Criminals tempted to return to the scene of the crime might find themselves rethinking that impulse if the Questionable Observer Detector is embraced by police forces. The QuOD scans video of a crime scene, searching for those in all-too-frequent attendance, hoping that those repeat gawkers might in fact know something about the crime itself.
Tiny bacteria may seem rather unintelligent, but a bacterial crowd can accomplish the Sisyphean task of turning microgears millions of times bigger than themselves. The microbes start out by swimming randomly, but occasionally collide with the spokes of a gear and begin pushing. Scientists from the U.S. Department of Energy's (DOE) Argonne National Laboratory and Northwestern University observed a crowd gather and push against the spokes.