Sci­en­tists shine a light on an­ti­mat­ter

Find­ing im­por­tant to un­rav­el­ing mys­ter­ies of Big Bang.

The Times-Tribune - - Health & Science - 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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