By Roger Highfield, Science Editor
Prof Stephen Hawking has come up with a new idea to explain why the Big Bang of creation led to the vast cosmos that we can see today.
In this theory, the early universe can be described by a mathematical object called a wave function and, in a similar way to the light particle, the team proposed two years ago that this means that there was no unique origin to the cosmos: instead the wave function of the universe embraced a multitude of means to develop.
This is very counter intuitive: they argued the universe began in just about every way imaginable (and perhaps even some that are not). Out of this profusion of beginnings, like a blend of a God’s eye view of every conceivable kind of creation, the vast majority of the baby universes withered away to leave the mature cosmos that we can see today.
But, like any new idea, there were problems. The professors found that they could not explain the rapid expansion - inflation - of the universe, evidence of which is left behind all around us in what is called the cosmic microwave background, in effect the echo of the big bang, a relic of creation that can be measured with experiments on balloons and on space probes.
Now, in a paper in Physical Review Letters with Prof James Hartle of the University of California, Santa Barbara, they realised that their earlier estimates of inflation were wrong because they had not fully thought through the connection between, on the one hand, their theoretical predictions and, on the other, our observations of the echo.
At first, they found that the most probable history of the cosmos had only undergone "a little bit of inflation at the beginning, contradicting the observations," said Prof Hertog. Now, after a correction to take account of how the data we have on inflation is based on only a view of a limited volume of the universe, they find that the wave function does indeed predict a long period of inflation.