---
tags:
  - science/physics
  - laws
  - relativity
  - einstein
created: 2026-05-16
breadcrumb: "Physics > Laws of physics > Special & general relativity"
---

# Special & general relativity

> **Mechanism:** Symmetry of spacetime under transformations

## Items

- **SR postulate 1** — The laws of physics are the same in all inertial frames.
- **SR postulate 2** — The speed of light in vacuum, c, is the same for all observers regardless of motion.
- **Time dilation** — Moving clocks tick slower by a factor γ = 1/√(1 − v²/c²).
- **Mass-energy** — E² = (mc²)² + (pc)². For a body at rest: E = mc².
- **General relativity** — Gravity is the curvature of spacetime caused by mass-energy. G_µν = 8πG T_µν / c⁴.

## Related

- [[famous-physics-equations]]