Why does gravitational force decrease as the distance between objects increases?

According to Isaac Newton, the gravitational force between two objects decreases as the distance between them increases because it follows an inverse square law.12

In his law of universal gravitation, Newton established that the magnitude of the attractive force ($F$) is directly proportional to the product of the masses of the two objects ($m_1$ and $m_2$) and inversely proportional to the square of the distance ($R$) between them. This relationship is expressed as:12

$$F=G\frac{m_1{m}_2}{R^2}$$

Because the distance is squared in the denominator, the force weakens rapidly as objects move apart. For example, if the distance between two bodies is doubled, the gravitational force between them is reduced to one-fourth of its original strength. Newton derived this principle by observing the motion of the Moon and comparing its acceleration to that of objects falling freely on Earth, confirming that the same gravitational interaction governs both terrestrial and celestial bodies.2