Model Maps From Boomerang
Boomerang measured the anisotropy in the Cosmic Microwave Background (CMB). The CMB are photons reaching us from the surface of last scattering. The color indicate the temperature of the region. Hot regions are red, and cold regions are blue. The temperature difference between hot and cold regions are 1/100,000 kelvin. Hot regions indicate regions of lower density, because the potential wells the CMB photons had to climb out of were shallower. Colder regions indicate higher density because the potential wells were deeper. The size of the regions indicate the geometry of the universe. To a first order, Boomerang results indicate that the universe is flat.
Type Ia supernova are standard candles with known absolute brightness. They allow distance calibrations, which enables us to look back in time. The Supernova data indicated that the expansion of the universe is accelerating, contrary to most modern theories to date. This prompted the revival of the "lambda" parameter, which is explained as a "vacuum energy", or the natural springiness of the universe. The Supernova data was able to constrain the relative ratios of the density of matter, and the density of the "lambda" parameter. The total density of the universe was the sum of these two densities. Boomerang was able to measure the sum of the densities and constrained it to be around one.
The best fit value to the Supernova and Boomerang data suggest that Omega Matter = 0.3, and Omega Lambda = 0.7. Omega Total = 1, and therefore the universe is FLAT.
For more cosmology, go to Ned Wright's Cosmology Tutorial
For more Boomerang information, go to their website
This page was last modified on May 19th, 2000