) is now a faint glow 2.7 degrees above absolute zero.
It was speculated that the CMB was like a 'blackbodyÆ spectrum, like the light an object radiates because of its thermal energy (Seife 2237). It was also speculated that it would bear the marks where lumps of matter oscillated before the universe cooled and freed the light. These acoustic oscillations should show as hot spots, but nobody had a way of measuring them. In 1990, the Cosmic Background Explorer (COBE) satellite confirmed that the cosmic background spectrum was blackbody radiation, but it could not see features smaller than a few degrees. Finally, in 2000, the BOOMERANG balloon experiment saw the one degree hot spots showing up as a peak on a graph, and from the size of the spots, scientists concluded that the universe was flat in a four-dimensional sense rather than curved. The Cosmic Background Imager, MAXIMA, and the Degree Angular Scale Interferometer found evidence of two more peaks, confirming the acoustic-oscillation model of the early universe and revealing the contents of the cosmos. Scientists have calculated from the relative sizes of the first and second peaks that baryonic ordinary matter, of which people and stars are made, makes up four percent of the energy and matter in the universe Seife 2238).
Scientists are now measuring the amount of dark matter and dark energy in the universe, and looking at the polarization of the light as it was finally released from the cooling universe (Seife 2238). As the CMB scattered the photons into space, it polarized them, and by studying the angles of the polarization of the CMB, scientists can calculate where the photons were bouncing from, which reveals how matter was distributed in the early universe. Using polarized light, scientists should also be able to look at what happened one billion years ago, when stars, galaxies, and quasars were formed, and electrons were stripped from atoms once again. This...