Cosmic Background Radiation and the Expanding Universe
This simple animation illustrates the effect expansion of the Universe has on the cosmic background
radiation. Expansion dilutes the number density of the photons and redshifts them, producing the
change in spectrum indicated schematically
by the animation. The spectrum remains blackbody, but is lowered in
intensity and redshifted to the microwave region of the spectrum by the expansion.
Usage:
Click "Play" to begin.
"Step" moves forward one step and "Back" moves backwards one step.
"Home" returns to the beginning from any point.