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A long-standing goal of science is to be able to understand how matter behaves at the atomic and subatomic level. How electrons rearrange when atoms or molecules come together is the essence of chemistry, and the ability to manipulate those rearrangements is the goal of the emerging sphere of nanotechnology. A fuller understanding could lead to enormous scientific and technological breakthroughs. Unfortunately, significant problems confront scientists and engineers in attacking the question. Not only are atoms and molecules very small, requiring highly specialized equipment to "see" them, everything at the atomic level happens very, very fast. For example, an electron goes around the nucleus of an atom once every 150 attoseconds -- that's around one 10 millionth of a billionth of a second, far too quick for the human eye or any existing equipment to detect. Scientists have a good understanding for simple chemical combinations, but not for complex entities like biological molecules. And nanotechnologists essentially operate in the blind in the sense that they are not yet able to watch while the nanostructures they construct are being assembled. They only know if they have succeeded after the fact. Nothing exists to allow scientists and engineers to see those electronic processes, but University of Nebraska-Lincoln physics graduate student Hua-Chieh Shao and his adviser, theoretical physicist Anthony Starace, have modeled a four-dimensional imaging technique that could lead to a breakthrough. They report their findings this week in the online edition of Physical Review Letters. Their paper will appear in the Dec. 31 print edition of the journal. The research was supported in part by funding from the National Science Foundation and the Nebraska Research Initiative.