Researchers at ETH Zurich have redetermined the gravitational constant G using a new measurement technique. Although there is still a large degree of uncertainty regarding this value, the new method offers great potential for testing one of the most fundamental laws of nature.

The gravitational constant G determines the strength of gravity — the force that makes apples fall to the ground or pulls the Earth in its orbit around the sun. It is part of Isaac Newton’s law of universal gravitation, which he first formulated more than 300 years ago. The constant cannot be derived mathematically; it has to be determined through experiment. [1]

Figure 1. The Scientists remeasured gravitational constant

Figure 1 shows Scientists made the first beam to vibrate. The gravitational coupling caused the second beam to exhibit minimal movement. They then used laser devices to measure the motion of the two beams. Measuring this dynamic effect allowed scientists to determine the magnitude of the gravitational constant.

Scientists found that value 2.2 percent higher than the current official value given by the Committee on Data for Science and Technology. Although, the new value is subject to a great deal of uncertainty. [2]

A novel experiment in an old fortress

To rule out sources of interference as far as possible, Dual's team set up their measuring equipment in what used to be the Furggels fortress, located near Pfäfers above Bad Ragaz, Switzerland. The experimental setup consists of two beams suspended in vacuum chambers. After the researchers set one vibrating, gravitational coupling caused the second beam to also exhibit minimal movement (in the picometre range -- i.e., one trillionth of a metre). Using laser devices, the team measured the motion of the two beams, and the measurement of this dynamic effect allowed them to infer the magnitude of the gravitational constant. [3]

Insight into the history of the universe

For Dual, the advantage of the new method is that it measures gravity dynamically via the moving beams. “In dynamic measurements, unlike static ones, it doesn’t matter that it’s impossible to isolate the gravitational effect of other bodies,” he says. That’s why he hopes that he and his team can use the experiment to help crack the gravity conundrum. Science has still not fully understood this natural force or the experiments that relate to it. [4]

References:

1. https://vervetimes.com/researchers-remeasure-gravitational-constant-sciencedaily/
2. https://www.techexplorist.com/scientists-remeasured-gravitational-constant/52466/
3. https://www.sciencedaily.com/releases/2022/07/220712102703.htm
4. https://ethz.ch/en/news-and-events/eth-news/news/2022/07/eth-researchers-remeasure-gravitational-constant.html

Cite this article:

Thanusri swetha J (2022), Scientists remeasured gravitational constant, Anatechmaz, pp.147