Alternative to Big Bang Proposed

Cosmologist Cristiano Germani, of the International School of Advanced Studies in Trieste, has proposed an alternative to the widely accepted theory that the universe was created by a big bang, followed by rapid inflation.

Speaking at the University of Sussex, Germani revealed his alternative, which is based on a model of string theory in which the three visible dimensions of space are confined to the surface of a membrane, or brane, that floats in a 10-dimensional space.  The extra dimensions of space are enclosed in Calabi-Yau space, a shape that is both complex and unstable. 

Calabi-Yau space is constantly vibrating, and each wobble of the surface should create unwanted particles and extra forces in the universe. However, these have never been observed. When string theorists try to stabilise Calabi-Yau space they always warp it, creating strange spikes and throats. 

Germani believes this warping explains how the universe evolved.  Germani and his team looked at what would happen if a brane containing the universe fell down one of these throats.  At first it seemed that the universe would just fall into the throat, getting squeezed until it was crushed at the tip of the throat. This would correspond to the universe collapsing on itself. 

However, Germani then thought of what would happen if the universe were spinning. He found that the spinning motion would cause the universe to avoid the tip of the throat, whirl round it and shoot back out like a boomerang or a stone from a slingshot.  Germani believed that the universe shooting back out could correspond to the universe expanding. 

While other cosmologists have suggested that the universe went through cycles of big bangs and big crunches, similar to what Germani’s theory suggests, Germani’s alternative is the only one that can solve the “horizon problem” without depending on rapid expansion of the universe immediately after its creation. The horizon problem states that no matter where you look in the universe, the background temperature is always the same, but not enough time has elapsed since the big bang for radiation to travel across the universe.  By postulating that the universe expanded rapidly after the big bang, the problem is solved because regions that are on opposite sides of the universe may once have been close together. 

With Germani’s theory, however, there is no big bang, so there is no horizon problem. There is no beginning of time, so it is possible for regions on opposite sides of the sky to have been in contact in the past.