27 November 2010 Last updated at 10:30 GMT

Cosmos may show echoes of events before Big Bang
By Jason Palmer Science and technology reporter, BBC News

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Evidence of events that happened before the Big Bang can be seen in the glow of 
microwave radiation that fills the Universe, scientists have asserted.

Renowned cosmologist Roger Penrose said that analysis of this cosmic microwave 
background showed echoes of previous Big Bang-like events.

The events appear as "rings" around galaxy clusters in which the variation in 
the background is unusually low.

The unpublished research has been posted on the Arxiv website.

The ideas within it support a theory developed by Professor Penrose - knighted 
in 1994 for his services to science - that upends the widely-held "inflationary 
theory".

That theory holds that the Universe was shaped by an unthinkably large and fast 
expansion from a single point.

Much of high-energy physics research aims to elucidate how the laws of nature 
evolved during the fleeting first instants of the Universe's being.

"I was never in favour of it, even from the start," said Professor Penrose.

"But if you're not accepting inflation, you've got to have something else which 
does what inflation does," he explained to BBC News.

"In the scheme that I'm proposing, you have an exponential expansion but it's 
not in our aeon - I use the term to describe [the period] from our Big Bang 
until the remote future.

"I claim that this aeon is one of a succession of such things, where the remote 
future of the previous aeons somehow becomes the Big Bang of our aeon."

This "conformal cyclic cosmology" (CCC) that Professor Penrose advocates allows 
that the laws of nature may evolve with time, but precludes the need to 
institute a theoretical beginning to the Universe.
Supermassive find

Professor Penrose, of Oxford University, and his collegue Vahe Gurzadyan of 
Yerevan State University in Armenia, have now found what they believe is 
evidence of events that predate the Big Bang, and that support CCC.

They looked at data from vast surveys of the cosmic microwave background - the 
constant, nearly uniform low-temperature glow that fills the Universe we see.

They surveyed nearly 11,000 locations, looking for directions in the sky where, 
at some point in the past, vast galaxies circling one another may have collided.

The supermassive black holes at their centres would have merged, turning some 
of their mass into tremendous bursts of energy.
WMAP data The microwave background has, on average, only minor variations

The CCC theory holds that the same object may have undergone the same processes 
more than once in history, and each would have sent a "shockwave" of energy 
propagating outward.

The search turned up 12 candidates that showed concentric circles consistent 
with the idea - some with as many as five rings, representing five massive 
events coming from the same object through the course of history.

The suggestion is that the rings - representing unexpected order in a vast sky 
of disorder - represent pre-Big Bang events, toward the end of the last "aeon".

"Inflation [theory] is supposed to have ironed all of these irregularities 
out," said Professor Penrose.

"How do you suddenly get something that is making these whacking big explosions 
just before inflation turns off? To my way of thinking that's pretty hard to 
make sense of."

Shaun Cole of the University of Durham's computational cosmology group, called 
the research "impressive".

"It's a revolutionary theory and here there appears to be some data that 
supports it," he told BBC News.

"In the standard Big Bang model, there's nothing cyclic; it has a beginning and 
it has no end.

"The philosophical question that's sensible to ask is 'what came before the Big 
Bang?'; and what they're striving for here is to do away with that 'there's 
nothing before' answer by making it cyclical."

Professor Cole said he was surprised that the statistical variation in the 
microwave background data was the most obvious signature of what could be such 
a revolutionary idea, however.

"It's not clear from their theory that they have a complete model of the 
fluctuations, but is that the only thing that should be going on?

"There are other things that could be going on in the last part of the previous 
aeon; why don't they show even greater imprints?"

Professors Penrose and Cole both say that the idea should be shored up by 
further analyses of this type, in particular with data that will soon be 
available from the Planck telescope, designed to study the microwave background 
with unprecedented precision.
Planck data (Esa) Planck will provide a plethora of data that may prove or 
disprove the idea
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