We have previously shown in our previous article that Big Bang and Albert Einstein’s general theory of relativity points towards the origin of the Universe. However one of the objections to this claim comes from Stephen Hawking’s works on Quantum Cosmology.
Quantum cosmology is the attempt in theoretical physics to develop a quantum theory of the Universe. This approach attempts to answer open questions of classical physical cosmology, particularly those related to the first phases of the universe.
In Quantum Cosmology, you have the light-cone of the expanding universe stretching out; and inside the tiny little fraction of time, corresponding to a point in time when the universe was compressed together and it was so small that it could be describable by quantum mechanics. It is inside that tiny point of time it is possible that our deterministic understanding of physics would break down, thus a classical theory like general relativity could not be applied in that domain.
This is the claim of some quantum cosmologists.
First of all, not everyone accepts that interpretation of quantum mechanics. Peter Hodgson for example disputes idea that determinism breaks down even in that microscopic realm. He takes the uncertainty principle to be a principle of epistemological uncertainty and not a true indeterminacy. But if you do take the more standard, more popular quantum interpretations then you get idea that inside Planck time all that exists is what’s called the universal wave function.
According to Stephen Hawking a universal wave function could be used to define the state of the universe. The wave function is represented by Ψ (psi) derived from the SchrÖdinger equation. This wave function is constructed by considering the amplitude and complete history of the states of the system, which one could refer back to at the very beginning.
This wave function was considered for defining the concept of quantum gravity. The mathematical operation that involved this understanding, faced with many hurdles in the view of Stephen Hawkins, namely “singularity”.
One of such singularities exist at the moment of initiation of the universe, i.e the big bang. An initial cosmological singularity forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of space and time, through such an extremity, as we have explained previously.
In other words, the ‘problem’ in the eyes of Stephen Hawking arose in the form of a question as to what existed before big bang. This problem was faced in real time based analysis of the problem. This led him to a hypothetical refinement of the mathematical analysis which lead to transformation of real time into imaginary time. This hypothetical approach helped in getting rid of the aforementioned ‘problem’ of singularity and thus the need of a cause beyond the universe.
However, the drawback of this approach is that this could not be translated in real time and thus is not applicable to the real world.
This means that in the real world the ‘problem’ of singularity still exists pointing towards a beginning of the Universe. Thus our previous conclusion of a cause beyond the universe still holds.