Narlikar, J. V.2012-03-232012-03-232000-05-10http://hdl.handle.net/11007/1562This is a broad-brush review of the development of cosmology during the twentieth century. The ‘past’ deals with the first nine decades of the century while the ‘present’ deals with the last decade. Although technological achievements have helped the astronomer in better viewing the universe, a ‘final’ under-standing still eludes the search for the correct cosmological model. The article ends with a list of un-solved questions which the ‘future’ may eventually answer.enCosmologyExpanse of the universeFriedmann modelCosmic microwave background radiationOptical telescopeModern detectors and instrumentsMulti-object spectroscopyObservational programmeArticle