Monday, October 11, 2010
STEPHEN HAWKING’S 1988 book, A Brief History of Time, surprised everybody by becoming a bestseller.
As commitment to religion wanes, people seek alternative answers to fundamental questions. Great thinkers, however, seldom understand the difficulties ordinary mortals have in grasping their lofty ideas and they never use a four-letter word when a 24-letter one will do. Stephen Hawking, although better than most of his peers in this regard, still had a long way to go in 1988 – despite its great success, the Brief History was a difficult read.
His new book, The Grand Design, New Answers to the Ultimate Questions of Life, is much more accessible. Co-authored by Leonard Mlodinow who, one suspects, is responsible for the relative digestibility, its 200 pages are laced with colourful explanations of difficult ideas. This short introduction to relativity theory, quantum mechanics and the current state-of-play in cosmology must be one of the best available. The claim that the laws of physics are sufficient to give rise to the universe without the intervention of God, should ensure a wide readership. It’s not, of course, a new idea: Laplace, when asked about God by Napoleon, famously replied; ‘I have no need of that hypothesis’.
However well presented, the arguments of The Grand Design are not easy to grasp: this in an assault on some very entrenched ideas. Cosmology used to be the preserve of theologians. Then it was the turn of the philosophers. They still regard the field as theirs but, for Hawking, theology and philosophy have had their day. The ultimate questions of existence, he thinks, can’t be addressed by ivory-tower speculation. Only observation, experiment and the processing of vast amounts of data, can shift the frontiers of knowledge; it’s up to the scientists to come up with answers to ‘the great questions’.
Relativity theory, now a century old, played havoc with our notions of time, space and gravity. Its account of the behaviour of large objects, such as planets, stars and galaxies, was a difficult pill to swallow. Arthur Eddington, when asked if he was one of the three people in the world who understood ‘Einstein’s theory’, replied; ‘I am trying to think who the third person is’. But worse was to come. The 1920s and 30s saw the development of quantum mechanics, the science of the very small, the particles of which all objects in the universe, including ourselves, are composed.
In this spooky micro world, even our notions of past present and future collapse. Richard Feynman, chief architect of Quantum Electro Dynamics, once declared; ‘I think I can safely say that no one understands quantum mechanics’. But this, the most tested theory in science, works. Its predictions have been verified. Our universe began with a quantum event; when an infinitely small entity exploded, so quantum behaviour underlies everything.
The current model of the universe involves M-theory, more like a family of ideas than a single doctrine. Each model works in particular areas of enquiry but not in others. None of the component theories covers everything but the doctrines don’t contradict each other. Some of M-theory’s conclusions are bizarre in the extreme. Feynman claimed, for example, that ‘the universe has no single history but every possible history’. M-theory, a candidate for the ‘Theory of Everything’, also predicts that a great many parallel universes exist and that they arose from nothing.
Humanity had to face challenging notions in the past. It seemed self-evident that the Earth is flat. Being told it was spherical upset people long ago. Then came the shock that the Earth is not the centre of the universe but merely a small planet orbiting the Sun. This displeased Pope Urban, who forced Galileo to ‘abdure’ the idea. Next, came the notion that our solar system was just a speck of dust in an enormous galaxy; we were reduced to the status of cosmic nobodies. But our demotion did not end there. It turns out there are billions of galaxies in an ever-expanding universe. Given the history of our discoveries, is the idea of there being countless universes all that surprising?
The Grand Design, New Answers to the Ultimate Questions of Life, by Stephen Hawking and Leonard Mlodinow, (Bantam Press) €13.99.
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