There is no God. No one directs the universe,” says celebrated physicist Stephen Hawking in his final book “Brief Answers to the Big Questions.” His book also covers important existential questions such as the creation of the universe, alien intelligence, space colonization, and artificial intelligence.

He was diagnosed with Motor Neuron Disease, also known as ALS or Lou Gehrig’s disease) at the age of 20,  and was given two years to live. Though he was the longest living MND survivor, he died in March, at the age of 76. In the film “The Theory of Everything” his battle with the disease has been featured for which actor Eddie Redmayne, who played Hawking, received 2015’s Best Actor Oscar.

Hawking is also much renowned for his work in cosmology and theoretical physics, notably for Hawking radiation and his work on black holes, was the director of research at the Centre for Theoretical Cosmology and Lucasian Professor of Mathematics at the University of Cambridge.

In his book, he wrote, “For centuries, it was believed that disabled people like me were living under a curse that was inflicted by God. Well, I suppose it’s possible that I’ve upset someone up there, but I prefer to think that everything can be explained another way, by the laws of nature,” he wrote in the chapter titled “Is There a God?”

Google has shared an animated video Doodle in order to celebrate Hawking’s 80th birthday. The video in the first-person narrative of Stephen Hawkins takes us through his life journey using a computer-generated voice. The video explains his contribution to the world and science along with his deteriorating health conditions.