theories that made Professor Stephen Hawking one of the greatest physicists of our time

Professor Stephen Hawking , the physicist regarded as one of the most intelligent people the world has ever known, has died at the age of 76.
The physicist was also actively involved in the search for alien life beyond our planet, and extremely vocal about his worries around artificial intelligence.

Here’s a look at some of the controversial theories that made Professor Stephen Hawking one of the greatest physicists of our time.

1. Black holes
   In the 1960s and 1970s, Hawking worked on several theorems regarding general relativity, and made the prediction that black holes should emit radiation - something now known as Hawking radiation.

2. The theory of everything
   As Hawking’s research into black holes continued, he increasingly indicated that there must be an all-encompassing theory of quantum gravity, which he dubbed the "theory of everything”.

3. The Big Bang theory
   In the 1980s, Hawking called into question the Big Bang theory itself, suggesting that there may have never been a start and would be no end.

1. Views on God
   Hawking was well known for his view that there is no God.

In his 1988 book, ‘A Brief History of Time’, he suggested that the discovery of an overarching theory of everything would allow us to "know the mind of God.”

1. The search for aliens
   Along with Mark Zuckerberg and Yuri Milner, Hawking founded Breakthrough Initiatives - a programme looking find alien life beyond our planet.

1. Warnings about artificial intelligence
   Hawking made several chilling warnings about the imminent rise of artificial intelligence.

During an interview with Wired last year, he said: “I fear that AI may replace humans altogether.

“If people design computer viruses, someone will design AI that improves and replicates itself.