Introduction to the Series

Astronomy has witnessed an unprecedented revolution during the past sixty years or so. During the last century, 'new windows to the Universe' opened up. One can now observe the sky at a wide spectrum of wavelengths - Radio waves, Millimeter waves, Infrared, Visible, Ultraviolet, X-rays and Gamma Rays; the advent of space age, as well as dramatic progress made with 'detectors' at various wavelengths, has made this possible. Further, astronomy is not only 'multiwavelength', but 'multimessenger', with cosmic rays, neutrinos and gravitational radiation providing valuable information about astrophysical processes. This lecture is an overview of the unfolding revolution and forms the preamble to this exciting series of lectures.