Stephen Hawking is a scientist.
Cosmology ( from the Greek κόσμος , kosmos `` world '' and - λογία , - logia `` study of '' ) is the study of the origin , evolution , and eventual fate of the universe . Physical cosmology is the scholarly and scientific study of the origin , large-scale structures and dynamics , and ultimate fate of the universe , as well as the scientific laws that govern these realities . Stephen William Hawking , ( born 8 January 1942 ) is an English theoretical physicist , cosmologist , author and Director of Research at the Centre for Theoretical Cosmology within the University of Cambridge . Hawking was the first to set out a theory of cosmology explained by a union of the general theory of relativity and quantum mechanics .