Before looking at further questions concerning the Big Bang model, let’s consider the possible implications of the singularity problem (see previous post) for religion, as this topic often arises in the media.
Our best description of gravity (the dominant force in the universe at large) is Einstein’s general theory of relativity. Applied to the cosmos, general relativity has made some spectacular predictions that have since been verified by experiment (the expanding universe in particular). However, it is true that the theory breaks down as we rewind the clock of the expanding universe all the way back to time zero (the equations blow up to infinity).
Some religiously-minded scientists consider this significant, suggesting that we may be coming to a limit to what the human mind may comprehend about the work of a creator and this is also the view of many theologians. I heard several interesting talks on this topic at Cambridge last year, see the July posts on Cosmology Day at the Faraday Institute here.
Implications for a creator?
However, it’s important to emphasize that most cosmologists would say that the uncertainty really arises from quantum physics. We already know that general relativity is incomplete because it doesn’t incorporate quantum theory (the theory that describes the world of the very small with extreme accuracy). Since the space and time of the infant universe will be of quantum dimensions, we will not be able to describe it until we have a successful quantum theory of gravity. In other words, our current lack of a clear picture of the birth of the universe simply arises from a well-known limitation of the theory of relativity. In time, theoreticians will hopefully find a quantum version of relativity and we will have a clearer picture – so no there are no real implications for religion, one way or the other. I made this point in a public talk on the Big Bang last year (see post on this here), and you can find my description of the lecture in the July issue of Physics World 2008.
Interestingly, one thing we do know from quantum theory is that, even with a successful theory of quantum gravity, some uncertainty will always apply to the first instant of the universe. This is because one of the central tenets of quantum physics is that an inherent fuzziness pertains to the properties of phenomena on the smallest scales (not just a fuzziness in measurement, as many philosophers wrongly believe). This is a direct consequence of the famous Heisenberg Uncertainty Principle. Applied to the Big Bang model, Heisenberg uncertainty predicts that there is no exact point in time called time zero – a trade off between time and energy ensures an in-built fuzziness around this (and any other) instant in time.
The Heisenberg Uncertainty Principle also has implications for the ‘something from nothing’ question. The trade off between time and energy of quantum theory predicts that particles of matter can ‘borrow energy’ to come into existence out of a vacuum, provided their lifetime is short enough. This bizarre behaviour of the smallest constituents of matter has been verified by experiment beyond a shadow of a doubt. Amazingly, it is actually possible in principle that the matter of the entire universe came into being this way, and then had its lifetime extended by a process known as inflation (more on inflation later).
In summary, most cosmologists would argue that there are no real implications for or against religion arising fom the singularity of the Big Bang model, particularly when quantum effects are considered. Indeed, quantum theory even predicts that the entire universe may be a free lunch!