Einstein’s Theory of Gravity Confirmed Once More
More than a century ago, in 1915, genius scientist Einstien realized that his then recently-formulated general theory of relativity explained an odd occurrence in the orbit of Mercury. Fast forward to the present day, and that same effect has been observed in a star’s orbit around the enormous black hole that’s situated at the heart of the Milky Way.
The star is called S2 and is part of a stellar entourage that surrounds the central supermassive black hole of the Milky Way. Before tracking its elliptical motion, researchers previously used the star to identify another effect of general relativity known as gravitational redshift — the reddening of a star’s light.
The rosette-shaped path of S2 around the supermassive black hole confirms Einstein’s theory of gravity because instead of tracing out a single ellipse (marked in red in the picture), the star’s orbit actually rotates over time (marked in blue for emphasis). This elliptical motion over time is known as the Schwarzschild precession. According to general relativity, that precession occurs when there is a warping of spacetime caused by massive objects. A similar precession was observed in Mercury’s orbit even before Einstein came along.
In Search for a New and Improved Theory of Gravity
Although physicists are yet to find a case where general relativity falls flat, they haven’t stopped searching for cracks in the theory in the hope of formulating a new, improved theory of gravity. This most recent study of S2 is yet another proof that Einstein’s theory is correct, even in an environment of intense gravity around a supermassive black hole.