Scientists have announced the results of a decade-long quest to measure Newton’s gravitational constant, the force that keeps our feet on the ground and holds planets in orbit.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.Stephan Schlamminger, the scientist who painstakingly conducted the latest experiment that began in 2016, called it a “life-sucking” experience. “It was really kind of walking through a dark valley,” added Schlamminger, a physicist at the National Institute of Standards and Technology in Gaithersburg, Maryland.AdvertisementAdvertisementBut he has since been able to put a positive spin on his endeavors. “Now, I’ve put it a little bit in my rearview mirror,” he said. “I think every measurement is an opportunity to learn and every measurement brings light into this darkness.”What is the gravitational constant?Fundamental constants of nature are key values that define the behavior of physical phenomena in the universe — and they don’t change regardless of where you are in time or space. They include the speed of light and Planck’s constant, which plays a key role in quantum physics.These constants are “baked into the fabric of the universe,” Schlamminger said. “It’s quite beautiful, because they are the same over generations. If you ever talked to an extraterrestrial, they would have the same concept.”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.AdvertisementAdvertisementScientists 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’s constant, which is known to eight decima …
