CAPMAP - Measuring the Polarization of the Cosmic Microwave Background
 
The photons of the cosmic microwave background (CMB) are the oldest light 
in the universe and provide us with a direct and unique view of the
infant universe 300,000 years after the big bang. Its characteristics
contain detailed information about the history of the universe and allow
precise tests of current models of the development of the universe.
Several experiments have already measured the tiny anisotropies of the CMB
temperature of 1 part in 100,000. Its polarization is predicted
to be even one order of magnitude smaller, which makes its measurement a
big experimental challenge. In fact, it escaped detection until DASI 
reported its detection in September 2002.
Various experiments using different techniques are underway to measure
the detailed spectrum of the polarization and through that get an
independent determination of relevant cosmological parameters.
 
The CAPMAP experiment will measure the polarization of the CMB at 
90 GHz using a radio telescope in New Jersey. The installation
of the experiment has started and data taking with a partial setup will
begin this winter. The first results are expected next year.