GRAVITATION

Of all forces in nature, gravity is the most familiar yet the most mysterious. We experience it every moment—objects fall, we remain grounded, planets orbit the sun. Yet gravity acts across vast distances, without contact, with an intensity that decreases gradually with separation. Newton's revolutionary insight was that the same force pulling an apple to Earth holds the moon in orbit and keeps planets around the sun. This unified terrestrial and celestial phenomena into a single mathematical framework. Gravitation governs the motion of planets, formation of galaxies, and structure of the cosmos. Understanding gravity requires developing the concept of gravitational field, gravitational potential energy, orbital mechanics, and the nature of escape velocity. This chapter explores gravitation as a fundamental interaction, its mathematical description, and its consequences for motion in space and on Earth.

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