ABSTRACT
The physical sciences tell a different story, one that is more difficult for people to grasp. According to astrophysicists who study the early universe, the earth, which is our home, is a fairly small and insignificant planet in the Milky Way galaxy. In turn, the Milky Way is only a minor galaxy in a universe that is unthinkable in its vastness. The exact age of the universe is still being studied-by looking at the oldest stars or by measuring the rate of expansion-but scientists at the National Aeronautics and Space Administration (NASA), using its Wilkinson Microwave Anisotropy Probe (WMAP), pegged the age of the universe
at 13.7 billion years (NASA/Goddard Space Flight Center, 2010; see also the Web site on mysearchlab.com ). This research is part of cosmology, the study of the origin and evolution of the universe, a pioneering science that holds the promise for scientists to converge toward facts, despite limits.
