Stephen Hawking has revealed from beyond the grave his final scientific theory – that the universe is a hologram.
The cosmologist, who died on March 14, has challenged previous theories of cosmic “inflation” and the “multiverse” in a new paper published in the Journal Of High Energy Physics.
Scientists generally 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 – the inflation theory.
But some have proposed that, on a grander global scale, inflation goes on for ever, giving rise to a “multiverse” – a number of different universes with their own laws of physics.
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.”
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 theory embraces the strange concept that the universe is like a vast and complex hologram. In other words, 3D reality is an illusion, and that 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: “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.
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.”