🕰️ Relativity — Advanced#

Scope — General relativity, gravity as geometry, and relativistic effects in cosmology and astrophysics.

Key concepts#

• General relativity — gravity described as curvature of spacetime caused by mass and energy.
• Equivalence principle — local equivalence of gravitational and inertial effects.
• Geodesics — paths objects follow in curved spacetime.

Seed Q&A triads#

• Q: How does general relativity reinterpret gravity?
  A: As the curvature of spacetime guiding the motion of matter and light.

• Q: What is the equivalence principle?
  A: The idea that gravitational and inertial effects are locally indistinguishable.

• Q: Why is relativity essential for modern cosmology?
  A: It governs large‑scale structure, black holes, gravitational waves, and cosmic expansion.

Contributor prompts and extensions#

• Add a worked example illustrating gravitational time dilation near a massive object.
• Include a short discussion of experimental tests of general relativity.
• Connect relativity to cosmology, black holes, and gravitational wave astronomy.

Advanced exercises#

• Analyze how spacetime curvature alters light paths near massive bodies.