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The Physics of Christianity

Comments by Gordon Peckham

The Physics of Christianity by Frank J Tipler (2007, Doubleday, £12.43 hardback from Amazon) is reviewed by Edwin Cartlidge in Physics World, May 2007. Tipler, a professor of mathematical physics at Tulane University in New Orleans and author of The Physics of Immortality, believes that cosmology proves the existence of god. He interprets the bible in a rather literal sense and believes that science can explain the Christian miracles. For instance he suggests that the resurrection can be explained by the body of Jesus being converted almost instantaneously into neutrinos – the reviewer restrains his comment to "Needless to say, these claims will not be met with universal approval by other physicists".

In the same issue of Physics World, George Ellis reviews God, the Failed Hypothesis: How Science Shows That God Does Not Exist by Victor J Stenger, emeritus professor of physics at the University of Hawaii (2007, Prometheus Books, £13.99 hardback from Amazon). The reviewer is not impressed: "… Immanuel Kant and David Hume emphasized two centuries ago that attempts to conclusively prove either the existence or non-existence of God by such reasoning could not work." The book claims that the mind is determined by physical processes; there is no scientific evidence for a soul. The reviewer comments "This is the strongest argument the author puts forward for the non-existence of God as it relates directly to a number of religious claims and is plausible in terms of present-day neuroscience. However, it is certainly not a scientific proof, as we have not solved the hard problem of consciousness, and do not even know how to begin tackling it."

There is no strict proof either way; you can suppose all sorts of unlikely scenarios which cannot be disproved. Bertrand Russel wrote in an article Is there a god?:

If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is an intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense. If, however, the existence of such a teapot were affirmed in ancient books, taught as the sacred truth every Sunday, and instilled into the minds of children at school, hesitation to believe in its existence would become a mark of eccentricity and entitle the doubter to the attentions of the psychiatrist in an enlightened age or of the Inquisitor in an earlier time.

Pierre-Simon Laplace, in reply to Napoleon who had asked why he hadn't mentioned God in his book on astronomy, is supposed to have commented "Je n'avais pas besoin de cette hypothèse-là" ("I had no need of that hypothesis").

Behind all this argument is the question of what we mean when we assert that something exists. The Concise Oxford English Dictionary defines to exist as to "have objective reality or being", but this simply sidesteps the question – what is 'objective reality'? For everyday objects which impinge directly on our senses there is not much doubt about what we mean – everyone can agree that there is a table in the room. But, when we get to some of the entities of scientific theories things are not so clear cut. Around 1800, John Dalton reintroduced the atom to explain the constant ratios of the masses of elements in chemical compounds, but the atomic nature of matter was not generally accepted for another 50 years until atoms were shown to be useful in explaining a wider range of phenomena (e.g. the pressure of gases, Brownian motion). What about the fundamental building blocks of matter postulated in modern physical theory – quarks, strings – do these exist? Norman Gray discusses this question in Fundamental Physics and the Nature of Reality. It has to be recognised that these entities depend on our theories of matter and we have no comprehensive, consistent 'theory of everything'.

In the end does it really matter whether such entities 'really exist' or not? We use science to manipulate the world – what we believe about 'ultimate reality' is irrelevant. Perhaps an entity can be said to exist simply because it is useful in some model of reality. You may think that this definition is too weak, but think about it. Maybe we should not apply the 'law of the excluded middle' which would insist that something either exists or does not exist. This law causes many philosophical problems – e.g. the angst Christians have about the supposed moment of ensoulment of a child.

Perhaps god exists if he/she is a useful concept in some model of reality. You can make up your own mind.