COSMOLOGICAL inflation is the idea that the universe suddenly expanded to an extreme in the first moment. This is widely accepted because it explains why spacetime is almost perfectly flat and why matter in the universe appears to be smoothly distributed at the largest scales. Or is it? The problem is that there are many versions of inflation, most of which do not lead to the universe we observe. Also, the need to “tweak” the theory to match observations has made some physicists nervous.
Among them are Neil Turok, former director of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, and is now at the University of Edinburgh, UK. Turok, together with Latham Boyle of the Perimeter Institute, proposed an alternative to inflation that could explain the evolution of the early universe without fine-tuning. In 2018, they took him one of nature’s deepest symmetries seriously and came up with a daunting hypothesis. It is that the universe of mirrors stretches back in time from the Big Bang.
The unobservable anti-universe is hard to swallow. Observations of strange particles with his ANITA telescope in Antarctica were initially cited as potential evidence for the idea, but what turned out to be a false alarm did not help. But Turok and Boyle have developed their own ideas. Now, following a flurry of papers, they claim that the mirror universe not only explains everything inflation can do, but also several other mysteries, including those of dark matter and dark energy. They even made testable predictions to persuade the skeptics.
Thomas Lewton: Can you first explain how the idea of inflation became dogma?
Neil Turok: The rationale for inflation is…