accelerating universe albert einstein arno allan penzias boomerang experiment big bang big bang nucleosynthesis big crunch cosmic gravitational wave background cosmic inflation cosmic microwave background radiation cosmic neutrino background cosmological constant creation myth dark energy dark matter digital object identifier edwin hubble ekpyrotic friedmann equations future of an expanding universe galaxy formation and evolution george gamow george smoot globular cluster gravitational singularity integral lambda-cdm model large-scale structure of the cosmos metric expansion of space million nasa neutrino observational cosmology photon red dwarf redshift robert woodrow wilson scale factor shape of the universe sloan digital sky survey stephen hawking structure formation timeline of cosmology timeline of the big bang turnoff point type ia supernova universe vera rubin white dwarf wilkinson microwave anisotropy probe year