If gravity is intrinsically so weak compared to the strong force, why do we say that gravity rather than the strong force keeps the planets in orbit around the Sun?

Understanding the fundamental forces in physics is essential to grasp why celestial bodies behave the way they do. These forces are the essential building blocks that govern the interactions among particles and objects in the universe. There are four recognized fundamental forces: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force.

Gravity is the most familiar to us, as it affects everyday objects, making apples fall from trees and keeping our feet on the ground. Its reach is limitless, and it acts on all objects that have mass and energy. While gravity is the weakest of the fundamental forces, its strength comes effectively into play over large distances. Electromagnetism, on the other hand, is responsible for the forces between electrically charged particles, giving rise to phenomena like light and electricity.

The strong and weak nuclear forces act at the atomic level, the former binding protons and neutrons in the nucleus and the latter being responsible for radioactive decay. The realm of these forces is minuscule compared to that of gravity and electromagnetism. Hence, while the strong nuclear force is indeed stronger than gravity, it does not influence celestial bodies due to its incredibly short range.

The strong nuclear force is vital for the stability of matter at the smallest scales. It holds together the particles within the nucleus of an atom, which are protons and neutrons, and is the fundamental force behind the power of the sun and other stars. This force operates through the exchange of particles called gluons and is incredibly strong, but only over short distances—about the diameter of an atomic nucleus.

Despite its name, the strong nuclear force is not the one keeping satellites in orbit or forming galaxies. Its strength is impressive, as it can overcome the repulsion between positively charged protons, but it diminishes rapidly beyond the size of the nucleus. In contrast, gravity plays no role in holding a nucleus together; its impact at such scales is negligible. As the strong force works over such a tiny range, it doesn't affect the motion of planets or their paths around the sun.

The majestic dance of celestial bodies through space is governed primarily by gravity, a force that persists over vast distances and through the vacuum of space. When we observe planets circling a star like our Sun, or moons orbiting their planets, gravity is the force at play.

An orbit is the result of an object moving forward while at the same time being pulled toward another larger body by gravity. This creates a balance between the forward motion and the inward pull, leading to a curved path around the larger body. Due to gravity's infinite range and the considerable mass of celestial bodies, it becomes the dominant force that dictates their orbits.

It is worth noting that while gravity is weak compared to the strong nuclear force, it acts on a completely different scale. Its influence on celestial motion is unmatched, making it the force responsible for keeping the planets, including Earth, in their paths around the Sun.