Defying the Odds, Stephen Hawking Will Turn 70 This Weekend

Renowned physicist and cosmologist Stephen Hawking will turn 70 years old this Sunday - 49 years after being diagnoses with Lou Gehrig's disease. Most people with the disease die within a few years of diagnosis and only 10 percent of patients survive longer than a decade.

Hawking, the author of A Brief History of Time, is almost entirely paralyzed and has been wheelchair-bound since 1970. He relies on a computer and voice synthesizer to speak.

Lou Gehrig's disease, also known as amyotrophic lateral sclerosis, or ALS, attacks motor neurons, which control the muscles. Patients commonly suffer muscle weakness and wasting, become paralyzed and have problems talking, swallowing and breathing.

To learn more about Hawking's life and work, click here.