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Monday, 30 April, 2001, 15:07 GMT 16:07 UK
Astronomers hear 'music of creation'
Cosmic map
Microwave map of the sky: picture of the early Universe
BBC News Online science editor Dr David Whitehouse

Astronomers have detected regular patterns in the so-called afterglow of creation that they say were caused by sound shock waves shortly after the Cosmos was born.

They provide the most precise measurement yet of several of the key parameters that cosmologists use to describe the Universe.

The early Universe is full of sound waves compressing and rarefying matter and light, much like sound waves compress and rarefy air inside a flute or trumpet

Paolo deBernardis
The new results are from a new, more detailed, analysis of images obtained by the Boomerang (Balloon Observations of Millimetric Extragalactic Radiation and Geophysics) experiment.

Boomerang is an extremely sensitive microwave telescope that was carried by a balloon that circumnavigated the Antarctic in late 1998.

The balloon carried the telescope at an altitude of almost 37,000 metres (120,000 feet) for 10 days. Initial images were published a year ago but since then astronomers have been able to carry out a more detailed analysis.

"The early Universe is full of sound waves compressing and rarefying matter and light, much like sound waves compress and rarefy air inside a flute or trumpet," said Italian team leader Paolo deBernardis.

"For the first time the new data show clearly the harmonics of these waves."


Astronomers believe that the Universe was created about 12-15 billion years ago in an explosion called the Big Bang.

The intense radiation that filled the early Universe is still detectable today as a faint glow of microwave radiation known as the cosmic microwave background (CMB) that comes from all directions in space.

Astronomers believe that whatever structures were present at that time would leave their mark imprinted as very faint brightness variations in the CMB.

Boomerang images reveal hundreds of complex regions visible as tiny variations in the intensity of the CMB.

The new results show the first evidence for a regularity in the angular sizes on which the pattern is most pronounced.

The presence of these so-called harmonic peaks bolsters the theory that the Universe grew from a tiny subatomic region during a period of violent expansion a split second after the Big Bang.

"Just as the difference in harmonic content allows us to distinguish between a flute or trumpet playing the same note, so the details of the harmonic content imprinted in the CMB allow us to understand the detailed nature of the Universe," said Dr Barth Netterfield, of the University of Toronto in Canada.

Creation 'music'

In their first release of data, in April 2000, the Boomerang team was able to reveal only one harmonic peak.

Now, according to Andrew Lange, of the California Institute of Technology, Pasadena, they can see more.

"Using a music analogy, last year we could tell what note we were seeing - if it was C sharp or F flat," he said.

"Now, we see not just one, but three of these peaks and can tell not only which note is being played, but also what instrument is playing it - we can begin to hear in detail the music of creation."

The images obtained cover about 3% of the sky. The researchers plan another campaign to the Antarctic in the near future, this time to map even fainter images encoded in the polarisation of the cosmic microwave background.

The scientific payoff of such measurements "promises to be enormous", said John Ruhl, of the University of California at Santa Barbara.

"With today's results we know for sure that the music is there and we can interpret it.

"There is no doubt that by listening carefully, and in new ways, we will learn even more."

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12 May 00 | Sci/Tech
Close-up on the early Universe
28 Apr 00 | Sci/Tech
Pictures of the early Universe
26 Apr 00 | Sci/Tech
Universe 'proven flat'
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