Renowned British physicist Stephen Hawking, whose mental genius and physical disability made him a household name and inspiration across the globe, died at age 76 on Wednesday.

The physicist and cosmologist had defied death for decades after being diagnosed with Lou Gehrig’s disease when he was a 21-year-old student at Cambridge University. Most people die within a few years of the diagnosis of the disease, also called the motor neurone disease.

Hawking in spite of his various physical challenges, wrote as many as seven books on physics and co-authored five others.

In his last days, he communicated only by twitching his right cheek. Since catching pneumonia in 1985, Hawking needed round-the-clock care and relied on a computer and voice synthesizer to speak.