stephen hawking 76th birthday
Stephen Hawking turned 76 on Jan. 8, 2018. Paul. E. Alers/NASA

Stephen Hawking, the world-renowned physicist and author of "A Brief History of Time," celebrates his 76th birthday Monday.

Nearly 55 years, Hawking was diagnosed with Amyotrophic Lateral Sclerosis, also known as ALS or Lou Gehrig’s disease. Though the disease has left him paralyzed, Hawking has defied the ALS odds.

Most people are diagnosed with the disease between the ages of 55 and 75 and live for two to five years following their diagnosis, according to the Centers for Disease Control. The disease affects the nerve cells that help muscles make certain movements and it eventually leads to the muscles weakening and then paralysis.

Throughout his long life, he’s had the chance to research and study the laws of the universe and make groundbreaking studies about parts of the cosmos like black holes. Since Hawking became one of the most recognized names in the world, he’s bestowed his knowledge and predictions for the future on the general public.

Hawking Quotes

"Although the chance of a disaster to planet Earth in a given year may be quite low, it adds up over time, and becomes a near certainty in the next thousand or ten thousand years," Hawking told BBC last year.

"In short, the rise of powerful AI will be either the best or the worst thing ever to happen to humanity," he said according to Cambridge News.

"Human colonization on other planets is no longer science fiction. It can be science fact," he said at Starmus last year, "If humanity is to continue for another million years, our future lies in boldly going where no one else has gone before."

"We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special," he said.

"I think it would be a great mistake. However bad life may seem, there is always something you can do, and succeed at. While there's life, there is hope," he said in 2006.

"I am discounting reports of UFOs. Why would they appear only to cranks and weirdos?" he said during a TED talk.

"So, if you feel you are in a black hole, don't give up. There's a way out," he said in a speech at the University of Southern California.