---
tags:
  - science/physics
  - phenomena
  - gravity
  - newton
  - einstein
created: 2026-05-16
breadcrumb: "Physics > Natural phenomena > Gravity"
---

# Gravity

> **Mechanism:** Attractive force between masses (or curvature of spacetime)

## Items

- **Newton's law** — F = G m₁m₂ / r². G ≈ 6.674 × 10⁻¹¹ N·m²/kg².
- **Surface gravity** — g ≈ 9.81 m/s² on Earth.
- **Orbital motion** — Closed orbit when KE + PE < 0. Kepler's third: T² ∝ a³.
- **Tides** — Differential gravity of the Moon (and Sun) deforms ocean shape.
- **General relativity view** — Mass-energy curves spacetime; objects follow geodesics.

## Related

- [[relativity]]
- [[newtons-laws]]