Scientists have proven that Einstein’s general theory of relativity is correct with a remarkable degree of accuracy, even though it has been around for more than a century.
The team behind the research wanted to test a component of Einstein’s general theory of relativity It’s called the weak equivalence principle, which states that all objects, regardless of mass or composition, must fall evenly into a given gravitational field when interference from factors such as atmospheric pressure is removed. To do this, scientists measured the acceleration of falling objects on a French satellite called Microscope, launched in 2016.
One of the most famous tests of the weak equivalence principle occurred during a Apollo 15 walking on the moon, when astronaut David Scott threw a feather and a geological hammer at the same time; Without air resistance, the two objects would accelerate toward the surface of the moon at the same rate. In a similar fashion, the microscope holds free-fall test blocks made from an alloy of platinum and titanium. Electrostatic forces hold the test masses in the same relative positions to each other, so any resulting difference in this applied electrostatic force must be a result of deviations in the acceleration of the objects.
Related: Why are physicists so determined to prove Galileo and Einstein wrong?
The team’s results, the culmination of 20 years of research, found that the acceleration of the pairs of freely falling objects did not differ by more than one part in 10^15, or 0.000000000000001, meaning they found no violation of the weakest. greater equivalence principle. What is this.
In addition to placing limitations on deviations from the weak equivalence principle, the results also reject any deviations from Einstein’s 1915 theory. gravity, General Relativity, as a whole. Scientists continue to search for such anomalies because general relativity, our best description of gravity, is inconsistent with quantum physics, our best model of reality at incomprehensible small scales.
So, no sign of aberration still means no hint of extensions to general relativity waiting to be found that could bridge the gap with quantum physics.
“We have new and much better constraints for any future theory because these theories should not violate the equivalence principle at this level,” said Gilles Mitris, a member of the MICROSCOPE team and a scientist at the Observatoire de la Côte. . statement (Opens in a new tab) From the American Physical Society that published the research.
MICROSCOPE was launched in April 2016 and the mission crew released their preliminary findings in 2017. Data analysis continued to make sense even after the experiment ended in 2018.
The fact that the new research did not find any violation of the weak equivalence principle puts the highest stress to date on this element of general relativity, and the results also lay the groundwork for more sensitive tests to come.
That’s because the scientists included suggestions on how to improve the experimental setup they used. They wrote that potential improvements include reducing defects in satellite coatings that could affect accelerometer measurements as well as replacing wired systems with those using wireless connections.
A satellite implementing these improvements can detect violations of the weak equivalence principle as small as one part in 10^17, 100 times more sensitive than MICROSCOPE. But the team expects that these improvements will not be achievable for some time, which means that for now the MICROSCOPE experiment will remain the best test of the weak equivalence principle.
“For at least a decade or maybe two decades, we won’t see any improvement in the space satellite experience,” said Manuel Rodriguez, a member of the MICROSCOPE team and a scientist at ONERA, a French research institute specializing in space. Press release. .
The team’s research was published Wednesday, September 14 in the journal Physical Examination Letters (Opens in a new tab) And a special number of “Classical and Quantum Gravity”.
Follow us on Twitter @Espacedotcom and on FB.