Whether one defines time as a measure of moments, or as an element of spacetime, it's a dimension that's thought to have existed even before the Big Bang created the known Universe some 13.8 billion years ago.
This theory that time preceded existence, implausible as this might seem, has been with us for close to a century. A new study again espouses the supposition time did indeed exist before the Universe itself but in another Universe that gave birth to our own.
This assumption isn't all that radical since Albert Einstein's Theory of General Relativity (published in 1915) demonstrated the Big Bang might not have been the absolute beginning of everything as we know it.
The study by University of Oxford physicists David Sloan, Tim A. Koslowski and Flavio Mercati posit a new model of the Universe. Their study published in Physics Letters B re-interprets how time might have existed before the Big Bang itself by circumventing the limits brought on by the idea of an Initial Singularity, or that infinitesimally small blip gave birth to the Universe.
Some theorists propose there is a "mirror Universe" or a "flipped Universe" on the other side of our own Universe. In this other side, time moves backward. The model proposed by the three scientists, however, champions a new way of looking at the idea of a flipped Universe.
It starts with a new interpretation of the ideal of the initial singularity, which is the hypothesized singularity of infinite density before quantum fluctuations caused the Big Bang and the subsequent inflation that created our Universe.
The conventional wisdom is that physics, as we know, is becoming irrelevant or breaks down inside the initial singularity. This break down arises from a contradiction in properties at a particular point in time as defined by general relativity.
Sloan, Koslowski, and Mercati disagree with the assumption of an inevitable break down in physical laws inside the singularity. Instead, they adhere to the assumption physics at the Big Bang remained intact but the stage it acted upon "reorientated."
And instead of a singularity, the team said there is this thing called a "Janus Point." In this Janus Point, the relative positions and scales of the stuff that comprises the Universe flatten into a two-dimensional (2D) pancake as we rewind time.
Passing through the Janus Point, that pancake turns 3D again, only back-to-front, so that time now moves forward. Sloan, Koslowski, and Mercati believe their Janus Point could have profound implications on symmetry in particle physics, and might even produce a Universe based primarily on antimatter.
While the idea of a flipped Universe is nothing new, the model proposed by Sloan, Koslowski, and Mercati of working around the singularity problem is novel.
"All the terms that are problematic turn out to be irrelevant when working out the behavior of quantities that determine how the Universe appears from the inside," said Sloan.
"We introduce no new principles, and make no modifications to Einstein's Theory of General Relativity -- only of the interpretation that is put upon objects."
