To explain the cosmos without invoking cosmic inflation, physicist Neil Turok has proposed the existence of a mirror-image universe going backwards in time from the big bang. He tells us why the idea is so compelling
Physics
25 January 2023
Nibali Nezzar
COSMOLOGICAL inflation is the idea that, in its first moments, the universe underwent a sudden, extreme expansion. This is widely accepted because it explains why space-time is almost perfectly flat and why matter in the cosmos appears so smoothly distributed on the largest scales. Or does it? The trouble is that there are many versions of inflation, most of which wouldn’t lead to the universe we observe – and the need for such “fine-tuning” of the theory to match observations makes some physicists nervous.
Among them is Neil Turok, former director of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, and now at the University of Edinburgh, UK. Turok, alongside Latham Boyle at the Perimeter Institute, has proposed an alternative to inflation that can explain the evolution of the early universe without fine-tuning. In 2018, by taking seriously one of the deepest symmetries of nature, they arrived at a mind-boggling hypothesis: a mirror universe stretching backwards in time from the big bang.
An unobservable anti-cosmos is hard to swallow. It didn’t help that the observations of strange particles by the ANITA telescope in Antarctica, initially invoked as potential evidence for the idea, turned out to be a false alarm. But Turok and Boyle have developed their thinking. Now, following a flurry of papers, they argue that the mirror universe explains all the stuff that inflation can, but also several other mysteries, including that of dark matter and dark energy. They have even made testable predictions in an attempt to win over sceptics.
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Neil Turok: Inflation was based …
Source link The renowned physicist, Neil Turok, has recently proposed a concept of a mirror-image universe in a recent interview. In this interview, he discussed the idea of two universes connected by a membrane and his motivations for introducing this concept.
Turok’s motivation for exploring this idea is based on the notion that matter and energy are conserved. He suggests that if two universes are linked and an equal amount of matter and energy is moved from one to the other, there would be perfect balance in the conservation of matter and energy. To further support his idea, he cites research that suggests that our universe might have begun as a vacuum.
Turok’s concept proposes two copies of the universe that are connected by a membrane, the mirror-image universes. This membrane exerts a powerful repulsive force on matter of the opposite type and would prevent the fusion of the two universes. Turok believes that this could be the result of a phenomenon known as antisymmetry, where properties remain the same when switches between the two universes.
During the interview, Turok proposed several theories to provide further detail on his concept. He suggested that each universe began as a separate point-like single source, connected by the membrane. He also hypothesizes that matter and energy could be transported between points in the mirror-image universes in order to maintain balance of these two forces.
This concept of a mirror-image universe is certainly an intriguing idea, and it will be interesting to see if further research can be conducted to validate Turok’s suggestions. The implications of Turok’s ideas could reach far beyond the universe itself, and could have far-reaching implications on numerous scientific fields. As we wait to find out if Turok’s ideas are validated, one thing is certain: the world of physics is certainly an exciting place these days.
