Sometimes difficulties turn out to be blessings in disguise – especially in research. An excellent example is the story of how crystals that were too bent for their intended purpose inspired the use of deliberately bent crystals to resolve properties of X-ray pulses.
Researchers at the Stanford Linear Accelerator Center (SLAC) reported that custom ultra-thin silicon crystals were ordered for an instrument in an effort to split X-ray pulses from SLAC’s Linac Coherent Light Source (LCLS). Researchers needed near perfect crystals to obtain precise measurements on a pulse-by-pulse basis to correctly obtain the best results. It was discovered that one batch of silicon crystal samples they received unfortunately had wrinkles, apparently bent during their processing. Measuring the curvature led these researchers to an important breakthrough. When they sent LCLS pulses through a bent crystal, they were able to divert a small part of the light and break it into its component wavelengths for color analysis while the bulk of the light went downstream for experiments.
Like a beautiful sunset, the wobble of the moon, or the formation of a cloud, simple systems we are familiar with cannot be predicted because they are sensitive to small variations in their present conditions. This unpredictable behavior is called chaos.
Before the 20th century, these unpredictable behaviors were known to be consistent with classical or Newtonian theory, but we now know these theories are incomplete. Quantum theory has been found to account for a much wider range of phenomena, including atomic and smaller phenomena that classical theory got wrong, so quantum physics is thought to underlie all physical processes. Yet it’s not immediately apparent how quantum physical laws allow for chaotic systems’ sensitivity to their initial conditions.
Quantum chaos is the branch of physics that studies the relationship between quantum mechanics and classical chaos. Researchers are taking the conditions that cause chaotic behavior in these simple systems and are studying them on the atomic level. Quantum chaos is being used as a launching point for discovery and to create new models in the exotic, quantum world to further understand the familiar, classical models of physics throughout our universe.
Richard Phillips Feynman was one of the world’s great quantum physicists. He was best known for his research in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of superfluidity of supercooled liquid helium, and in particle physics for which he proposed the parton model. Many of his theories and inventions, such as the Feynman diagrams and microelectromechanical systems (MEMS), have evolved into techniques scientists use today. Feynman was able to think visually and invent problem-solving tools that forever altered the direction of theoretical physics. His extraordinary genius along with his blunt, mischievous, and eccentric personality made him a legend.
Many of Feynman’s brilliant ideas were not readily accepted. In the 1940s, Feynman introduced a graphical interpretation called Feynman diagrams to make sense of complex mathematical equations and visualize interactions among particles. These diagrams offered a way to solve the most complex puzzles of theoretical physics at the time. Yet when he first presented his diagrams at a prestigious computational seminar, attendees took the chalk right out of his hand. Young scientists that adopted the diagrams had to use them in secret. Feynman’s diagrams were gradually accepted and his theory of quantum physics and the Feynman diagrams earned him a share of the 1965 Nobel Prize in Physics. Today, Feynman’s diagrams have continued to evolve and physicists rely on them worldwide.
Each year, representatives of the Department of Energy (DOE) Scientific and Technical Information Program (STIP), led by the Office of Scientific and Technical Information (OSTI), convene for their annual meeting. At this year’s working meeting of STIP representatives, held in April and hosted by Los Alamos National Laboratory, there was something different in the air. Each year there is lively discussion, new contacts are made, and important information is shared, but this year's meeting had a different feel overall. Perhaps it was the record number of participants, perhaps it was the number of first-time participants who were eager to learn and gain insight from strong scientific and technical information (STI) management programs in place at other labs and offices, or perhaps it was the feeling of being part of something groundbreaking as the DOE STIP community works together to implement the Department of Energy Public Access Plan. In reflecting on the April meeting, I have concluded that it was “all of the above.”
Emerging mesoscale science opportunities are among the most promising for future research. The in-between world of the mesoscale connects the microscopic objects (atoms and molecules) and macroscopic assemblies (chemically and structurally complex bulk materials) worlds, giving a complete picture – the emergence of new phenomena, the understanding of behaviors, and the role imperfections play in determining performance. Because of the ever-accelerating advances in modern experimental, theoretical, and computational capabilities, Department of Energy (DOE) researchers are now realizing unprecedented scientific achievements with mesoscale science.
George Em Karniadakis is one of the notable mesoscale researchers who are changing what we know about medicine. Dr. Karniadakis, a joint appointee with Pacific Northwest National Laboratory and Brown University, serves as principal investigator and director of the Collaboratory on Mathematics for Mesoscopic Modeling of Materials (CM4), a major project sponsored by the Applied Mathematics Program within the DOE’s Office of Advanced Scientific Computing Research (ASCR). CM4 focuses on developing rigorous mathematical foundations for understanding and controlling fundamental mechanisms in mesoscale processes to enable scalable synthesis of complex materials.