Light in Einstein's universe

The great astronomical discoveries of recent years are discussed and our new understanding of the observable universe is expressed as a cosmological model which considers the universe as a unique mass-energy system. This model has many interesting consequences and offers a physical basis of gravitation, inertia and the source of relativistic effects. This original approach has considerable relevance to our notions of space and time, and to the nature of physical systems in general. (author). refs.; figs.; tabs