Question: User: Visual Prompt for AI Video Generator:Prompt: A high-tech 3D animation showing Earth suspended in space. Glowing blue field vectors converge radially inward from all directions towards Earth's core, illustrating a radial gravitational field ($g = GM / r^2$). Zooming in extremely close to a small region near the surface shows the field lines becoming straight, parallel, and evenly spaced, forming a uniform gravitational field where $g \approx 9.81\text{ N/kg}$. Glowing mathematical overlays show the inverse-square drop in field strength as distance doubles.English Voiceover & Text:Voiceover: "Gravitational fields represent non-contact forces acting on mass. Around spherical bodies, the field is radial, obeying the inverse-square law $g = GM / r^2$. Doubling your distance from the center reduces gravity to one-fourth. Close to Earth's surface, field lines become parallel and uniform, letting us treat $g$ as a constant $9.81\text{ N/kg}$."