physicist vs James Alfred Van Allen

physicist and James Alfred Van Allen both are nouns.

Word	Noun	Adjective	Verb	Adverb
physicist	Yes	No	No	No
James Alfred Van Allen	Yes	No	No	No

physicist (noun)	James Alfred Van Allen (noun)
a scientist trained in physics	United States physicist who discovered two belts of charged particles from the solar wind trapped by the Earth's magnetic field (born in 1914)