Geneva scientists use anti-matter to probe origins of Universe

Why matter came to predominate over anti-matter is one of the most perplexing problems of modern physics. CERN Genf

Researchers at the Geneva-based European Organisation for Nuclear Research, or Cern, are planning to create particles of anti-matter, which they say could shed new light on the origins of the Universe and the Big Bang theory.

The scientists have developed a device, called the “Antiproton Decelerator”, which will allow them to make and study particles of anti-hydrogen. It would be the first time that anti-atoms have been slowed down enough to be “caught” and studied.

Anti-matter is currently understood to be the mirror image of conventional matter. Scientists believe that every sub-atomic particle in the Universe has an identical anti-matter equivalent, but one, which has its electrical or magnetic properties, reversed. If a particle of matter were to meet its anti-matter equivalent, so the theory goes, they would annihilate each other in a furious burst of energy.

Scientists have been struggling for years to understand why matter exists at all. In theory, the Big Bang should have created equal amounts of matter and anti-matter, and they should have wiped each other out.

Cern spokesman, Neil Calder, said that resolving this paradox is one of the central challenges of modern physics. “The reaction [between matter and anti-matter] should, by all known laws of physics, have led to the complete destruction of the Universe, since, when the forces of matter and anti-matter clash, they destroy each other.”

The theory that matter and anti-matter coexist first came to light in 1927 when a British mathematician and theoretical physicist, Paul Dirac, formulated an equation that obeyed both quantum mechanics and the laws of special relativity.

He put forward the theory that for every negatively charged electron within an atom, there was a positively charged anti-electron, or positron. Dirac had discovered the concept of anti-matter.

In the early 1930s, in the United States, another scientist, Carl Anderson, announced he had found evidence of anti-matter while studying positive and negative subatomic particles going round in different directions in a device called the Cloud Chamber.

Modern techniques of “catching” anti-matter are about five years old, but what’s new about the Antiproton Decelerator is that it can successfully separate matter from anti-matter, keeping the two apart so that they do not annihilate each other.

The device accomplishes this feat by keeping the “unruly” anti-particles in a vacuum, and cooling them sufficiently so that they are inert enough to study. Anti-electrons are then added to the anti-particles, which then give birth to anti-hydrogen atoms. This allows scientists to investigate the newly created particles of anti-matter.

Although researchers could have chosen any element on which to experiment, hydrogen was chosen because it is the simplest and most abundant element in the Universe.

With funding from 20 European states, the United States and other nations, it is hoped this $15 million (SFr25 million) project will cast light on a monumental mystery that has perplexed the scientific community for over 70 years.

by Lucie Hill