Physics Today Daily Edition
Science News: In 2009, a star 19 million light-years away increased in brightness over the span of several months, eventually reaching a luminosity 1 million times that of the Sun. The star appeared to be going supernova. But instead of progressing to a tremendous explosion, the star suddenly disappeared. Thinking that the star had perhaps been hidden by a cloud of dust, Scott Adams of Caltech and his colleagues used the Hubble Space Telescope to examine the region of sky. Where the star had been, they found a faint IR signature, which they believe is evidence of material falling into a black hole that formed via the star's collapse. If the interpretation is correct, then this is the first star known to have become a black hole without first going supernova. Such a process has been described in theories that say some stars are so massive that the supernova process cannot overcome the stars' own gravity. If the star did become a black hole, the debris falling in is likely emitting x rays. Adams's team is awaiting observations from the Chandra X-Ray Observatory.
Reuters: On 18 September Canadian environment minister Catherine McKenna announced that the government would put a price on carbon emissions from any of the country's provinces that do not adequately regulate emissions themselves. The policy will go into effect in October, McKenna said. She did not provide details about how the price would be set, what efforts the provinces are expected to make, or how the government would enforce the payments or penalties. She also did not address whether the current government would be altering the previous government's pledge to cut emissions to 30% below 2005 levels by 2030, a target that is likely unreachable without significant efforts by both the national and provincial governments.
Guardian: A common claim from those disputing the hazards of anthropogenic climate change is that rising carbon dioxide levels have led to increased global plant growth. There is some evidence supporting that claim. However, a new paper suggests that now that the global CO2 concentration has surpassed 400 ppm, the detrimental effects of rising temperatures will outweigh the benefits of further CO2 increases. Between 1998 and 2014, researchers at Stanford University grew 132 plots of common California flowers and grasses and varied the temperature, water, and CO2 and nitrogen levels. The results showed that plant growth increased with higher concentrations of nitrogen and decreased with rising temperatures. But beyond current global atmospheric levels, CO2 had no notable effect on plant growth.
Ars Technica: Light moves too quickly for computer chips to process it. By the time a chip has determined how to route data encoded in light, the pulse has already passed by. To prevent signal loss, chips divert the light pulses and store data electronically, but that is a slow and inefficient process. Now a team of Australian researchers has developed a way to briefly slow down the light: They convert the light pulses into sound pulses and then back again. The technique isn't new—it's commonly used in lasers—but adapting the idea for data transmission required finding a way to create and propagate the sound waves with minimal data loss. The researchers converted a standard light pulse and then collected the signal with the full data load 3.5 ns later, which is a significant slowdown in transmission that doesn't require storing the data electronically.
Washington Post: In May 2016, Arctic sea ice levels were lower than they were at the same time in 2012, which is the year levels dropped to the lowest minimum coverage ever recorded. That finding did not bode well for Arctic ice levels this year. However, increased cloud cover over the summer appears to have had a cooling effect on the region, as preliminary measurements of the minimum level for 2016 show it is only the second lowest ever recorded. The 2016 minimum, reached on 10 September, was 4.1 million km2 (1.6 million mi2).
BBC: The UK government has approved an £18 billion ($24 billion) project to construct a nuclear power plant at Hinkley Point in Somerset, England. The project is being financed by the French and Chinese governments. As part of the agreement, the UK can prevent EDF, France's state-controlled energy firm, from selling its stake in the project. EDF is providing two-thirds of the funding for the project, which is expected to create more than 25 000 jobs. The Chinese investment also included an agreement for the development of a new nuclear plant at Sizewell in Suffolk and an understanding that the UK would approve another Chinese-led project at Bradwell in Essex. The 3.2 GW Hinkley Point power plant will satisfy roughly 7% of the UK's energy needs.