New study challenges Einstein and Newton's theories of gravity

Gravity is the force that pulls things towards the Earth and keeps planets orbiting the Sun in motion.

Isaac Newton first introduced the concept of gravity to science in 1687. Prior to Albert Einstein's 'General Theory of Relativity,' which filled in the gaps left by Newton's theory of gravity, Newton's theory of gravity had withstood the test of time for two centuries.

Although Einstein's theory of gravity's great accomplishments, many phenomena, like gravitational waves and the gravity within a black hole, remain unsolved.

Recent research has discovered concrete support for a revised theory of gravity at low acceleration. The research was conducted at Sejong University in Seoul, Korea, by Prof. Kyu-Hyun Chae. Chae used information gathered by the Gaia space telescope operated by the European Space Agency to study the orbital behaviors of cosmic objects known as broad binary stars.

These findings are important because they suggest an alternative to the Newton-Einstein theory of gravity.

Newton's & Einstein's theories of gravity:

At the time, Newton's theory of gravity was groundbreaking. It gave us a better grasp of how planets move through the solar system by effectively explaining the attraction between bodies on Earth and beyond.

Newton's framework, however, showed flaws in its capacity to explain intricate gravitational events as technology advanced. One of these was an anomaly in Mercury's orbit, which perplexed scientists and demonstrated that the theory fails to explain extremely strong gravitational fields.

The General Theory of Relativity was Einstein's magnum opus, which was then published in 1915. This revolutionary idea brought mass and energy together in a cosmic dance by reimagining gravity as the curvature of spacetime itself.

In addition to explaining how starlight bends around big things during a solar eclipse, Einstein's theory bridged Mercury's orbit. In the face of the cosmic abyss—black holes, where gravity becomes eternally intense—even Einstein's forward-thinking ideas fell short.

Scientists introduced the idea of dark matter to close these gaps. Since it doesn't interact with light, this elusive type of matter is unseen, yet its gravitational force allows us to observe its consequences. It was proposed as a theory to account for the differences between predicted and observed gravitational effects.

However, scientists are unsure about the nature of dark matter and whether it really exists.

MOND: Modified Newtonian dynamics:

Due to the dearth of evidence, several scientists have expressed pessimism about the notion that dark matter may explain differences. As a result, several theories have been developed.

Modified Newtonian dynamics (MOND), a theory developed by Israeli physicist Mordehai Milgrom, was first put up as a possible explanation for a number of galactic anomalies, including those identified by Chae, in 1983.

MOND's fundamental concept is that Newtonian gravity, which typically functions effectively in real-world conditions, can act differently at incredibly low accelerations.

It is proposed that this departure from Newtonian physics takes place when the gravitational fields are weak. According to MOND, the gravitational force no longer obeys the well-known inverse square rule but rather takes on a distinct functional form at these low accelerations.

In order to explain gravitational anomalies, such as galaxy orbital velocities, without the need for dark matter, MOND modifies Newtonian gravity.

It implies that acceleration depends on masses and a scale-dependent function, which is different from classical gravity in that it varies on the size or scale of the system being examined.

Wide binary star systems:

Within 650 lightyears, Chae examined 26,500 thorough binary star systems using the Gaia telescope's data.

Wide binary star systems are made up of two stars in relatively far-off orbits. According to Chae's analysis of these systems, the observed accelerations at ultra-low accelerations were 30–40% higher than conventional predictions, raising the possibility that regular gravity may have broken down.

A Quadratic LaGrange (AQUAL), a MOND-influenced theory of gravity co-authored by Milgrom, explains this unexpected acceleration increase, providing concrete proof that normal gravity breaks down at low acceleration.

Chae stated in a press release that he decided to research these systems because "from the start, it seemed clear to me that gravity could be tested most directly and efficiently by calculating accelerations because the gravitational field itself is an acceleration."

"I came up with this concept after my recent research with galactic rotation curves. Galactic discs and wide binaries have certain similarities in their orbits, but hydrogen gas particles in a galactic disc have approximately circular orbits, whereas wide binaries have substantially elongated orbits', he said.

Chae's research does more than just question the status quo; it also paves the way for a deeper investigation of gravity's secrets. He thinks that by using bigger and better data sets, his findings will be verified and improved.