{"id":92595,"date":"2026-05-07T19:41:57","date_gmt":"2026-05-07T19:41:57","guid":{"rendered":"https:\/\/diyhaven858.wasmer.app\/index.php\/gravity-holds-the-universe-together-a-decade-long-experiment-has-failed-to-pin-down-its-numerical-value\/"},"modified":"2026-05-07T19:41:57","modified_gmt":"2026-05-07T19:41:57","slug":"gravity-holds-the-universe-together-a-decade-long-experiment-has-failed-to-pin-down-its-numerical-value","status":"publish","type":"post","link":"https:\/\/diyhaven858.wasmer.app\/index.php\/gravity-holds-the-universe-together-a-decade-long-experiment-has-failed-to-pin-down-its-numerical-value\/","title":{"rendered":"Gravity holds the universe together. A decade-long experiment has failed to pin down its numerical value"},"content":{"rendered":"
\n<\/p>\n
\n
Scientists have announced the results of a decade-long quest to measure Newton\u2019s gravitational constant, the force that keeps our feet on the ground and holds planets in orbit.<\/p>\n
The pursuit was more or less a bust. The most ambitious effort to date to pin down the fundamental constant, which determines the strength of the attraction between two masses anywhere in the universe, resulted in a number that disagreed with previous findings, including the results of an experiment it sought to replicate.<\/p>\n
Stephan Schlamminger, the scientist who painstakingly conducted the latest experiment that began in 2016, called it a \u201clife-sucking\u201d experience. \u201cIt was really kind of walking through a dark valley,\u201d added Schlamminger, a physicist at the National Institute of Standards and Technology in Gaithersburg, Maryland.<\/p>\n
But he has since been able to put a positive spin on his endeavors. \u201cNow, I\u2019ve put it a little bit in my rearview mirror,\u201d he said. \u201cI think every measurement is an opportunity to learn and every measurement brings light into this darkness.\u201d<\/p>\n
What is the gravitational constant?<\/h3>\n
Fundamental constants of nature are key values that define the behavior of physical phenomena in the universe \u2014 and they don\u2019t change regardless of where you are in time or space. They include the speed of light and Planck\u2019s constant, which plays a key role in quantum physics.<\/p>\n
These constants are \u201cbaked into the fabric of the universe,\u201d Schlamminger said. \u201cIt\u2019s quite beautiful, because they are the same over generations. If you ever talked to an extraterrestrial, they would have the same concept.\u201d<\/p>\n
For more than 225 years, scientists have tried to measure the gravitational constant, nicknamed Big G. British scientist Henry Cavendish performed the first experiment to measure it in 1798, more than a 100 years after Isaac Newton first discovered the force of gravity.<\/p>\n
Scientists have not, however, been able to converge on a measurement with a level of precision comparable to that of constants such as the speed of light (299,792,458 meters per second) or Planck\u2019s constant, which is known to eight decimal places.<\/p>\n
The Committee on Data of the International Science Council, or CODATA, issues recommended values of fundamental physical constants. Its recommended numerical value for Big G is a four digit number with a measurement uncertainty of 22 points per million.<\/p>\n
Given that other constants in nature are known to six or more significant digits and are considered exact, this value, he said, is an \u201cembarrassment for the active metrologist,\u201d a scientist who specializes in measurements.<\/p>\n
\u201cIf you had a watch that runs 22 ppm late, you would measure the year 12 minutes too long,\u201d he added.<\/p>\n
The field of metrology \u2014 the science of measurement \u2014 is important, he noted, because it creates trust in science, the economy and trade. \u201cIt is the kind of the science that undergirds a lot of our society, and nobody notices,\u201d he said.<\/p>\n
\u201cWhen you pay your electricity bill, you want to make sure that you pay the right amount, right? There are people who know how to measure voltages and how to measure currents and how to measure power.\u201d<\/p>\n\n