Book Reviewed: Before Time Began: The Big Bang and the Emerging Universe, by Helmut Satz

Cosmos and emerging realities

In this book, the author discusses as how different horizons, on Earth and in the heavens define our perception of physical reality. This book is not meant to give a systematic presentation of recent developments in cosmology but discusses with an emphasis on emerging realities such as gravity in terms of laws thermodynamics.

Emergent phenomenon contrasts with reductionism. A new outcome such as gravity from space and time is different from spacetime. Two basic approaches have dominated physics and cosmology; the reduction approach to divide and subdivide matter to its most fundamental particles governed by its quantum nature, and building and extensions of quantum particles into stars, galaxies, universe and multiverse according relativistic physics. Thermodynamics is a framework that describes how very large numbers of individual constituent particles behave. Since then, physicists have tried to figure out whether this similarity of relativity and thermodynamics is a formal coincidence or hints of a deeper truth. Because space-time is made of small elements whose collective motion gives rise to the force we call gravity. In this case, gravity would not be a truly fundamental phenomenon, but an emergent one like temperature, pressure, and viscosity. The microscopic constituents of space-time push inwards on matter and this pulls normal matter in by its gravitational attraction. In the thermodynamic formulation of gravity, the entropy is the number of possible microscopic configurations. Entropic gravity, also known as emergent gravity is an entropic force, a force with macro-scale homogeneity but which is subject to quantum-level disorder, and not as a fundamental interaction. This theory is based on string theory, black hole physics, and quantum information theory describes gravity springs from the quantum entanglement of small bits of spacetime information.

Entropy is really about the level of information we need to describe a system. An ordered system (say, marbles evenly spaced in a grid) is easy to describe because the objects have simple relations to each other. On the other hand, a disordered system (marbles randomly scattered) take more information to describe, because there isn’t a simple pattern to them. So, when the second law says that entropy can never decrease, it is to say that the physical information of a system cannot decrease. In other words, information cannot be destroyed.

Considering infinite space, there is a growing acceptance among physicists that we live in multiverse and our existence is a part of space with eternal inflation which is creating billions of parallel universes. According to Stephen Hawking’s last paper, the evidence of the multiverse exists in cosmic microwave background (CMB) radiation.

The last chapter, entitled “The Last Veil,” the author presents an interesting discussion of space and time and its cosmic connections. The introductory part of the book briefly discusses the cosmos according to the two major schools of Hindu philosophy, and the Greek natural philosophy. Highly readable and very energizing book.