Thanks to increasingly cheap, fast and efficient computing power, scientific simulations are now a crucial tool for researchers who want to ask once impractical scientific questions or generate data that laboratory experiments can’t. But there's more to harnessing an army of computers than testing a hypothesis or extrapolating real-world observations. Simulations contextualize and clarify mountains of data into striking graphics that play to human strengths. "The human eye can pick out patterns in simulations that are are otherwise hard to describe, and they can do it better than any computer," said visualization scientist Joseph Insley of Argonne National Laboratory. "Plus, with the incredible amount of data gathered these days, it's difficult to analyze it any other way." Making a useful scientific simulation isn't light work. If field researchers want to do it themselves, they must learn to code instructions for computer processing and control advanced 3-D animation software. Because of these hurdles, and the increasing sophistication of modeling methods, most team up with computer and visualization scientists to get the job done. Ready-to-run simulation instructions can demand incredible computing resources. To churn out timely and useful data, it's not unusual to consume millions of processor hours. (Thirty minutes of nonstop number-crunching on a personal computer's dual-core processor, for example, is equivalent to one processor hour). To reward the past year's most impressive scientific simulation efforts with bragging rights — and a shiny, Oscar-like statue — Insley and others coordinated the fourth "Visualization Night" competition. The U.S. Department of Energy hosted the event in July 2011 during its annual program called SciDAC, or Scientific Discovery through Advanced Computing. Twenty-three hopefuls entered, but only 10 earned a "people's choice" award from their scientific peers. Two won awards from a three-person panel of experts. We review the researchers' favorite animated submissions in this gallery. Above: Blood Flow To explore microscopic interactions between healthy blood cells (red) and sickly ones (blue), researchers created the above simulation using everything from fluid physics to particle dynamics. Blood cells and plasma particles (small spheres) gush through a simulated artery in the first leg of this animation. Multicolored slices through the artery reveal the velocities of blood components. A second simulation captures how blood-clotting platelet cells cram into a potentially lethal aneurysm, or weakened cell wall that bulges outward. Simulation: L. Grinberg, G. Karniadakis, D. Fedosov, B. Caswell, J.A. Insley, M.E. Papka/Brown University/ANL

Magnitude-8 Earthquake Seismologists keep a close eye on faults in the Earth’s crust with extensive sensor arrays, yet massive ruptures are too infrequent to understand well. To probe the behavior of big quakes along the San Andreas fault, visualization scientist Amit Chourasia of the San Diego Supercomputing Center and his colleagues created a “worst-case scenario” magnitude-8 earthquake model. The simulation, which took 5.3 million processor hours to compute, condenses about four minutes of time after a fault ruptures near Bombay Beach. Most of the energy ripples southward, but unlike in previous earthquake simulations, the team displayed the sporadic movement of simulated pieces of the ground with an exaggerated height. “Some of these simulations helped scientists see persistent motion in some regions, like L.A. It just hangs out there,” Chourasia said. The simulations also revealed a conical front of energy reminiscent of the Mach cones jet fighters make when zooming beyond the speed of sound. “In previous simulations, we didn’t see any Mach cones,” Chourasia said. “We don’t know if these actually occur in the real world, since this is a simulation, but we have a very good idea of what they look like if they do.” Simulation: A. Chourasia, Y. Cui, K. Olsen, T. Jordan, K. Lee, J. Zhou, P. Small, D. Roten, G. Ely, D. Panda, J. Levesque, S. Day, P. Maechling/SDSC/SDSU/USC/OSU/Cray, Inc./ORNL/NSF

Stellar Magnetism Astrophysicists know solar magnetism drives the formation of sunspots — surface disturbances able to launch dangerous clouds of particles into space — but how the blotches are built and organized isn't entirely clear. "Our recent predictions failed to predict activity in this solar cycle," said astrophysicist Benjamin Brown of the University of Wisconsin, Madison. Instead of a lot of activity, the most recent 11-year-long solar cycle was eerily quiet. Brown and others are modeling the convoluted magnetic fields in sun-like stars to understand why. In particular, they want to know how stellar magnetism simultaneously responds to and drives the flow of hot gases near a star's surface. One surprise is they've discovered wreath-like structures that may foreshadow a sunspot's emergence. "These wreaths are new, but unfortunately any sunspots would be right at or below the resolution of our model," Brown said. "It's conceivable to do a much larger simulation and see if these structures pop out at the surface." The animation above approximates roughly five years' worth of magnetic fluctuations. It is a subset of a 75-year-long simulation that took between 4 and 8 million processor hours to compute. Simulation: C. Brownlee, B. Brown, J. Clyne, C. Touati/NSF/NCAR/SCI Institute, University of Utah

Active Galactic Nuclei Magnetism Churning at the heart of roughly one in few thousand galaxies is a supermassive black hole that gobbles matter from a spinning disk of gas and dust. Astronomers call the most energetic of these objects active galactic nuclei, or AGNs, after the powerful jets of radiation they spew. In addition to radiation, AGNs accelerate charged particles that, in turn, generate a magnetic field. Although that magnetism is extremely weak, the simulation above suggests they're important in shaping the visible universe. "It's somewhat of a puzzle why the field lines are so weak" and where they come from, said astrophysicist Paul Sutter of the University of Illinois, who worked with computer and visualization scientists on the simulation. "But they may play a significant role in affecting galaxy cluster physics." This model shows an AGN’s magnetic field lines about 6 billion years after the Big Bang, and it occurs in a cube roughly as big as a cluster of galaxies. The competition’s jury awarded it as the best in the “visual aesthetics” category. Simulation: P.M. Sutter, P.M. Ricker, H.-Y. Yang, G. Foreman, D. Pugmire/ORNL

