THE UNIVERSE WITHIN,
by Neil Turok,
Allen & Unwin, 294pp.
Our oldest creation stories try to describe the universe in the language and ideas available to our ancestors. Later ancestors developed ways of thinking more systematically, some of them developing descriptions of the universe that relied less on metaphors drawn from human society.
They wanted rules of explanation that could apply universally in the known material world, as well as providing some order to the inferred spiritual dimensions that we use to fill our gaps in understanding.
This quest has never ended, though cultures often try to defend orthodox cosmologies based on theories and methods that have been superseded. Scientific cosmologists can be almost as stubborn as religious conservatives in denying new ideas. When the shouting dies, it all comes down to Physics.
How readily our eyes sparkle with awe when we look at a starry sky on a clear night, or view vivid images of near-infinite space captured by the latest space telescope. But how rapidly they glaze over when a beady-eyed enthusiast explains how every phenomenon can be described as an interaction of cosmological forces that, though barely understood, can be described in mathematical formulae. Are you still with me?
I once read Prof. Stephen Hawking’s A Short History of Time and thought I understood most of it, then fled the topic, never to return. As a young publisher’s assistant, I proofread another professor’s book on Einstein’s Theories of Relativity. I thought I understood that, too, but wouldn’t claim to now.
Neil Turok has taken on a much wider topic than Hawking. Turok held a chair in mathematical physics at Cambridge and published, together with Hawking, a theory on how universes come into existence. That’s universes, plural. He now heads the Perimeter Institute in Canada, which supports the study of theoretical physics and campaigns for wider community understanding of what physicists are on about, and why it matters.
His title The Universe Within tells us this book addresses a vast topic from a human perspective. It is about the ways that generations of scientists have revised and renewed theories and observations on what governs the past, present and future of our universe. Within, it is about how human minds grapple to understand the infinities and imponderables of all matter and energy, from smallest sub-atomic energy states to the possibly infinite multiplicity of universes that share time and space with everything we humans are able to observe.
There is a quick review of ancient philosophical ideas about the universe, and of the development of mathematics as a way to describe and analyse observations. Mathematics, applied to physics, then allowed philosophers and scientists over the centuries to develop and extend theories into concepts for which there was, as yet, no evidence.
Newton’s physical laws were, and remain, good enough for most earth-bound mechanical purposes, but later discoveries about the nature of light, electricity, magnetism and gravity added vital dimensions to speculation about space, time and infinity. Einstein and many others could describe fixed mathematical relationships between fundamental matter and energy, seeming to explain most of what was observable in human experience. Einstein determined that energy and mass are locked in a relationship governed by the square of the speed of light, but this is far from the only foundation formula.
Turok puts forward a far longer formula that “summarizes all the known laws of physics”, in symbols only a mathematician could love. The secret is that, like the pronouncements of ancient oracles, the relationships within the formula are generally accepted, but the values represented by most of the symbols are themselves often contested or unknown.
The one principle that nobody challenges is that no theory is beyond challenge.
The latest and best observations support the theory that our universe is expanding at an accelerating rate, having started as a microscopic dot of unbelievably compressed energy some 4-5 billion years ago. The expansion, and therefore the entire universe, is probably powered by the dark matter and “vacuum energy” that was validated by our local Nobel hero Prof. Brian Schmidt and his colleagues, perhaps catalysed by the very Higgs Boson particles that have recently been validated by the Large Hadron Collider experiments in Switzerland. It is not the job of physicists to ask why this happened, but they are increasingly confident that they know how it happened. There are still strenuous arguments among physicists, but Turok inclines to the view that our current expanding universe is just one instance of an infinite number of expansions, followed after a few billion years by contraction, and then another Big Bang to start the expansion again.
A lot of this seems disconnected from human experience because mathematical reasoning is not the same thing as common sense. Indeed, Turok explains that much of the essential theorizing depends on the use of special numbers and terms that are themselves “irrational” or “unreal”: for example the letter i, representing the square root of -1, is essential to the resolution of many critical formulae, though you could never find such a value in daily life. Similarly, the theory of infinite bangs and busts depends on a concept called “imaginary time”.
The greatest conceptual leap takes us from classical physics to the realm of quantum mechanics. In this framework the world, indeed the universe, is in constant flux and the state of everything is in constant change. There is no truth, only probability. There can be no absolute measurement, only observation. The job of physicists is to provide, from their observations, theories with reasonable probability. In some such theories, the existence of our own universe is almost at the lowest level of probability. However, because the number of possibilities is infinite, sooner or later our universe would be bound to pop up. After some moments of horror, I received this with relief. Probability makes more sense than certainty to the human brain.
Turok suggests that the application of quantum principles to computing will multiply the subtlety and speed with which future machines can make calculations on our behalf. They really will be more like human (analog) brains than those relatively moronic binary computers we now use, that must build every step of their logic from choices of absolute yes or no. For quantum computers, every value will always be “somewhat”. I think I can relate to that.
The bravest thing about this book is that comprises the scripts of five orations originally broadcast as the Canadian Broadcasting Corporation’s flagship Massey Lectures for 2012. Neil Turok has done his best to leaven it with anecdotes and metaphors. I was baffled by an explanation of gravity using an image of two people standing on ice hockey pucks – in space. How such dense and often challenging material can be absorbed via hour-long radio lectures must be a matter of quantum uncertainty. For a lay reader like myself, the material is hard work but definitely rewarding.
Richard Thwaites has maintained a cautious interest in scientific cosmology since reading John Milton’s Paradise Lost as a teenager.