His principal areas of research are cosmology and quantum gravity. His major contributions to the field of research included his papers on the relationship between black holes and thermodynamics. His research indicated that black holes do not exist forever, but rather that virtual particle pairs created near their event horizons cause them to "evaporate" over time in a process known as Hawking radiation. He is also known for his chronology protection conjecture which hypothesizes the theoretical impossibility of closed timelike curves.
In spite of being severely disabled by Motor Neurone Disease, he is highly active in physics, writing, and public life. He has used an electronic voice synesizer to communicate since he had a tracheotomy in 1985 following a severe bout of bronchitis. Due to his disease, he is now almost completely unable to move. The computer system attached to his wheelchair is operated by Hawking manually through a device called "Clicker", which lets him select words and other options on his computer's screen, but can be controlled by head or eye movement as well. He was first diagnosed at the age of 21, shortly before his first marriage. The doctors didn't give him more than perhaps two to three years by that time.
His two books A Brief History of Time and The Universe in a Nutshell have remained highly popular all over the world and are now classic best-sellers. Anyone interested in the universe, cosmos and how it all began can read them: no previous knowledge in this field is required to enjoy these books.
In popular culture, he has become a widely admired figure as a genius who has had a successful life despite his severe disability. He had a guest appearance on an episode of the television series , playing poker with Data, Albert Einstein, and Isaac Newton in the episode "Descent, Part I." The animated television series The Simpsons and Futurama have occasionally featured him in episodes, and a character playing Hawking has appeared in the television series Dilbert. He also lent his voice to the Pink Floyd song Keep Talking off The Division Bell. A parody website even has a Hawking-like voice synthesizer rapping about physics [1]
From his first marriage with Jane Wilde Hawking he has three children, named Tim, Lucy and Robert. When Jane was asked why she decided to marry a man with a 3-year life expectancy, she responded: "These were the days of atomic gloom and doom, so we all had rather a short life expectancy". He married his second wife Elaine Mason in 1995.
Hawking is famous for his oft-made statement, "When I hear of Schrödinger's cat, I reach for my gun." This was a deliberately ironic paraphrase of Hermann Göring's anti-intellectual quote, "When I hear the word 'culture', I reach for my Browning", which itself was from a play by German playwright and Nazi Poet Laureate, Hanns Johst.
