'Cosmic inflation:' did the early cosmos balloon in size? A mirror universe going backwards in time may be a simpler explanation

Our most powerful telescopes have revealed that the cosmos is surprisingly simple on the largest visible scales.

But our most powerful “microscope”, the Large Hadron Collider, has found no deviations from known physics on the tiniest scales.

Inflation is popular because it potentially explains why the energy density in the early universe varied slightly.

It is high time, I believe, to acknowledge and learn from these failures, and to start looking seriously for better alternatives.

Recently, my colleague Latham Boyle and I have tried to build simpler and more testable theories that do away with inflation and string theory.

We have attempted to tackle some of the most profound cosmic puzzles with a bare minimum of theoretical assumptions.

Neil Turok is the inaugural Higgs Chair of Theoretical Physics at the University of Edinburgh .

His day job is developing and testing fundamental physics theories of the universe.

He says a symmetrical mirror universe could provide the simplest explanation of the cosmic dark matter and the primordial density variations.

But more work is needed to show that our new theory is mathematically sound and physically realistic.