The Times-Tribune

Scientists shine a light on antimatter

Finding important to unraveling mysteries of Big Bang.

- BY FRANK JORDANS

BERLIN — Scientists have used a laser to tickle atoms of antimatter and make them shine, a key step toward answering one of the great riddles of the universe.

Theory predicts that the Big Bang produced equal amounts of matter and antimatter. Since they cancel each other out, scientists have been trying to find out why a relatively small amount of matter remained — allowing the stars, planets and ultimately life as we know it to come about — and antimatter vanished.

It took researcher­s at the European Organizati­on for Nuclear Research, or CERN, decades to figure out how to create an antimatter version of the most basic atom — hydrogen — and trap it for long enough to perform tests.

In a paper published online Monday by the journal Nature, they reported the first cautious result from an experiment with antihydrog­en. It turns out that when it’s stimulated with a laser, antihydrog­en appears to produce light on the same ultraviole­t frequency as its nemesis in the world of matter, hydrogen.

Adding energy — in this case with a laser — to atoms to see what light they absorb and emit is known as spectrosco­py. It is a commonly used tool in physics, chemistry and even astronomy, to determine the atomic compositio­n of substances in a lab or even far-away galaxies. The results can be presented as rainbow-like panels or as graphs showing the distributi­on of certain colors.

“What we have is one color,” said Jeffrey Hangst, a leading member of the team working on the ALPHA experiment at CERN , which is located on the Swiss-French border. “But it’s kind of the most fundamenta­l one because it’s the one that we can measure most accurately.”

Mr. Hangst and his colleagues now plan to refine the experiment, using techniques developed for hydrogen over the past 200 years, to map in precise detail the atomic spectrum of antihydrog­en.

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