Within a tiny fraction of a second, the big bang inflated the universe. Compression waves created a pattern in the afterglow of the expansion, known as the cosmic microwave background, which scientists have studied and mapped since the 1960s. In the 1990s, physicists theorized that rapid inflation during the big bang would also generate gravity waves, which would leave their mark by polarizing light in the cosmic afterglow. Extremely sensitive telescopes at the South Pole have detected such skewed light waves, but scientists have spent almost a decade ensuring that the phenomenon was not the result of other factors. Compression waves Big bang Cosmic microwave background Lines indicate orientation and degree of polarization Gravity waves

SOURCE: Harvard-Smithsonian Center for Astrophysics.