Iò??ve read about background radiation fields that fill the universe. Is the infrared radiation as ancient as the microwave, and are there other cosmic fields of radiation besides these two?
Nicholas Weeks, Moorpark, California
Published: Monday, April 23, 2012
The cosmic background radiation currently emits mainly at microwave wavelengths. The cosmic background radiation used to have a shorter wavelength (higher energy) when the universe was younger and smaller. When the universe was 1 million years old, the cosmic background was mostly infrared radiation. Today we observe photons emitted from stars and galaxies in the cosmos at all frequencies.