Who Discovered Gravity?

What did Newton actually discover about gravity?

Newton proposed that every object in the universe attracts every other object with a force proportional to their masses and inversely proportional to the square of the distance between them. The famous apple story may or may not be true (Newton himself told versions of it later in life), but the insight that the same force pulling apples down also keeps the moon orbiting Earth was revolutionary. His formula F = Gm₁m₂/r² predicted planetary motion with remarkable accuracy and unified earthly and celestial physics for the first time. Newton's broader scientific work and his role in the scientific revolution are documented in Britannica's biography of Isaac Newton.

Did anyone study gravity before Newton?

Yes. Galileo Galilei in the early 1600s showed that all objects fall at the same rate regardless of mass, contradicting Aristotle's older view. Johannes Kepler described how planets move in elliptical orbits around the sun, providing the data Newton would later explain. Robert Hooke even discussed an inverse-square law for gravity before Newton published, leading to a bitter priority dispute. Newton's real contribution was unifying these observations into one mathematical theory that worked for both terrestrial and astronomical motion.

How did Einstein change our understanding of gravity?

Albert Einstein published the general theory of relativity in 1915, proposing that gravity is not really a force at all, but a curvature in spacetime caused by mass and energy. Massive objects like the sun bend the fabric of spacetime around them, and other objects follow these curves. Einstein's theory explained anomalies Newton's equations could not, like the precession of Mercury's orbit, and predicted phenomena like black holes, gravitational lensing, and gravitational waves, all later confirmed by observation.

Is gravity still being discovered?

Active research continues. Scientists confirmed gravitational waves in 2015 using the LIGO detector, proving Einstein right a century later. Quantum gravity, which would unify Einstein's general relativity with quantum mechanics, remains one of the great unsolved problems in physics. Dark matter and dark energy hint that we still do not fully understand how gravity behaves at the largest scales of the universe. The discovery story of gravity is not finished yet.