Figure 1
Credit: Top, NASA LAMBDA; Bottom, Courtesy of the WMAP Science Team/Astrophys. J. Suppl. [1].

Figure 1: (Top) A sky map of the universe 13.7 billion years ago. The different colors correspond to temperature fluctuations (+/-200 milliKelvin) in the cosmic microwave background. (Bottom) A convenient way to analyze this data is to take an angular spherical harmonic transform. The resulting temperature power spectrum is plotted against the order of the spherical harmonic. (The legend indicates the different collaborations that contributed to the data.)