Scientist questions theory of universe's origins

By SIMON COLLINS science reporter

Two years after the death of the great British astronomer Fred Hoyle, his colleague Jayant Narlikar is still unconvinced that the universe started with a single "Big Bang".

Dr Narlikar, an Indian astrophysicist who co-wrote four books with Hoyle, has dusted off Hoyle's rival theory of a "steady-state universe" and updated it with new evidence.

"The alternative we have proposed is that the universe is without a beginning and without an end," he said in Auckland this week.

"It has ups and downs, or oscillations. It expands and contracts - not to nothing, but to a small size, so the universe would be 200 to 300 times more dense when at its maximum density. But it's not infinitely dense."

In polite astronomical circles, his view is a heresy. Dr Grant Christie, who introduced Dr Narlikar's Burbidge Lecture at Auckland University on Wednesday, said the evidence that the first matter was created in a Big Bang about 14 billion years ago was "overwhelming".

"The predictions are being tested experimentally and found to be in quite good agreement, so generally the mainstream is quite relaxed about the fact that the Big Bang is more or less right," Dr Christie said.

But, Dr Narlikar argues, those "predictions" have been modified several times to fit the actual observations of the universe.

More than 20 years ago, scientists realised that there was a basic flaw in the original Big Bang theory because it required initial expansion in the first few fractions of a second at a speed faster than the speed of light. That would have meant that some parts of the universe could not have been subject to the laws that make the speed of light the same everywhere.

But in fact, observation suggests that the same laws do apply throughout the universe.

To get around that, Big Bang theorists invented the idea of a kind of cosmic "inflation" in which the universe expanded slowly in the first few fractions of a second in which the basic universal laws were established, then suddenly picked up enormous speed for a while before settling back into its current rate of expansion.

"Is the physics of inflation tested?" Dr Narlikar asked.

"Has inflation been directly observed? Is it repeatable and observable at other times and places?"

The answer to all three questions, he said, was "No."

And that was just the first problem. Next, scientists realised that there must be far more matter in the universe than they could see to explain their observations of stars and galaxies.

First they invented the idea of invisible "dark matter". Now the mainstream view is that 97 per cent of the stuff that exists in the universe is either dark matter or the even more elusive "dark energy".

Dr Narlikar said it was all "speculation".

He says a simpler explanation is that the universe expands and contracts in roughly 50 billion-year cycles

Since he agrees that the current expansion began about 14 billion years ago, "we are about a quarter of the way through the cycle".

"The creation of matter is the main source of expansion, and it switches off once in a while because the system has feedback mechanisms so it can't go on creating all the time," he said.

"When it creates matter, it expands faster and faster, and the force causing it becomes less and less dense when it expands.

"When the force becomes weak, creation stops, and the universe starts to contract. It gets weaker because of its rapid expansion, so expansion is a feedback which makes the force weak."

The implication is that the universe has always existed and always will, endlessly growing and collapsing.

Dr Narlikar says that only the human need to explain things led to the invention of a single moment of creation, whether it was in the seven days of the Book of Genesis or an instantaneous Big Bang.

As a scientist, he says that his "quasi-steady-state" theory can be tested because it holds that in the shrinking phases, the universe merely shrinks to a much smaller size but never actually disappears.

Therefore stars that existed in earlier cycles must have been crushed together in the contractions, but not eliminated.

"Some of those old stars should be left out there today. We should look for them," he said.

He admits that his latest theory may be wrong, too. But, he argues, "We need some competing theories.

"At the moment, people take everything on trust.

"My argument is that we should do repeatable tests and see whether the Big Bang is right.

"At the moment, that kind of critical testing is not being done."

Did the Big Bang happen?

Most scientists believe the universe began 14 billion years ago in an explosion known as the "Big Bang".

Sceptics say: The explosion would have begun faster than the speed of light, which is theoretically impossible.

The theory cannot account for a missing 97 per cent of the universe known as "dark matter".