Prompt:
Write a Manim script to visualize spacetime curvature caused by a massive object, such as a planet or star.

Animation Concept:
• The animation should depict a 3D grid or a mesh plane representing spacetime.
• A massive object (e.g., a sphere) is placed at the center of the grid.
• The grid should warp downward around the object to simulate spacetime curvature.
• Optionally, show test particles (small dots or spheres) moving around the curved space to demonstrate how objects follow geodesics.
• The grid should smoothly animate from flat space to a curved surface as the mass is introduced.

Technical Details:
• Use Manim’s 3D capabilities (ThreeDScene).
• Implement a parametric surface to represent the warped spacetime.
• Animate the gravitational well formation over time.
• Use camera rotations to provide a clear perspective.
• Optionally, add labels (e.g., "Spacetime," "Mass," "Geodesics") and vector arrows to indicate force or curvature.

Extra Features (Optional):
• Show multiple masses (binary stars or planets) and their combined spacetime effect.
• Add light rays bending around the mass to demonstrate gravitational lensing.
• Display Einstein’s field equations briefly before the visualization.
• Animate the transition from Newtonian gravity (flat grid with attraction forces) to General Relativity (warped grid).