Stephen Hawking is a world renown cosmologist. He was born January 8, 1942 in Oxford, United Kingdom. At the age of 21 while studying at the University of Cambridge he was diagnosed with a disease called Amyotrophic Lateral Sclerosis (motor neurone disease), which over time crippled him. Motor neurone disease is a small group of neurological diseases that over time selectively affect your motor neurons. Motor neurons are what allow you to speak, walk, talk, or make any general movement and when they are damaged they leave you immobile. Stephen was a very smart man he developed the theory of black holes and wrote many books about his life's accomplishments.
Stephen Hawking's theory of the black hole has helped us understand the universe as it exists today.