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Antimatter captured in major scientific breakthrough Add to ...

Antimatter - elusive and volatile - has been captured for the first time, a major step forward in the study of fundamental physics and the origins of the universe.

An international team of 42 scientists, which included 15 Canadians, have trapped 38 antihydrogen atoms - one by one - for a fraction of a second.

While the experiment itself - conducted at nuclear research lab CERN in Switzerland - is not of Nobel Prize calibre, it could serve as the foundation for future experiments and discoveries of that scale.

The goal is to test fundamental theories of physics and to potentially unravel one of the great mysteries of science. Physicists theorize that there was an equal amount of matter and antimatter created at the Big Bang, yet antimatter somehow vanished.

"It's one of the really big fundamental questions," said Michael Hayden, a physics professor at Simon Fraser University near Vancouver and one of the scientists involved in the experiment.

A paper describing the experiment entitled Trapped anti-hydrogen was published Wednesday online by the science journal Nature.

With champagne uncorked and enjoyed, round-the-clock experiments continue in a race with another team of scientists to conduct precise measurements of antimatter. It is believed that at least 100 antihydrogen atoms need to be trapped at once to really study them in detail.

The team of 42 scientists saw the first indications of successful capture about a year ago and the 38 captures documented in Nature happened in the summer. Recent results - which remain undisclosed - are encouraging, said Prof. Hayden.

"Right now, we're just saying everything is moving nicely in the right direction," he said.

Trapping antimatter is difficult because matter and antimatter do not get on well with each other. In the words of CERN: "They annihilate when they meet." So antimatter must be cooled to about 264 C and slowed down enough to be captured in a trap described as a "magnetic bottle."

The next goal - work is already under way - is to measure "what colour antimatter atoms shine," according to Makoto Fujiwara, a University of Calgary scientist on the team.

Physics theory dictates the colour will be exactly the same as matter. If not, physicists have way bigger challenges on their hands than corralling antimatter.

What is antimatter?

Antimatter, according to team member Jeffrey Hangst of Aarhus University in Denmark, is the "mirror image of normal matter" - in theory identical but opposite. (Thus, if the universe - human beings included - was made of antimatter, it would look and feel the same.)

Antimatter was believed to have existed at the very beginning of the universe but vanished for unknown reasons. Antimatter has been known and studied by modern science for about the past 75 years. A 1955 experiment at the University of California at Berkeley discovered anti-proton, which led to Emilio Segrè and Owen Chamberlain winning the Nobel Prize in Physics in 1959.

Antihydrogen was first observed at CERN in 1995. Experiments in 2002 showed that it was possible to create enough anti-hydrogen that detailed observation experiments were in theory possible, if the atoms could be trapped.

Why toy with antimatter?

The goal of experiments with antimatter is twofold. First, to find out why antimatter vanished, and where it went.

Second, the path to that answer - if it is possible to figure it out - includes comparing and contrasting matter and antimatter. In what's called the "standard model" of physics - involving the structure of space and time, elementary particles and interaction - part of the heart of the theory holds that matter and antimatter behave in the same way.

Now that scientists have trapped antimatter, and can study it in detail, tests of scientific theory are possible. If differences are discovered, fundamental beliefs would have to be rethought.

Fictional antimatter

In the movie Angels & Demons, the sequel to The Da Vinci Code, villains steal antimatter from CERN in a plot to blow up the Vatican. While there is an alluring bomb-and-fuel potential around the explosive nature of matter meeting anti-matter, CERN has two answers. One is that there is "no possibility" of it being used as an energy source, because it would be extremely inefficient. For each unit of energy that goes into producing antimatter, only a tenth of a billionth of a unit of energy results. On the bomb side, CERN says: "[Antimatter]would be very dangerous if we could make a few grams of it, but this would take us billions of years."

Antimatter in real life

Beyond exploration of fundamental physics, an antiparticle called a positron is the key to an increasingly popular imaging technology in nuclear medicine. The technique produces 3D pictures and, in the realm of cancer, it is commonly used to reveal dangerous tumours.

 

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