A Preposterous Universe

Abstract

Recent announcements that the cosmic microwave background (CMB)-the faint remnant of the big bang-is polarized have caused a stir among cosmologists. As Gangui explains in his Perspective, such a polarization has long been predicted but could not be detected. The polarization is a signature of the motion of the primordial seeds that led to the galaxies and large-scale structure in the universe observed today. Earlier measurements of tiny temperature fluctuations in the CMB have been used to infer the sizes of the primordial seeds. The polarization signature should help to determine the fundamental parameters of cosmology and to explain how large-scale structure arose.