The description of the emergence of four fundamental forces...

The description of the emergence of four fundamental forces and twelve discrete subatomic particles is almost a common-place in modern physics. There is little doubt among scientists that we live in the aftermath of a giant explosion which occurred around 15 billion years ago -- give or take a few billion.

John Gribbin, an astrophysicist at Cambridge University, summarizes the importance of Big Bang cosmology in this way: “ the discovery of the century, in cosmology at least, was without doubt the dramatic discovery made by Hubble, and confirmed by Einstein’s equations, that the Universe is not eternal, static, and unchanging.”2 In 1988, Hawking observed that as a result of Big Bang cosmology the question of the beginning of the universe entered “the realm of science.”3 More recently he has argued that we can have no scientific theory of nature unless the theory accounts for the beginning of the universe.

The only way to have a scientific theory is if the laws of physics hold everywhere, including at the beginning of the universe. One can regard this as a triumph of the principles of democracy: why should the beginning of the universe be exempt from the laws that apply to other points?

If all points are equal, one can’t allow some to be more equal than others.4 This confidence that cosmology now can address the beginning of the universe -- a confidence shared by many cosmologists -- has led to all sorts of speculations about the initial state of the universe.

For many scientists, philosophers, and theologians such speculations in cosmology speak directly to long-established beliefs about creation.5 Most physicists refer to the Big Bang as a “singularity,” that is, an ultimate boundary or edge, a “state of infinite density” where spacetime has ceased. Thus it represents an outer limit of what we can know about the universe.

If all physical theories are formulated in the context of space and time, it would not be possible to speculate, at least in the natural sciences, about conditions before or beyond these categories. Nevertheless, during the last twenty years, precisely such speculation has intrigued several cosmologists.6 Some of them now offer theories which propose to account for the Big Bang itself as a fluctuation of a primal vacuum.