Big Bang Expansion Timeline
Interactive 3D-style canvas simulation: Big Bang Expansion Timeline.
Scale factor a1.000
CMB temperature2.7 K
Matter-dominated eraa ∝ t²ᐟ³
The wireframe sphere is comoving space — every galaxy stays at the same comoving coordinate while the scale factor a(t) grows. Streaks show recession speed: farther galaxies recede faster (Hubble’s law).
Concepts in this lab
scale factorhubble lawcmb cooling
Connected topic
Open lessonDiscovery of cosmic expansion
A complete introduction to Discovery of cosmic expansion within Modern discovery history, linking observations, physical models, history and modern applications.