Images show atoms moving in molecule


AFP

PARIS–Scientists on Wednesday said they had recorded the first real-time images of atoms moving in a molecule, a feat that captured movement lasting less than one millionth of a billionth of a second. The exploit entailed directing an ultra-fast laser onto molecules of nitrogen and of oxygen. Its pulse of light knocked a single electron out of its orbit around one of the atoms. The electron tumbled back onto the molecule, causing a tiny collision that, like ripples in a pond, proved a “backlight” of energy. Sensors picked up a movement of joined atoms vibrating. The research, published in the journal Nature, was headed by Louis DiMauro, a professor of physics of Ohio State University. The molecules that were studied are very simple — oxygen and nitrogen make up most of the atmosphere — but the hope is to progress to imaging of more interesting fare. Drug designers could be among the beneficiaries. “You could use this to study individual atoms,” DiMauro said in a press release. “But the greater impact to science will come when we can study reactions between more complex molecules. Looking at two atoms — that’s a long way from studying a more interesting molecule like a protein.” In a separate technical breakthrough, also reported in Nature, physicists at CERN used microwaves to manipulate “anti-matter” atoms, once a staple of sci-fi but now one of the big frontiers of particle research. In theory, there should be equal amounts of matter and its opposite, known as anti-matter, as a result of the Big Bang that created the cosmos. But clearly there is not, otherwise the physical Universe would not exist. When a matter atom meets an anti-matter atom, they cancel each other out in a burst of energy. So, for some reason, there is a far greater abundance of matter than anti-matter. Scientists poring over this mystery have labored to find out more about elusive anti-matter atoms.

In recent years, they have isolated anti-atoms and then stored them — but handling them is a fiendishly hard task, given the risk of destroying them through mere contact. The latest achievement, led by the so-called ALPHA team at CERN (European Center for Nuclear Research) in Geneva, entailed confining antihydrogen atoms in a magnetic trap and bombarding them with microwaves. The energy kick forced the atoms out of the trap, providing some vital clues about their properties — an “anti-atomic fingerprint,” in the scientists’ words.