11/05/2026
It might look like Charles-Augustin de Coulomb simply mirrored what Isaac Newton had already done, because both gravitational and electric forces follow an inverse-square form. But Coulomb did not copy Newton’s formula. Newton’s law of gravitation (published in 1687) established that masses attract with a force proportional to the product of their masses and inversely proportional to the square of the distance between them. Nearly a century later, Coulomb (in the 1780s) was investigating electric charge experimentally using a torsion balance, carefully measuring how charged objects interact. From these measurements, he independently determined that electric forces also follow an inverse-square dependence and are proportional to the product of the charges. The similarity between the two laws reflects a deeper physical principle rather than imitation. Both gravity and electrostatics are central forces that spread out uniformly in three-dimensional space, which naturally leads to a 1/r² dependence. The key differences are just as important: gravity depends on mass and is always attractive, while electric forces depend on charge and can be either attractive or repulsive. So while the equations look almost identical, they arise from separate phenomena and independent work
