Isotropy and Homogeneity of the Universe from Measurements of the Cosmic Microwave Background

Abstract

A Dicke radiometer (3.2-cm wavelength) was used to make daily scans near the celestial equator to look for possible anisotropy in the cosmic blackbody radiation. After about one year of intermittent operation we find no 24-h asymmetry with an amplitude greater than \ifmmode\pm\else\textpm\fi{}0.1% (of 3\ifmmode^\circ\else\textdegree\fi{}K). There is, however, a possibly significant 12-h anisotropy with an amplitude of about 0.2%.