Sunday, May 1, 2011

Gott-Li Model

Richard Gott has suggested a method for a universe to create itself if it formed a causal loop in spacetime (see here). He suggested that a branch of the universe might circle back around and grow up to become the trunk of the main universe (see diagram below). This is a model where the universe is its own mother:

The details of this technique are explained in detail on page 37 of his paper with Li-Xin LiCan the Universe Create Itself?. Gott considers an advanced civilisation capable of creating baby universes (using the method of Farhi, Guth, and Guven which was discussed earlier):"Now suppose one of these open bubble universes simply turns out to be the original open universe where that advanced civilization made the baby universe in the first place". In that case, the universe would indeed be its own mother.

In the introduction of his paper with Li-Xin Li Can the Universe Create Itself?, Gott constrasts his theory's approach to the first cause with that of the No Boundary proposal:"Often, the beginning of the universe, as in Vilenkin's tunneling model and Hartle and Hawking's No Boundary model, is pictured as being like the South Pole of the Earth and it is usually said that asking what happened before that is like asking what is south of the South Pole. But, suppose the early universe contains a region of closed timelike curves. Then, asking what was the earliest point might be like asking what is the easternmost point on the Earth. You can keep going east around and around the Earth - there is no eastern-most point. In such a model every event in the early universe would have events that preceded it."

From by Andrew Thomas

1 comment:

Ulla said... by Andrew Thomas not found.