Date: 27 July 2003
Subject: Stars

Working, as I do, in a university department of physics, astronomy and mathematics, I am bound to have some passing interest in astrophysics - albeit not at all an expert one.

The history of the development of astrophysics is fascinating - many of the pioneers (Herschel, Huggins, Maunder etc) had sincere Christian beliefs, and certainly none of them though of themselves as somehow undermining Christian faith. The trick was to try to infer the history of the stellar universe from its present features, which may seem a bit like trying to build up a picture of the lifecycle of an organism from a snapshot of its members at possibly different ages. This does not mean, however, that it is nothing more than guesswork. Forensic scientists deduce things about the past from present situations, and some of the physics models used in astrophysics have become increasingly corroborated.

Current views of the "big bang" (a theory which we need to keep in mind was first advocated by a Belgian priest not by any atheist) are that it occurred some 13.7 billion years ago. The very early universe consisted mostly of hydrogen and helium, and he earliest stars were gigantic fast-burning bodies with no heavy elements. Heavy elements were formed by nuclear reactions in these early stars, a process possible only because of some extraordinary "fine tuning" in nature. Any stars we now see, however, which lack heavy metals, could be relics of that primeval past. So how can we tell the content of stars so far away? One of the exciting developments in the nineteenth century was spectroscopy. As elements emit or absorb a characteristic colour of light when burning, we can tell from analysis of the light from distant stars what their composition is. It turns out that one of the stars in our own galaxy (unexcitingly called HE 0107-5240), only 36,000 light years away, is very short of heavier elements. A "yellow giant", it turns out to contain 200,00 times less iron than the sun, and 200 times les than the previously lowest known star. Astrophysicists estimate, therefore, that it may be up to 13.5 billion years old.

Christians may have two negative reactions to such theories. The first is to pooh pooh them as mere conjecture, probably motivated by anti-God sentiments. This is not very realistic. It is, of course, possible that parts of modern astrophysics are mistaken, but it seems highly unlikely that all my colleagues (including Christian ones) are so totally deluded that all their models are calculations are out by millions of percent.

The other negative reaction is fear and dismissal. The numbers are so large that our minds can scarcely conceive them. This is not a proper and biblical Christian reaction. When the psalmist considered the heavens, he was certainly struck with great awe and wonder. This did not, however, lead to fear or dismissal, but to worship at the thought that the God who made this could also be a personal God who cared for human individuals. The complexity of the system by which heavier elements were generated (requiring billions of years) should simply make us the more aware of the value of the final outcome - the possibility and then the actuality of physical beings like us who can think and reflect on the process.