Big Bang 'sounded like jumbo jet'

The Big Bang that gave birth to the universe sounded less like the mother of all explosions than a jumbo jet flying over your house, a US physicist believes.

John Cramer, of the University of Washington in Seattle, has created a computer model of the likely audio frequencies generated by the start to the cosmos.

Research into the Big Bang has earned US scientists John Mather and George Smoot the 2006 Nobel Prize for Physics.

Professor Cramer bases his model on temperature data sent by a NASA satellite, the Wilkinson Microwave Anisotropy Probe (WMAP).

His calculation is based on the frequencies that rampaged through the universe during its first 760,000 years, when it was a cosmic stripling measuring just 18 million light years across.

The frequencies would have been too low to be heard by the human ear, so Professor Cramer has scaled them up 100,000 billion billion times to give an approximation.

His reconstruction can be heard online at: http://www.npl.washington.edu/AV/BigBangSound--2.wav

In a report on Professor Cramer's work, the British weekly New Scientist says the long hum becomes progressively deeper in tone because the sound waves become longer, and thus lower in frequency, as they range across the fast-expanding universe.

- AFP