Oceans were long thought to exist in all corners of the Solar System, from carbonated seas percolating beneath the clouds of Venus to features on the Moon's surface given names such as "the Bay of Rainbows” and the "Ocean of Storms." With the advent of modern telescopes and spacecraft exploration these ancient concepts of planetary seas have, for the most part, evaporated. But they have been replaced by the reality of something even more exotic. For example, although it is still uncertain whether Mars ever had actual oceans, it now seems that a web of waterways did indeed at one time spread across its surface.

This volume is dedicated to the one hundredth anniversary of the publication of Hermann Minkowski's paper "Space and Time" in 1909. His work on the spacetime representation of special relativity had a huge impact on the twentieth century physics to the extent that modern physics would be impossible without the notion of spacetime. While there is consensus on the mathematical significance of spacetime in theoretical physics, for a hundred years there has been no consensus on the nature of spacetime itself.

Observational and experimental data pertaining to gravity and cosmology are changing our view of the Universe. General relativity is a fundamental key for the understanding of these observations and its theory is undergoing a continuing enhancement of its intersection with observational and experimental data. These data include direct observations and experiments carried out in our solar system, among which there are direct gravitational wave astronomy, frame dragging and tests of gravitational theories from solar system and spacecraft observations.

This book addresses the possible origins, development and fate of intelligent life in the universe. The author presents a wide-ranging analysis of the type of knowldege that can be inferred about extraterrestial intelligent societies from our own biological, cultural and scientific evolution, and from the likely future of mankind. Providing extensive background information from astronomy, geology, chemistry and biology, the book will appeal to both the scientist and the general reader.

In the last 25 years, planetary science experienced a revolution, as vast oceans of liquid water have been discovered within the heart of the icy moons of our Solar System. These subsurface oceans lie hidden under thick layers of ice. We call them ocean worlds.

The stars and constellations are among the few remaining objects that appear to us just as they appeared to our distant ancestors. From anywhere on Earth, a person may view the celestial panorama simply by stepping outside at night and gazing upward.