Assam scientists probe Sun to rethink gravity

The Sun may be doing more than warming planet Earth. It may also be helping scientists rethink one of nature’s most fundamental forces.

Researchers at Tezpur University in north-central Assam have used observations of the Sun’s internal movements to test a new concept on the nature of gravity, marking a step towards understanding the hidden physics within the primary energy source of the solar system and other stars like it.

The study, conducted by Pralay Kumar Karmakar of the Department of Physics and Souvik Das, a researcher under the DST-INSPIRE programme, examines how gravity behaves under the Sun’s extreme heat and pressure. The research has been accepted for publication in Physical Review E, an international journal of the American Physical Society.

DST-INSPIRE refers to the Department of Science and Technology’s Innovation in Science Pursuit for Inspired Research programme.

Deep inside the Sun, hot gas moves in waves, carrying energy and helping the star remain stable. For decades, scientists have studied these waves using traditional ideas of gravity developed by Isaac Newton. The Tezpur University team posed a question on whether gravity could behave differently under such extreme conditions.

To explore this, the researchers studied a modified theory of gravity known as the Eddington-inspired Born-Infeld (EiBI) gravity and compared their calculations with four years of observational data collected by NASA’s Solar Dynamics Observatory. They found that even small changes in gravity could significantly affect how energy moves inside the Sun, increasing wave speeds and stability by up to 55%.

The study also showed that some subtle gravity-driven movements inside the Sun, earlier considered insignificant, may carry a substantial amount of energy. Most notably, the results closely matched actual solar observations, making this among the first instances of the gravity model being tested using data from within a star.

“Our findings show that the Sun itself can act as a natural laboratory. Tiny changes in gravity can have noticeable effects on how the Sun’s interior moves and stays stable,” Mr. Das, the lead author, said.

Prof. Karmakar said the research highlights the value of studying the Sun to address broader questions in physics. “By listening to the Sun’s internal vibrations, we can test ideas that go beyond traditional theories of gravity,” he said.

The findings not only deepen the understanding of the Sun but also open possibilities for studying gravity elsewhere in the universe by using stars themselves as observational guides.