Physics Today’s online staff summarize the most important and interesting news about science from the world's top media outlets.
Science: Two teams of researchers have developed separate mechanisms that allow microscopic particles to move against the flow of liquid. The first team, from New York University, used a micrometer-sized plastic sphere with an exposed area of iron oxide. When placed in a hydrogen peroxide solution and activated by blue wavelengths of light, the iron oxide splits oxygen away from the hydrogen peroxide molecules. The resulting electrical gradient is strong enough to push the microparticles against the flow of the solution in a small capillary. The second team, from the University of California, San Diego, used a similar chemical reaction to increase the catalytic effect of an effort to produce hydrogen gas for fuel cells. In a solution of sodium borohydride, platinum reacts strongly, producing hydrogen gas. However, the platinum molecules are quickly covered in hydrogen bubbles, which slow then stop the reaction. So the researchers created a two-piece microparticle, half platinum and half titanium. Because the bubbles are produced on only half of the microparticle, the ejection of hydrogen gas from that side pushes the microparticle away, and the reaction can continue. The resulting process is 20 times more effective than simply reacting platinum with sodium borohydride.
Nature: Real-time data from the 24 April eruption of the underwater Axial volcano were captured by a range of instruments in place off the Oregon coastline. The instrumentation, which included seismometers, pressure and temperature sensors, and a mass spectrometer, was put in place as part of the $386 million Ocean Observatories Initiative (OOI). The seismometers picked up a spike in activity on 23 April, which gave the OOI researchers time to prepare for the eruption. Unfortunately, the systems designed to provide full data to researchers outside of the initiative's monitoring organization were scheduled for completion in the next three months. The raw seismic data were live streamed outside of the OOI, but the rest of the data were recorded and will be provided in the next several days.