Two theories revolutionized the 20th century view of space and time - Einstein's general theory of relativity and quantum physics. This work presents developments in cosmology, theoretical physics and mathematics, and covers the future of spacetime physics.

Astrophysical Neutrinos: 20th Century and Beyond (J N Bahcall, Institute for Advanced Study, Princeton); The Case for Discrete Energy Levels of a Black Hole (J D Bekenstein, The Hebrew University of Jerusalem); The Measure of Cosmological Parameters (W L Freedman, Carnegie Observatories, Pasadena); Progress in Weakly Coupled String Phenomenology (M K Gaillard, University of California, Berkeley); Spacetime Quantum Mechanics (J B Hartle, University of California, Santa Barbara); Inflation and String Cosmology (A Linde, Stanford University); Spacetime and Vacuum as Seen from Moscow (L B Okun, ITEP, Moscow); The Dark Side of the Universe (J Silk, Oxford University); Geometry and Spacetime (S-T Yau, Harvard University); and other papers.