It may not quite compare with the doughnut-shaped universe theory which Professor Stephen Hawking threatened to steal from Homer in a famous episode of The Simpsons.
But the renowned cosmologist’s final published theory, submitted before his death on March 14, provides just as much food for thought.
Working with Belgian colleague Professor Thomas Hertog, Prof Hawking extended the weird notion of a holographic reality to explain how the universe came into being from the moment of the Big Bang.
The new paper, published in the Journal Of High Energy Physics, challenges previous theories of cosmic “inflation” and the “multiverse”.
Cosmologists believe that for a tiny fraction of a second after the Big Bang the universe expanded incredibly rapidly before settling into its present state, filled with stars and galaxies.
Some have proposed that on a much grander global scale inflation goes on for ever, giving rise to a “multiverse” – a mosaic of different universes with their own laws of physics. We inhabit just one of these “pocket” universes in a region where locally inflation has ended.
Prof Hawking was always troubled by this idea, which at a fundamental level cannot be reconciled with Einstein’s theory of General Relativity. In an interview last year he said: “I have never been a fan of the multiverse.”
The new theory embraces the strange concept that the universe is like a vast and complex hologram. In other words, 3D reality is an illusion.
The apparently “solid” world around us – and the dimension of time – is projected from information stored on a flat 2D surface.
Hawking and Hertog’s variation of the holography theory overcomes the problem of combining eternal inflation with General Relativity.
Prof Hertog, from the Katholieke Universiteit Leuven (KT Leuven), said the concept of a holographic universe emerged from string theory, the idea that the smallest building blocks of the universe consist of tiny vibrating strings.
He said: “It’s a very precise mathematical notion of holography that has come out of string theory in the last few years which is not fully understood but is mind-boggling and changes the scene completely.”
Applied to inflation, the newly published theory suggests that time and “the beginning” of the universe arose holographically from an unknowable state outside the Big Bang.
“The key point is that we’re not projecting out a spatial dimension. We are projecting out the dimension of time from ‘before’ the Big Bang,” said Prof Hertog.
“It’s a theory that envisages a beginning to the universe where time is not present but our notion of time crystallises, and it’s saying that time is fundamentally coming out of some other state for which we have no words. Some very abstract timeless state – that’s the best we can do.”
The theory does not completely do away with the multiverse but no longer envisages an infinite “fractal” structure.
Prof Hawking said before his death: “We are not down to a single, unique universe, but our findings imply a significant reduction of the multiverse, to a much smaller range of possible universes.”
Prof Hertog believes gravitational waves – ripples in space time first detected in 2015 – could provide a “smoking gun” to test the model.