In 1915, Albert Einstein published his theory of general relativity which describes the nature of gravity and its effect on large objects in space. Since then, this work has formed the bedrock of scientists’ understanding of our universe.
But despite its importance, general relativity is not the only explanation for the workings of gravity. In fact, various scientists have proposed alternative theories over time.
Now, a team of scientists from the University of Durham, U.K., has published a study in the journal Nature Astronomy which suggests that one of these alternative theories (chameleon theory) could actually explain how gravity works in some situations.
The research could also help further understanding of dark energy—the mysterious substance that is accelerating the expansion rate of the universe.
For their study, the team ran advanced supercomputer simulations which showed that galaxies could still form in a universe where the principles of chameleon theory applied.
“What we have found is that realistic galaxies like our Milky Way can form, with properties as observed, even with the complicated behavior of the fifth force—this is by no means guaranteed,” Li said. “It also shows that chameleon theory can make certain distinct predictions on the evolution of the large-scale structures in the universe from general relativity.”
“Through our simulations we have shown for the first time that even if you change gravity, it would not prevent disc galaxies with spiral arms from forming.
“Our research definitely does not mean that General Relativity is wrong, but it does show that it does not have to be the only way to explain gravity’s role in the evolution of the universe.”
The Durham researchers expect their findings can be tested through observations using the Square Kilometre Array (SKA) telescope, based in Australia and South Africa, which is due to begin observations in 2020.
SKA will be the world’s largest radio telescope and aims to challenge Einstein’s theory of General Relativity, look at how the first stars and galaxies formed after the Big Bang, and help scientists to understand the nature or dark energy.