Sitting in the audience and listening to the responses, he knew he had been controversial and awaited the learned responses with interest. The responses were not as subtle as he had expected.
When Alan Guth, a professor of physics at the Massachusetts Institute of Technology, one of America’s leading research universities, took the podium, he pulled no punches.
The conference, organised by America’s National Academy of Sciences, froze in embarrassment as Guth attacked Turok and his theories — and called up a slide of a monkey to illustrate his comments.
“I was shocked,” said Turok. “I had been putting forward a new idea about what happened before the Big Bang and the events that led to the creation of our universe. Depicting me as a monkey was his way of saying I was wrong.”
That event was just one salvo in what has become one of science’s fiercest debates: how to explain the origins of the universe. What Turok had done in his lecture and accompanying papers was to challenge an idea that has held physicists in thrall for more than four decades: that time, space and everything else all appeared out of nothing and began with one Big Bang.
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Instead, Turok says the Big Bang was not a unique event at all. In fact it was likely to have been one of many, perhaps millions of, Big Bangs.
A small but growing band of other researchers, including Paul Steinhardt, the Albert Einstein professor of science at Princeton University, support the idea.
If Turok and his supporters are right, the implications are daunting. The life’s work of many scientists, and thousands of research papers, would be redundant. No wonder they are fighting back. It would also mean that time, matter and energy have always existed — and always will.
It was Albert Einstein who put science on the trail of the Big Bang when his general theory of relativity made it clear that the universe could expand or contract.
Einstein never worked out which it was doing, but 14 years later the American astronomer Edwin Hubble made the historic discovery that, wherever one looked in space, galaxies were racing away from each other.
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The clear implication was that if things are flying apart now they must once have been much closer together — and that perhaps they all began at one single, tiny point.
From this combination of theory and observation grew the idea of the Big Bang which, in its current form, suggests that the universe exploded into existence 13.7 billion years ago.
The Big Bang theory has a lot going for it. It fits with the observed expansion of the universe, the age of the oldest stars and the ratio of light and heavy elements found around the universe.
The idea has gathered support outside science too, partly because it suits the creation myths of many religions including Christianity, Judaism and Islam. Pope Pius XII, then head of the Catholic church, even began preaching Big Bang theology in the 1950s, although he urged researchers not to probe the Big Bang itself, suggesting that the moment of creation was “the work of God”.
Pius was prescient. He had put his finger on the very problems that are still troubling many cosmologists today. The universe may have begun with a Big Bang — but where did that come from? What caused it? And was it unique?
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IN THE 1970s Guth was one of those who realised that the Big Bang theory failed to explain how a hot chaotic fireball could become the cool universe with stable clusters of galaxies we see today.
Rather than challenge the idea that time and space began with the Big Bang, he suggested the new universe had suddenly expanded trillions of times in a millionth of a second. That idea, called inflation, did such a good mathematical job of explaining the shape of the universe that it was adopted far and wide.
Guth himself has built his career on it. Recently, however, it has become clear that the theory has major flaws. There is, for example, no widely accepted way for physics to explain how such “inflation” could have happened.
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It also fails to deal with the 1990s discovery of “dark energy”, the energy field that fills all space and which is now thought to be the cause of the universe’s expansion.
()For Turok and others, such failings have become too much to live with. “The supporters of inflation have become too evangelical. They have no idea why inflation happened but they still believe in it,” he declares.
Under his and Steinhardt’s theory, the Big Bang was not the beginning of history but simply an event within it, caused by the collision of our universe with another one existing in another dimension.
Turok and Steinhardt suggest that such events may happen every trillion years in a kind of cycle. If they are right, then time has always existed and so has the universe. What’s more, they always will exist, and so there is no need for inflation or for a creation event — or perhaps even a creator. Pope Pius would be furious. Many of Turok’s fellow physicists already are.
To those outside physics, Turok’s and Steinhardt’s ideas may sound radical, but some cosmologists have long recognised that they offer solutions to many of the problems thrown up by the standard Big Bang theory.
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Among them is Professor Stephen Hawking, a close colleague of Turok’s in the Department of Applied Mathematics and Theoretical Physics at Cambridge University.
Hawking has suggested that space could have up to 11 dimensions; that our universe could exist inside a “higher dimensional space” that contains one or more other universes; and he has proposed the existence of “shadow worlds” whose presence might only be revealed by tiny fluctuations in our universe’s gravitational background.
These ideas are the basis of the new theory. This week Hawking will give a keynote speech on the subject at an international conference in Cambridge he has co-organised with Turok.
OTHERS remain sceptical, if not scathing. Andrei Linde, professor of physics at Stanford University, is a long-standing opponent. At one conference he drew a caricature of a key U-shaped graph used by Turok and drew a cut through the U — which was taken by Turok’s supporters as implying castration. It was meant as a joke but it had a hard edge.
Linde said: “Turok and Steinhardt’s model has many problems and the authors made quite a number of errors, which is why it is not very popular among cosmologists.”
The academic world is often thought to be one of reasoned debate rather than vitriol. What is driving the heated emotions? Peter Woit, an advanced maths lecturer at Columbia University, believes he has an explanation for the present fury: the physicists are simply getting bored.
“The problem is that it is taking an increasingly long time to solve cosmological problems,” he said. “Early last century all you needed was a good telescope or radio equipment. Now you need to design and build satellites, which can take over a decade.
“It means many years can elapse between a theory appearing and getting the means to test it, and all the theorists can do during that time is argue. That is what’s happening now.”
Next year some of the arguing may be brought to a halt when the European Space Agency launches its Planck satellite whose mission will include searching for tiny fluctuations in the temperature of the cosmic microwave background — the echo that theorists say has been left by the Big Bang.
If they find such ripples it will be powerful evidence in favour of Guth’s theory of inflation. If they don’t, then Turok’s and Steinhardt’s ideas may become the new orthodoxy — one in which universes collide.
THEORIES THAT CAME AND WENT
Science is littered with once-dominant theories that have either been discarded or come under fire. Some of the most famous theories include:
THE ETHER
The ancient Greek philosopher Aristotle hypothesised that space was filled with invisible ether. This, he said, explained how light could travel across empty space. The theory survived 2,000 years until two American scientists in 1887 proved ether did not exist
CANALS ON MARS
The American astronomer Percival Lowell put forward the idea of canals on Mars, writing three books with maps. Lowell’s work gave rise to the long-held belief that Mars sustained intelligent life forms
AGE OF THE EARTH
The influential Victorian physicist Lord Kelvin asserted the Earth was just 100m years old. It was only when scientists were able to measure the age of rocks from their radioactivity that they found our planet’s age is 4.5 billion years
DARK MATTER
Many physicists argue that, to make current theories work, much of the universe must be made up of “dark matter” that we cannot see. However, it has never been found or measured; some scientists now suggest it may not exist
STRING THEORY
For two decades the idea that matter is made up of tiny strings, rather than point-like particles, has dominated cosmology. But two forthcoming books by top scientists attack the theory. Lee Smolin, one of the authors, now describes string theory as a “dead end”