The detection of dark matter may be possible within a decade, a Nobel Prize winning physics professor has claimed.
Underground detectors may "see" dark matter
Professor Carlo Rubbia told a conference in Edinburgh, UK, that this breakthrough would change our view of our place in the cosmos.
"All the visible objects in the Universe... only account for 0.5% of the total, so the Universe as we know it is only a side-show," he said.
Recent estimates suggest about 23% of our Universe is made of dark matter.
Scientists know dark matter must exist because its effects on the movement of galaxies can be measured - but they have no direct observational evidence of dark matter.
Even huge particle accelerators with tunnels several km in diameter have failed to create dark matter particles artificially.
Professor Rubbia, of the Italian National Agency for New Technologies, Energy and Environment (ENEA), told the conference that detectors deep underground might finally provide the proof.
Detectors like those at Boulby in Yorkshire are put in old mines to shield them from cosmic radiation that could confuse the equipment.
The leading dark matter candidates are heavy slow-moving particles known as Wimps (Weakly Interacting Massive Particles) that have been drifting through space since the Universe began.
These sub-atomic particles interact with normal matter only very weakly and are almost impossible to detect in a laboratory on the Earth's surface.
Professor Rubbia thinks a stream of dark matter might constantly be flowing through the Earth and these could be measurable in the underground detectors.
"These cosmic particles are electrically neutral and hardly interact with the ordinary matter," Professor Andy Parker, of the Cavendish Laboratory at Cambridge University, told BBC News Online.
But if one drifts our way the detectors may be able to see it.
Lack of proof
And Professor Rubbia said he was confident that even larger detectors could do the job within the next 10 years.
"The findings would show that the Universe as we know it is just a tiny part of the cosmos. We are maybe even less important in the Universe than we think we are," Professor Parker explained.
He added that scientists were also prepared for the possibility that dark matter might be impossible to detect, even with bigger devices.
"Then we have to sit down again and reconsider our theories about how the Universe is built," he said.
Professor Rubbia was speaking at the 2004 Institute of Physics Nuclear Physics Conference in Edinburgh, UK.