As an Oxford student, Stephen Hawking never expected that people across the world would know his name, or that his hobby of stargazing would lead him to be one of the world's greatest scientists. Stephen Hawking made cosmology, or the study of the universe, accessible to everyone. 

He was diagnosed with amyotrophic lateral sclerosis at the age of twenty-one, but didn't let that stop him from receiving a graduate degree from Cambridge and going on to be an expert in the scientific origin of the universe and black holes. 

Hawking is best known for writing A Brief History of Time, which explained cosmology in non-scientific terms so that non-scientists could understand it.