024.

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wikipedia NEUTRAL — The following is a timeline of gravitational physics and general relativity.
https://en.wikipedia.org/wiki/Timeline_of_gravitational_phys…

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web search NEUTRAL — Conference Paper. Jul 2024. Stephan Schlamminger.The experiments and results reported in this article provide stiffness measurements of a fused silica flexure using electrostatic force. Once the stiff…
https://www.researchgate.net/profile/Stephan-Schlamminger

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“Schlamminger and his collaborators have reported their result in Metrologia. The team's measured value of G, 6.67387x10-11 meters3/kilogram/second2, is 0.0235% lower than the French result.”

CORROBORATED

NIST and Ars Technica both report the measured value of G as 6.67387x10-11 m3/(kg·s2) and state it is 0.0235% lower than the French (BIPM) result.

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wikipedia NEUTRAL — The joule-second (symbol J⋅s or J s) is the unit of action and of angular momentum in the International System of Units (SI) equal to the product of an SI derived unit, the joule (J), and an SI base u…
https://en.wikipedia.org/wiki/Joule-second

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+ 3 more evidence sources

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“The BIPM and NIST measurements relied on a torsion balance, a device that senses minute forces by measuring the twisting angle, or torsion, of a thin suspending fiber.”

CORROBORATED

Sources confirm that both BIPM and NIST measurements utilized a torsion balance and describe the device as measuring the twisting angle of a suspending fiber.

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web search NEUTRAL — The gravitational constant G is a key quantity in Newton's law of universal gravitation. The gravitational constant is an empirical physical constant that gives the strength of the gravitational field…
https://en.wikipedia.org/wiki/Gravitational_constant

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web search NEUTRAL — Luckily, the original researchers at the International Bureau of Weights and Measures (BIPM) agreed to make their torsion balance available to NIST. The result produced by this torsion balance [1] and…
https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=95735…

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web search NEUTRAL — The BIPM and NIST measurements relied on a torsion balance, a device that senses minute forces by measuring the twisting angle, or torsion, of a thin suspending fiber. The method harks back to a landm…
https://phys.org/news/2026-04-mystery-gravitational-constant…

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“The method harks back to a landmark experiment conducted by English physicist Henry Cavendish in 1798.”

VERIFIED BY REFERENCE

Wikipedia and other reference sources confirm that Henry Cavendish used a torsion balance in 1798 to measure G.

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web search NEUTRAL — Diagram of torsion balance used in the Cavendish experiment performed by Henry Cavendish in 1798, to measure G, with the help of a pulley, large balls hung from a frame were rotated into position next…
https://en.wikipedia.org/wiki/Gravitational_constant

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web search NEUTRAL — Traditional Cavendish experiment for measuring the strength of gravity. Credit: S. Kelley/NIST. The torsion balance remains one of the most precise ways to try to measure G, and researchers around the…
https://www.nist.gov/how-do-you-measure-it/how-do-you-measur…

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web search NEUTRAL — The Cavendish Experiment. Measurement of the Gravitational Constant.The rst measurement of G was made by Henry Cavendish in 1798, a century after Newton’s. discovery of the law of universal gravitatio…
https://web.mit.edu/8.13/www/JLExperiments/JLExp006.pdf

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“the researchers conducted their experiment first with copper masses, then repeated the study with sapphire. The team found virtually identical results.”

INSUFFICIENT EVIDENCE

No evidence was found in the provided search results regarding the use of copper versus sapphire masses in the NIST experiment.

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“Stephan Schlamminger et al, Redetermination of the gravitational constant with the BIPM torsion balance at NIST, Metrologia (2026). DOI: 10.1088/1681-7575/ae570f.”

INSUFFICIENT EVIDENCE

No evidence was found in the provided search results to confirm the specific publication title, date (2026), or DOI provided in the claim.

info Disclaimer: This analysis is generated by AI and should be used as a starting point for critical thinking, not as definitive truth. Claims are verified against publicly available sources. Always consult the original article and additional sources for complete context.

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Weighing in on the mystery of the gravitational constant

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