Supernova Shockwave Magnetism Stars and active galactic nuclei aren't the only celestial objects that generate hard-to-observe magnetism. Some massive stars die as fiery supernovas, and astrophysicists think the explosion's outward-racing shockfront of particles can create magnetic fields — a force that might strongly guide how remnants look eons after a star's explosive death knell. To estimate what that magnetism would look like and how it would influence the rush of material behind the shockfront, computer scientist David Pugmire of Oak Ridge National Laboratory and a team of astrophysicists created this simulation. While not as complex as other Visualization Night winners, its simplicity is revealing. The simulation freezes a supernova in time just moments after it begins and reveals how magnetic field lines wind-down to a central, 25-mile-wideneutron star (which is all that remains of most supernovas). Simulation: E. Endeve, C. Cardall, R. Budiardja, A. Mezzacappa, D. Pugmire/ORNL

Laser-Plasma Accelerator Particle accelerators smash bits of matter at near light-speed, all in an effort to recreate stuff that existed shortly after the Big Bang. Trouble is, the machines require a lot of room and cash to build. Europe's 17-mile-around Large Hadron Collider, for example, has a budget of about $9 billion. "They're getting way too big and expensive, so we're trying to develop new technologies to reduce their size and cost," said computer scientist Estelle Cormier-Michel of the Tech-X Corporation. "One idea is to shoot plasma with big lasers." Called laser-plasma acceleration, the infant technology blasts a laser through ionized plasma to generate an electrified "wake." A second laser blast collides with the first, popping electrons out of the plasma. The electrons then hitch a ride on the wake and accelerate toward the speed of light, all in about a meter of space (these electrons would ultimately collide with electrons made with an identical machine pointing the opposite direction). Cormier-Michel, who works on simulations like the one above, said computer models help experimental physicists see how tweaking costly prototypes might help or hinder electron acceleration. To replace gargantuan accelerators, that acceleration needs to be extremely stable and reproducible. "If I'm a physicist, I want the beam to have this energy and this charge and be the same every shot. That's not the case right now with this technology," she said. "We have a ways to go, but the simulations certainly help." Simulation: E. Cormier-Michel, D.L. Bruhwiler, M. Durant, D. Kindig, V.H. Ranjbar, B.M. Cowan, J.R. Cary C.G.R. Geddes, M. Chen, O. Ruebel/LBNL/Tech-X Corp.

Early Galaxy Radiation Researchers suspect the universe expanded from a hot, dense point into the present-day universe over a 13.75-billion-year period. Knowing exactly what happened in between is tough to say, but computer models can make useful predictions. One riddle cosmologists are trying to resolve with simulations is to what extent gravity, fluid-like dynamics and light from young stars shaped the present cosmos. The above, cube-like simulations are the same snapshots in time of the universe as it may have appeared 1.9 billion years ago. Edges of the cubes are each roughly 36 million light-years wide, and all contain filamentous clusters of galaxies. The top-left simulation models the density and gravitational interactions of visible matter, and the top right models the hydrodynamics of dark matter (unseen particles which make up 83 percent of all matter in the universe). The bottom left cube simulates the light output of primordial, metal-free stars while the bottom-right cube shows how that light might be absorbed and re-emitted by surrounding gas and dust. All of the simulations took about 2 million processor hours to generate. They're so intricate that, even months after their creation, physicists are still digging through the data to see what they've got. "Once we're done, some day we'd like to add a fourth player called magnetism to the simulations," said astrophysicist Richard Wagner of the San Diego Supercomputing Center. Simulation: R. Harkness, D.R. Reynolds, M.L. Normal, R. Wagner, M. Hereld, J.A. Insley, E.C. Olson, M.E. Papka, V. Vishwanath/SDSC/Southern Methodist Univ./Univ. of Chicago/ANL

Carbon-Capturing Turbines Computer models can help researchers emulate their experimental results and quantify the forces at work — and then push them to the extremes. A telling example is this simulation of a turbine-powered technology designed to capture carbon dioxide gas generated by fossil fuel-burning industries. Designed by Ramgen Power Systems, the process relies on supersonic speeds to apply shock compression to turn carbon dioxide gas into a fluid for easier storage. The simulation above closely matches Ramgen's real-world experiments in wind tunnels, allowing their engineers to more quickly improve prototypes. "It provides insight that cannot be gained without visualization," wrote visualization scientist Michael Matheson of Oak Ridge National Laboratory, who helped Ramgen design their simulation, in an e-mail to Wired. The visualization is part of a larger set that took about 2 million processor hours to compute, and it won best of the "information presentation" category. Simulation: M. Matheson, A. Grosvenor, A.A. Zheltoyodoy/Ramgen Power Systems/Khristianovich Insitute/ORNL

Overhead Threat Protection System When troops set up camp in areas of conflict, they face the threat of incoming mortar shells. It's an explosive attack that a simple roof can’t thwart. Enter the U.S. military's "overhead coverage system," which could be set up in a matter of hours. Don't let the boring name fool you. A simulated prototype (above) shows how explosive energy might be directed away from troops with a two-layer design. "The Army Corps of Engineers wants a rapidly deployable overhead structure to protect things like a mess hall on the front lines. These are unarmored and easy targets," said computer scientist Randall Hand of the Department of Defense, who helped create the simulation. An outer layer made of corrugated metal detonates explosives while an inner layer protects structures and guides blast energy out of the roof's open sides. The simulation hints that the design is sturdy enough to withstand a modest blast, but the inner layer is top-secret technology. "I don’t even know what it's made of," Hand said. Simulation: C. Price, J.A. Sherburn, D. Nelson, J. McCleave, M. Stephens, R. Hand, K. George, and Mi. Valenciano/DoD