Modern cosmology developed along tandem

Modern cosmology developed along tandem tracks of theory and observation. In 1915, Albert Einstein formulated his theory of general relativity, which provided a unified description of gravity as a geometric property of space and time. At the time, physicists believed in a perfectly static universe that had no beginning or end. Einstein added a cosmological constant to his theory in order to force it to model a static universe containing matter. This so-called Einstein universe is, however, unstable; it will eventually start expanding or contracting. The cosmological solutions of general relativity were found by Alexander Friedmann, whose equations describe the Friedmann-Lemaître-Robertson-Walker universe, which may expand or contract.



alcohol free wine drinks
Vibrators