Well it may be indirectly accessible to us, depending on which of the current
wild speculations theories turns out to be correct.
For instance there is the prediction made by
Quantum Loop Gravity:
Until very recently, asking what happened at or before the Big Bang was considered by physicists to be a religious question. General relativity theory just doesn’t go there – at T=0, it spews out zeros, infinities, and errors – and so the question didn’t make sense from a scientific view.
But in the past few years, a new theory called Loop Quantum Gravity (LQG) has emerged. The theory suggests the possibility of a “quantum bounce,” where our universe stems from the collapse of a previous universe. Yet what that previous universe looked like was still beyond answering.
Now, physicists Alejandro Corichi from Universidad Nacional Autónoma de México and Parampreet Singh from the Perimeter Institute for Theoretical Physics in Ontario have developed a simplified LQG model that gives an intriguing answer: a pre-Big Bang universe might have looked a lot like ours. Their study will appear in an upcoming issue of Physical Review Letters.
“The significance of this concept is that it answers what happened to the universe before the Big Bang,” Singh told PhysOrg.com. “It has remained a mystery, for models that could resolve the Big Bang singularity, whether it is a quantum foam or a classical space-time on the other side. For instance, if it were a quantum foam, we could not speak about a space-time, a notion of time, etc. Our study shows that the universe on the other side is very classical as ours.”
The finding builds on previous research, with some important differences. Last year, Penn State physicist Martin Bojowald used a simplified version of LQG to show that a universe “on the other side” of the bounce could have existed. However, although that model produced valid math, no observations of our current universe could have lead to any understanding of the state of the pre-bounce universe, as nothing was preserved across the bounce. Bojowald described this as a sort of “cosmic amnesia.”
But Corichi and Singh have modified the simplified LQG theory further by approximating a key equation called the quantum constraint. Using their version, called sLQG, the researchers show that the relative fluctuations of volume and momentum in the pre-bounce universe are conserved across the bounce.
“This means that the twin universe will have the same laws of physics and, in particular, the same notion of time as in ours,” Singh said. “The laws of physics will not change because the evolution is always unitary, which is the nicest way a quantum system can evolve. In our analogy, it will look identical to its twin when seen from afar; one could not distinguish them.”
Or there is the theory about
twin universes existing concurrently:
String theorists Neil Turok of Cambridge University and Paul Steinhardt, Albert Einstein Professor in Science and Director of the Princeton Center for Theoretical Science at Princeton believe that the cosmos we live in was actually created by the cyclical trillion-year collision of two universes (which they define as three-dimensional branes plus time) that were attracted toward each other by the leaking of gravity out of one of the universes.
In their view of the universe the complexities of an inflating universe after a Big Bang are replaced by a universe that was already large. flat, and uniform with dark energy as the effect of the other universe constantly leaking gravity into our own and driving its acceleration. According to this theory, the Big Bang was not the beginning of time but the bridge to a past filled with endlessly repeating cycles of evolution, each accompanied by the creation of new matter and the formation of new galaxies, stars, and planets.
Turok and Steinhardt were inspired by a lecture given by Burt Ovrut who imagined two branes, universes like ours, separated by a tiny gap as tiny as 10-32 meters. There would be no communictaion between the two universes except for our parallel sister universe's gravitational pull, which could cross the tiny gap.
Orvut's theory could explain the effect of dark matter where areas of the universe are heavier than they should be given everything that's present. With their theory, the nagging problems surrounding the Big Bang (beginning from what, and caused how?) are replaced by an eternal cosmic cycle where dark energy is no longer a mysterious unknown quantity, but rather the very extra gravitational force that drives the universe to universe (brane-brane) interaction.