Physics Today Daily Edition
MIT Technology Review: The Joint Center for Artificial Photosynthesis (JCAP) was established by the Department of Energy in 2010 as one of the agency's Innovation Hubs. Now the center's researchers have demonstrated a device that uses solar energy to electrolyze water. Electrolysis produces hydrogen gas, which can be stored and used to generate electricity. With conventional electrolysis, it costs between $10 and $20 to produce the amount of hydrogen fuel equivalent to one gallon of gasoline. Solar electrolysis could reduce that cost to $2–4, according to JCAP director Nathan Lewis. The system that JCAP developed combines electrolysis catalysts with solar cells to produce a less complex system of electrodes that have a lifetime of 1000 hours. Although that is not long enough for commercial devices, it shows significant progress. However, the $122 million originally provided to JCAP will run out later this year unless Congress provides more funding.
Miami Herald: In 2011, Governor Rick Scott took office in Florida and appointed Herschel Vinyard Jr as the director of the state’s Department of Environmental Protection (DEP). According to many DEP employees, shortly thereafter they were instructed to stop using phrases such as “climate change” and “global warming” in official documents and statements. However, both Tiffany Cowie, the DEP’s press secretary, and Jeri Bustamante, Scott’s spokeswoman, have denied that any such policy was ever put in place. Scott has previously said that he was not convinced by the evidence for climate change and also that he is “not a scientist.” Florida is under severe threat from the effects of climate change; up to 30% of its beaches are predicted to be submerged by the end of the century as sea levels rise.
Guardian: A team of researchers led by Geronimo Villanueva of NASA's Goddard Space Flight Center in Greenbelt, Maryland, reports that Mars used to have an ocean that held more than 20 million km3 of water. The team used several IR telescopes to study the Martian atmosphere for six years; they looked specifically at seasonal and regional changes in water molecules. Normal water molecules in the atmosphere are able to escape Mars's gravitational pull, but heavy water molecules, in which one or both hydrogen atoms have been replaced by deuterium, are not. Consequently, the concentration of deuterium in the planet's atmosphere and in ice can be used to infer historical water levels on the planet's surface. According to the researchers' calculations, if Mars were smooth, it would have been inundated to a depth of 137 m. Given its terrain, however, the researchers suggest that the water pooled into an ocean that covered 20% of the planet's surface. As Mars lost its atmosphere, much of its water vaporized and was then lost to space. The remaining water, which is frozen in the polar ice caps, is only 13% of the volume of the ancient ocean.
Ars Technica: A comparison of historical climate data from California with different climate models has shown the influence of human-driven climate change. Noah Diffenbaugh, Daniel Swain, and Danielle Touma of Stanford University examined the state's records of temperature, rainfall, and drought conditions and evaluated the severity of different periods of warming and drought using the Palmer Hydrological Drought Index and the Palmer Drought Severity Index. They then compared those periods with a range of global climate models. The models that included only naturally occurring variations did not accurately depict California's warm periods, but the models that included anthropogenic warming did. The researchers believe that anthropogenic warming has increased the simultaneous occurrence of periods of both warming and decreased rainfall, which has resulted in an increase in the frequency and severity of droughts across the state.
Sydney Morning Herald: A budget fight in Australia's federal government threatens the funding for a number of the nation's research institutes. According to a letter written by the National Research Alliance to Prime Minister Tony Abbott, many of the National Collaborative Research Infrastructure Strategy's 27 agencies will be forced to shut down if their funding is delayed. The facilities require just $150 million in annual operating costs, but that money supports more than $2 billion worth of infrastructure and equipment.
Los Angeles Times: Gravitational lensing has revealed a galaxy that, despite being just 700 million years old, has a dust-to-gas ratio similar to that of the Milky Way, which is 13 billion years old. Darach Watson of the University of Copenhagen and his colleagues were able to examine the distant galaxy because its light gets amplified by passing through a massive galaxy cluster called Abell 1689. Galaxies that formed early in the universe's history had not been expected to have collected much dust because most early dust would have been reused to form new stars.