This volume, devoted to the problems of relativity, gravitation and related issues in physics, presents papers delivered and/or discussed during the conference "Redshifts and Gravitation in a Relativistic Universe" held in Cesena on September 17-20th 1999. In a way, this conference represents a response to Zwicky"s method, outlined above. Its main aim was to serve as a forum for ideas and theories that go against the mainstream of science. Some of the theories are already cast in their final form; some are just rough ideas still undergoing development.