The Past Universe

1

As we roll back time, the universe must contract towards the generalised definition of a cosmic singularity beyond which science cannot yet follow. As such, we might define this point as the quantum beginnings of our universe, which is positioned 10-43 seconds along the timeline of expansion of 'our' universe.

So far, we have outlined a finite universe, based on the interpreted redshift observations, which led to the idea of an expanding universe. This expansion originally defined by Friedmann's equations also led to the estimated age of the universe being some 13.7 billion years - see 'Modelling Friedmann'. However, our understanding of the quantum universe is limited, as there is no proven interpretation of what this theory is really telling us about the true nature of quantum reality in terms of either time or space. However, theory does suggest that we are talking about a time period within the first 10-35 second of the existence of 'our' universe in which the laws of space and time, as we currently understand them, may not yet have been created. Therefore, to some extent, we are in the realm of quantum speculation, rather than any empirical reality. Generally, for the purposes of this discussion, the terminology of particle physics will be kept to a minimum, although there are some key terms that are required by cosmology in order to describe the processes taking place in the early universe:

  • Hadrons, e.g. protons/neutrons, are quarks bound by strong nuclear forces
  • Fermions have ½, odd spin, e.g. protons, neutrons, electrons
  • Fermions obey the Pauli exclusion principle
  • Baryons are hadrons with the property of fermions
  • Leptons are light fermions, e.g. electrons
  • Bosons have integral spin, e.g. photons
  • Boson do not obey the Pauli exclusion principle

For the sake of simplicity, baryons and hadrons are essentially the same as protons and neutrons, which in turn are comprised of quarks. In the early universe, the energy-temperature was so high; even quarks held together by the strong nuclear force could not initially bind together to form protons or neutrons, which are subsequently required to form atomic nuclei.

Note: As science continues in its attempts to rollback time, it is left trying to describe the nature of space-time in which no structural matter existed and even the 4 fundamental forces of nature may not have existed separately. There is also a suggestion that the spatial structure of spacetime might not have been limited to just 3 dimensions, but extended to 10 dimensions plus time. As such, it would be a universe that defies our human senses and will remain a challenge for mathematics to even describe for many years to come, despite the initial optimism of 20th century science - see String Theory for more details on this idea.