Part three of The Cosmos and clues to a Creator

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Written by Richard Avery

The Goldilocks Enigma

“Mmmmm, this universe is just right!”

You know the story of Goldilocks? She finds three bowls of porridge in the bears’ house. One is too hot, one is too cold, but the final one was “just right”. In the context of that story it isn’t very surprising that one bowl wad “just right”. Now imagine that Goldilocks was not wandering through a forest, but shipwrecked. She manages to swim to shore on a little island with no sign of human habitation, except for a table with a bowl of porridge and a spoon. And when Goldilocks tastes a spoonful, not only is it good porridge, but the temperature is “just right”. This would be a highly surprising discovery. Enough to make her think someone knew she was coming and prepared the meal to be ready for her arrival.

In the last hundred years astrophysicists have made some remarkable discoveries about the fine tuning of our universe. We now know that for life to flourish, as we see around us on earth, the conditions have to be “just right”. Very slight changes in the laws of nature or the conditions of the early universe and there would be no prospect of a habitable planet nor the necessary chemical building blocks for life. It’s as if the universe was planned in such a way as to facilitate our existence. The technical term for this is the ‘anthropic principle’. (Referring to how suitable the universe is for the emergence of “anthropoi” - the Greek word for human beings).

As astrophysicists and cosmologists have examined the possible ways that a universe might develop from a ‘Big Bang’ start, there are very narrow constraints on the forces of nature and the condition of the early universe, if biological life is to be possible. There are a lot of staggering examples of fine tuning.

The density of matter in the universe in its earliest moments is critical. Slightly smaller and the universe would expand too quickly for stars and galaxies to be able to form. Slightly larger and the universe would re-collapse under gravity in a few months of its existence. The critical density for a fruitful universe has to be accurate to 1 part in 1060 (a million, million, million, million, million, million, million, million, million, million – a very big number indeed!). That’s the accuracy required for a rifle marksman to hit a 10p coin on the furthest edge of the universe, 14 billion light years away.

In fact the present size of the universe, with its 100 billion galaxies each containing 100 billion stars, is necessary for enough time to pass to allow the development of the chemical elements that are the building blocks of all living creatures. In a younger smaller universe, there would be insufficient time to bring about life.

And to have the chemical building blocks of life such as hydrogen, oxygen and carbon requires other very special conditions. The strength of the fundamental forces of nature are determined by the values of the corresponding constants of nature. These must have very particular values in relation to each other for the chemicals of life to be present. If the ‘weak nuclear force’, the force responsible for radioactive decay, were not related to the gravitational force in a very particular way, all the hydrogen atoms in the early universe would be converted to helium within a few seconds of Big Bang. No hydrogen would mean no water and no life. An imbalance in a different direction would leave hydrogen yet inhibit supernova explosions of stars required to make heavier chemical elements.

The early universe only produced two chemical elements: hydrogen and helium. All the rest are made in the nuclear furnaces inside stars. Figuring out how that nuclear factory worked inside stars was one of the great triumphs of 20th Century astrophysics and Cambridge scientist, Fred Hoyle led the breakthrough. Hoyle realised that if the element carbon (the key building block of life) was to be made in stars the force that holds the nucleus of atoms together must be very precisely balanced with electric force between charged particles. And he predicted that there must be a previously undetected energy level in the carbon nucleus such that the right balance of carbon and oxygen would be made in stars. (Without the critical balance, no carbon would be made at all or all of it would burn and make oxygen).

Hoyle’s prediction was confirmed by experimental physicists and he himself, an atheist at the time, is reported to have said that the universe was a ‘put-up job’! Later he wrote about this: “A common sense interpretation of the facts suggests that a super-intellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.

There are many possible examples of fine tuning, some with even more staggering margins of precision than the above. These phenomena stack up to reveal a level of cosmic fine-tuning that has shocked and surprised many scientists. The physical fabric of the universe had to take a very particular form if carbon-based life were to be able to evolve within its history. This is not a proof that the universe has a creator, but if the universe is endowed with such fine-tuned potential, this might indicate that there is a divine Fine-Tuner!

Not all who have pondered these matters conclude that there is a divine Fine-Tuner. A popular suggestion in recent times is that there may be very many different universes, each with very different laws of nature. Just by chance there is one capable of developing life, and that, of course, is our universe. We are just the lucky ticket holders in a ‘multi-verse’ lottery. Multi-verse theories have quite a following in theoretical physics, but they are metaphysical speculation more than science. And, as John Polkinghorne, former Cambridge Professor of Mathematical Physics, has noted, multi-verse ideas are “appealed to, it might seem, partly in order to avoid theism”.

When faced with such powerful evidence of fine-tuning, a divine Creator represents a much simpler and more economical explanation for the existence of our very special universe than the multi-verse hypothesis. Indeed, multi-verse ideas do not resolve the question of the specialness of our universe. (Why does a multi-verse exist and why this multi-verse?). God provides an explanation for why anything exists at all and a reason for the universe being so special as to produce us.

The Goldilocks enigma is not a knock-down argument for belief in God, but it does make a significant contribution to the cumulative case for God’s existence. There is no better explanation for the nature of the world as we know it.

Richard