The Cosmic Microwave Background
¥Cosmic Microwave Background (CMB) is an ÒechoÓ of the Big Bang.
¥Small anisotropies (less than 1 part in 100000) in CMB can be analyzed to learn about very early universe.
¥In theory, we can just point our radio telescopes at the sky and measure the CMB.
The COBE map of the universe.
Angular power spectrum of the CMB