Science
a person who studies chemistry
chemist
someone who writes
writer
study of time
horology
a person who studies physics
someone who draws
artist
study of existence
ontology
a person who studies biology
biologist
someone who reports
journalist
study of knowledge
epistemology
a person who studies astronomy
astronomer
someone who studies words
study of right and wrong
ethics
a person who studies weather
meteorologist
someone who studies languages
linguist
study of the brain
psychology