London - The Big Bang and the subsequent expansion of the Universe did not need God to set it off, theoretical physicist Stephen Hawking suggested to an audience in California this week.
A combination of quantum theory and the theory of relativity would a better explain our existence than divine intervention, he told a packed auditorium at the California Institute of Technology.
And he suggested that turning to the dark side could illuminate fundamental questions about how the Universe began.
'The missing link in cosmology is the nature of dark matter and dark energy,' the LA Times reported Hawking as saying.
Easily the world's most famous theoretical physicist - perhaps the only one the most people can name - Hawking more then filled the 1,100-capacity auditorium laid on by Caltech for the event.
Queues to hear the Brief History Of Time author started forming a 8am, 12 hours before his talk was scheduled to begin, the LA Times reported.
By 6pm, those eager to see him in person stood in a line a quarter-of-a-mile long, according to Space.com, and still many were forced to sit in an overflow space.
And when that was filled, a thousand more say on a lawn outside the lecture theatre which had been equipped with a big screen and sound system,.
In a wide-ranging talk, the former Cambridge professor recapped various theories of the beginning of the Universe, caricaturing the religious position with the myth of an African tribe whose god vomited the Sun, Moon and stars.
He also discussed theories which suggest that existence in fact had no beginning, and claimed that Edwin Hubble's observations of an expanding Universe and Einstein's theory of relativity had disproved those.
He also had time for a few jokes, one of which paraphrased Martin Luther's response to a young man who dared to ask what God was doing before he made the world.
'If one believed that the universe had a beginning, the obvious question was what happened before the beginning?' he asked.
'What was God doing before He made the world? Was He preparing Hell for people who asked such questions?'
Attempting what could be seen as a kind of Copernican Revolution in cosmology, Hawking tried to explain his point of view that such questions were nonsensical.
'The problem of what happens at the beginning of time is a bit like the question of what happened at the edge of the world, when people thought the world was flat,' he said.
He suggested that the idea of time running in only one direction 'like a model railway track' was misconceived and that combining of general relativity and quantum theory can allow time to act just like another direction in space.
'This means one can get rid of the problem of time having a beginning, in a similar way in which we got rid of the edge of the world,' he said.
Hawking asked his audience to imagine the beginning of the Universe is like the South Pole, with the role of time being played by degrees of latitude.
Just as asking what is south of the South Pole makes no sense, he argued, to asking what happened before the beginning of the Universe would become a meaningless question.
Moreover, conceiving of the Universe in this way also removes 'age-old objections' to the idea that the Universe had a beginning; that it would be a place where the normal laws of physics could not hold.
Instead, Hawking claimed, the beginning of the Universe could be governed by laws of science, which justifies a picture he and fellow physicist Jim Hartle developed as like the formation of bubbles of steam in boiling water.
This claims that the most probably history of the Universe is like the surface of such bubbles, a few of which grow to such a size that they are safe from collapsing.
'They will correspond to universes that would start off expanding at an ever increasing rate' like the expanding Universe we live in, he said.
Quantum theory could best understand how the state of the Universe at the initial point of its formation gave rise to the Universe we live in today 13.5 billion years after the Big Bang, Hawking claimed.
He said: 'General relativity on its own cannot answer the central question in cosmology: Why is the universe the way it is?
'However, if general relativity is combined with quantum theory, it may be possible to predict how the universe would start.'
Small fluctuations in the initial state of the Universe would lead to the formation of 'galaxies, stars, and all the other structure in the universe,' he said.
His theory could be tested when science develops the ability to detect gravitational waves by accurately measuring the distance between spacecraft.
These waves, he said, originated in the earliest times of the universe and have not been altered by their interactions by 'intervening material'.
Hawking, now 71, has been battling degenerative motor-neurone disease related to amyotrophic lateral sclerosis, or Lou Gehrig's disease, for more than 50 years.
His works of popular science have acheived great success, despite the arcane nature of the cosmology he investigates. A Brief History of Time stayed on the Sunday Times best-seller list for a record breaking 237 weeks.
He has been spending a month at Caltech, as he does every year, always drawing huge crowds to hear him speak. - Daily Mail