The size of this feature’s uniformities is determined by the extent of Silk damping. (10[1])The BOOMERanG and MAXIMA experiments both imaged this feature with a balloon at an altitude of 40 kilometers. This feature’s polarization is divided into E- and B-modes. (10[2])The Sachs–Wolfe effect induces (10[1])anisotropies (“an-eye-SAW-truh-peez”) in this feature from gravitational redshift at the surface of last scattering. A void in the constellation Eridanus is an explanation of a “cold spot” in this feature (10[1])that was observed (10[1])by the COBE (10[1])(“KO-bee”) and Planck (10[1])satellites. Arno Penzias and Robert Wilson discovered this feature after making sure it wasn’t interference from bird poop on their antenna. This feature has a near-perfect blackbody spectrum at about 2.7 kelvins. For 10 points, name this leftover radiation from the Big Bang. (10[1])■END■