Renown theoretical physicist Stephen William Hawking (1942-2018) was born in Oxford, England and studied relativity at Cambridge.

His best-selling book A Brief History of Time (1988) celebrated the study of black holes, which result from the death of stars, and the universe's big bang theory of origin.

Many consider him to be the most brilliant scientist since Albert Einstein. In fact, his classmates nicknamed him "Einstein."

"It matters if you just don't give up," he said.

Hawking's accomplishments are especially remarkable because in 1963 he was diagnosed with Lou Gehrig's amyotrophic lateral selerosis, ALS, a disabling and incurable neuromuscular disease.

Drawing on courage, stubbornness, and a wry sense of humor, he continued working, in a wheel chair and with a computer enhanced voice box.

''My wife says I'm a born optimist,'' he said in 1998, ''so maybe you shouldn't believe me.

On March 4, 2002, the scientist fulfilled a lifelong dream of riding in a hot-air balloon, floating across the Cambridgeshire countryside with his wife, Elaine.

"If you are disabled physically, you cannot afford to be disabled psychologically," he explained. "When you are faced with the possibility of an early death, it makes you realize that life is worth living and there are lots of things you want to do."

Hawking brought together relativity and quantum mechanics to create a new way to look at space, time, and the universe. "My goal is simple," Hawking said. "It is a complete understanding of the universe."

Don't let expectations slow your down.