Measuring Gravity Is Super Hard

Weighing in on the mystery of the gravitational constant

Here is told the wonderful story of a recent attempt to measure the gravitational constant G.

Although experiments have become more sensitive and sophisticated, many recent measurements of big G have had slightly different values. Although the differences are slight, about one part in 10,000, they are still too large to be explained by routine experimental errors.

That disparity had created an unsettling mystery. Is there some overlooked experimental error causing the mismatches—the most likely explanation—or is there something fundamentally wrong with our understanding of gravity?

That's what 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. If Schlamminger could independently reproduce the same results of that study at NIST's campus in Gaithersburg, Maryland, the mystery might be resolved.

One of the beautiful things about this attempt to measure G is that it is a replication of an earlier experiment. One could say that replicability, reproducibility, and repeatability are the three Rs of experimental science. Taking anything in science on faith is a major error.

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Author: Flower Snark
Email: flowersnark@gmail.com

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Page created on 2026-04-21T19:46:21-04:00.