SOME OF THE MOST exciting recent developments in physics have been in the realms of the very small and the very large. Chief among the latter was the discovery of “quasars,” which has quadrupled our depth penetration of the universe (if quasars are where most astronomers think they are), and which has also stimulated the possibly irrelevant but intrinsically fruitful investigations into gravitational collapse. Then came the discovery of the 3°K background radiation, which seems to have taken us back a long way in time to an apparent “big-bang” origin of the universe. Both bode ill for the steady-state theory to which many of us had been attracted. Most recently, Robert H. Dicke's speculations and observations on the oblate sun have battered at the edifice of general relativity, and thus at the very foundations of modern cosmology. Even advances in the realm of the very small affect our knowledge of the very large; for, after all, most of the phenomena we see in the sky are manifestations of either gravitational or nuclear activity.