🌌 Cosmology — Intro#

Scope — The large‑scale structure, origin, and evolution of the universe as a whole.

Key concepts#

• Cosmology — branch of physics studying the universe’s overall properties, history, and fate.
• Expansion of the universe — galaxies recede from one another as space itself expands.
• Cosmic scale — distances and times far beyond everyday or planetary scales.

Seed Q&A triads#

• Q: What distinguishes cosmology from astronomy?
  A: Astronomy studies individual objects; cosmology studies the universe as a unified system.

• Q: What does it mean that the universe is expanding?
  A: Space between galaxies increases over time, causing distant galaxies to appear to move away from us.

• Q: Why is light important in cosmology?
  A: Light carries information across vast distances, allowing us to observe the universe’s past.

Quick activities#

• Compare distances within the solar system to distances between galaxies to appreciate cosmic scale.