COSMIC TRUMPET

Tim Radford, science editor
Thursday April 15, 2004
THE GUARDIAN

The universe - all that ever was, is or will be - could literally be a horn of plenty, according to German cosmologists. The cosmos could be stretched out like a long trumpet, infinitely long and narrow at one end, finite but flaring out like a horn at the end that humans can see now.

This is the shape of creation, known as a Picard topology, that makes most sense to Professor Frank Steiner, a theoretical physicist at the University of Ulm in Germany.

According to New Scientist today, a funnel-shaped universe best explains the pattern of cosmic background radiation observed when the universe was only about 380,000 years old.

This picture of early radiation, made by Nasa's Wilkinson microwave anistropy probe last year, has already helped answer some key questions about the history of time, space and everything. It helped pin the moment of creation to around 13.7 bn years ago. It helped confirm the proportions of the universe as 4% matter, 23% dark or undetectable matter and 73% something mysterious called quintessence, vacuum energy or dark energy. And it has raised once again the vexing question of the shape of the universe.

Even before cosmologists knew about the Big Bang, they had started worrying about the shape of spacetime. Did it stretch on forever, or was there a boundary? Einstein played with the idea of a negatively curved or saddle-shaped universe. Others wondered if it might be toroidal or doughnut shaped, so that it would seem to go on forever.

Last year, a New York team speculated that the universe might really be quite small, but shaped like an endlessly repeating set of dodecahedrons or soccer balls, so that a journey of 60bn light years in one direction would bring a traveller back to Earth, like a circumnavigation of the globe. Light travels in a straight line through space, but if space was crumpled or folded back on itself, galaxies might be quite close.

Prof Steiner's universal horn is another possible answer to the great spacetime riddle. A spacecraft could go on forever - but if it reached the flared end of the horn, it would start travelling back in on the opposite side. This shape is not the onlyrecent suggestion: a few months ago, a Pennsylvania team proposed a universe that looked like a squashed sphere.

"I made the comment that it is as though God carefully made the universe and then dropped it," says Paul Davies, a cosmologist now based at Macquarie University in Australia. "Until now, most serious cosmological models have assumed simple geometries and topologies: spatially flat and infinite, saddle-shaped and infinite or spherical and finite.

"But that hasn't stopped theorists exploring the properties of all sorts of weirdo shapes. Anyway, the universe can have a shape and still be infinite."

=================================================

By Dr David Whitehouse
BBC News Online science editor

Astronomers have detected sound waves from a super-massive black hole. The "note" is the deepest ever detected from an object in the Universe.

The black hole lives in the Perseus cluster of galaxies, located 250 million light-years away.

The tremendous amounts of energy carried from the black hole by these sound waves may solve a longstanding problem in astrophysics.

The pitch of the sound can be determined. Although far too low to be heard, it is calculated to be B flat.

Beyond hearing

Last year astronomers obtained an image from the orbiting Chandra X-ray telescope showing ripples in the gas filling the Perseus galactic cluster.

According to the researchers the ripples are evidence for sound waves that have travelled hundreds of thousands of light years from the cluster's central black hole.

But a human would have no chance of hearing it because the note is 57 octaves lower than middle-C.

With a frequency over a million, billion times deeper than the limits of human hearing, it is the deepest note ever detected from an object in the Universe.

"The Perseus sound waves are much more than just an interesting form of black hole acoustics," says Steve Allen of the Institute of Astronomy in Cambridge, England.

"These sound waves may be the key in figuring out how galaxy clusters, the largest structures in the Universe, grow."

Sustained note

Astronomers are puzzled because there is so much hot gas in galaxy clusters and so little cool gas. The hot gas should cool, and the dense central gas should cool the fastest.

Then the pressure in this cool central gas should fall, causing gas further out to sink in towards the galaxy, forming trillions of stars along the way. But this is not what is seen.

Heating caused by a central black hole has long been considered a good way to prevent cluster gas from cooling.

Previous Chandra observations of the Perseus cluster showed two vast, bubble-shaped cavities in the cluster gas extending away from the central black hole.

Sound waves spreading out from the cavities could provide the much sought after heating mechanism.

Researchers calculate that a tremendous amount of energy is needed to generate the cavities, as much as the combined energy from 100 million exploding stars.

Much of this energy could be carried by the sound waves that should keep the gas warm. If so, the B-flat pitch of the sound wave, 57 octaves below middle-C, would have remained roughly constant for about 2.5 billion years.

================================

God is SO big that when he plays HIS low C on HIS celestial Bb TRUMPET it sounds 57 octaves below middle-C, and his 20 minute CAT ANDERSON long note routine lasts 2.5 billion years.

: ) ------ Roddy o-iii<O