What caused or initiated the Big Bang if there was nothing before it? Trevor Pitts · July 9Oxford Philosophical Society Member since 1989
The latest idea is that the Big Bang was both at the center of time and the beginning of time. That is, that there are two universes with identical physics, but that in each the direction of time is reversed relative to the other. According to Feynman, all particles have the potential to travel backward in time, whereupon they are equivalent to antimatter. To us, the universe at the other side of the Big bang would appear to be full of antimatter, to them, so would we. In reality both universes are expanding outward in spacetime at the same rate. Both would perceive events as we would, but experience divergent histories due to Quantum indeterminacy leveraged by Chaos and Self-limiting Criticality (avalanche, earthquake etc physics). This concept has great merit because the universe was built upon Symmetry, but unidirectional time, and the dominance of matter versus antimatter in our universe, when both are created equally from energy, clearly violate that symmetry. More particularly, without this hypothesis, a very important symmetry, CPT Invariance, Charge, Parity, Time, Invariance is violated. Basically symmetry requires that if time is reversed, charge (+ or – on battery terminals, -ve electrons versus +ive , antimatter positrons) is reversed and parity reversed. Parity can be understood in that physics is the same in a mirror reflection of a coordinate system.
All equations describing physical interactions work forward or backward in time- time symmetry. This hypothesis can explain the extreme imbalance of matter versus antimatter in our universe by having an equal, opposite, imbalance in the mirror universe, when the big bang’s huge burst of energy must have produced equal amounts of matter and antimatter, almost all of which annihilated each other as the mirror universes expanded and cooled. The tiny amount remaining built the stars, planets etc. here, and their mirror equivalents on the other side of the Big Bang. The two universe are about 26 billion years apart in time- twice the age of either universe.
I apologize for the level of abstraction here, but CPT invariance is fundamental, and without this mirror universe on the other side of the Big Bang, this universe violates it, so our physics must be wrong, or more accurately, incomplete, without such a hypothesis. I wrote a paper on this subject twenty years ago: arXiv:physics/9812021v2
. It was not taken seriously. More recently, Neil Turok’s group at the highly prestigious Perimeter Institute published a series of papers on the subject, giving the hypothesis firmer mathematical support from a loop quantum gravity basis:
They were taken seriously. Turok’s group were able to make a prediction, based on this hypothesis of the mirror universe, about the mass of a type of heavy neutrino that is a plausible candidate for explaining dark matter. This was given support by the detection of neutrinos coming upward out of the Earth in an experimental apparatus in Antarctica. Their masses were a close match for the Turok group predictions. In physics, that is a huge deal- it massively supports the hypothesis.
I should point out that this is very cutting edge physics. It potentially solves multiple huge problems that have plagued physics for ages, if it survives further study. If it does, it is Nobel Prize material, plus, when you think about it, the largest discovery in history- an entirely new universe!
In my mind this hypothesis, time-symmetry across the Origin, answers the question of what was before the Big Bang. There was no “before”. The quantum fluctuation that was of sufficient magnitude to collapse itself into realty (per Penrose’s gravitational collapse of the wave function theory) created spacetime, which exploded outward from the origin in both + and – time. Now there is a whole universe of history “before” the Big Bang, but the creatures living there think we are the ones “before” it. Time is the result of the quantum process of creating events as space and time expand outward together. We think of time as eternal, not so. It was created together with space. Neither can exist without the other, according to Einstein. To ask about time outside spacetime is meaningless. We live in a magnificently complex vacuum. It arose, in my view, because the gigantic sum of all potential histories of quantum events in a universe with exactly the physics that allowed the existence and flourishing of technologically advanced intelligent creatures, overwhelmed the zero history alternative of non-existence. In quantum logic, existence was overwhelmingly more probable than non-existence, if the “right”, suitably fine-tuned quantum fluctuation occurred, perhaps after some unimaginable amount of failed fluctuations. Survival and expansion of the “fittest” universe for non-simple histories?