The physical universe is enormously complex in its detail. Every day, each of us observes a great variety of objects and phenomena. Over the
centuries, the curiosity of the human race has led us collectively to explore and catalog a tremendous wealth of information. From the flight of birds to
the colors of flowers, from lightning to gravity, from quarks to clusters of galaxies, from the flow of time to the mystery of the creation of the universe,
we have asked questions and assembled huge arrays of facts. In the face of all these details, we have discovered that a surprisingly small and
unified set of physical laws can explain what we observe. As humans, we make generalizations and seek order. We have found that nature is
remarkably cooperative—it exhibits the underlying order and simplicity we so value.