Curiosities: Did general relativity replace Newton’s gravity?

In the early 20th century, Albert Einstein’s theory of general relativity revolutionised our understanding of gravity, but did it truly replace Isaac Newton’s timeless laws?

Newton’s law of universal gravitation described gravity as a force acting between masses over a distance. For over 200 years, his work enabled astronomers to explain the elliptical orbits of planets around the sun, the influence of the moon’s gravity on tides, the trajectories of comets and even the discovery of Neptune.

However, an anomaly in Mercury’s orbit could not be accounted for using Newtonian physics. Einstein proposed that, rather than being a force, gravity is a consequence of massive objects, like planets, warping the fabric of spacetime around them. This theory not only explained Mercury’s orbital irregularities but was further validated when observations confirmed that light bends as it passes near a massive object.

Was Newton’s theory incorrect? Newton’s theory of gravitation continues to be widely applied in science, engineering and technology today. It plays a crucial role in everything from the architectural design of large structures, to detecting gravitational anomalies that reveal geological formations, to the engineering behind spacecraft launches and landings.

While Newton’s theory is highly effective, it has limitations when it comes to high-precision calculations in extreme conditions, such as near black holes or at the speed of light.