Physics Today Daily Edition
New York Times: The National Oceanic and Atmospheric Administration has joined NASA and the Japan Meteorological Agency in reporting that each of the first three months of 2016 saw record-high temperatures that surpassed the previous records set during those months in 2015. March was also the 11th straight month to set a new monthly record. The warming has been tied to an extremely strong El Niño combined with the effects of climate change. The report from NOAA comes as the nations that agreed to the Paris climate agreement last year are meeting to formally sign the pact.
Space.com: Since 2004, NASA's Cassini spacecraft has been sampling dust as it orbits Saturn. The vast majority of the dust particles have come from eruptions from Saturn's moon Enceladus, but 36 of the particles have been traced to the interstellar medium. The interstellar dust is believed to have come from the local interstellar cloud—the region of dust and gas that the Milky Way is currently moving through. The interstellar particles stand out from the local dust particles because of their direction and high speed. Both NASA's Galileo and the joint NASA–European Space Agency probe Ulysses have detected interstellar dust before, but Cassini was the first probe able to provide measurements of the concentrations of rock-forming elements in the dust. Although the concentrations matched what was expected, the particles were surprisingly uniform in composition. That uniformity may arise from the dust being destroyed and reformed repeatedly by supernova shock waves.
New Scientist: Yesterday at the American Physical Society meeting in Salt Lake City, Utah, researchers from the High-Altitude Water Cherenkov Observatory (HAWC) revealed their first map of the universe's gamma-ray signals. HAWC, which is located on a mountain in central Mexico, consists of 300 tanks, each filled with 200 000 L of purified water. They are used to detect the cascade of particles created when high-energy photons strike the atmosphere. As the particles pass through the tanks, they emit visible Cherenkov radiation, which the researchers use to calculate the particles' source. In the first year of data collection, HAWC identified 40 distinct gamma-ray sources, 10 of which had not previously been detected. The researchers are now trying to determine if those sources can be matched with known emitters at other wavelengths.
CBC News: On 15 April, Canadian prime minister Justin Trudeau affirmed the country's 2016 budget allocation of Can$50 million over the next five years for the Perimeter Institute for Theoretical Physics in Waterloo, Ontario. An independent think tank established by entrepreneur Mike Lazaridis in 1999, the Perimeter Institute provides not just high-level theoretical research but also educational outreach and a popular series of lectures on physics. The Canadian government began including funding for the institute in its budget several years ago to help promote that research and education. While answering questions from the press, Trudeau impressed and surprised both the media and the researchers in attendance with his ability to give a clear explanation of the significance of the institute's research into quantum computing.
New York Times: China, Russia, and the US are all actively working to develop a new generation of nuclear weapons that are smaller and more precise than previous devices. And because of each country's modernization efforts, no progress has been made on new arms-control treaties. In the US, the next generation of weapons is intended to reinforce nuclear deterrence by replacing older weapons with updated versions. That program, estimated to cost $1 trillion over 30 years, is prompting China and Russia to not just modernize weapons but also develop new types of warfare. For example, Russian news reports say that the country's navy is developing a drone that can spread radioactive contamination over a wide area. Independent analysts worry that Russia would be willing to violate the Comprehensive Nuclear-Test-Ban Treaty as part of its development process. And China is developing a hypersonic missile similar to one that the US has tested unsuccessfully. Analysts are particularly worried that all those efforts may increase the likelihood that nuclear weapons are used in a local conflict and that they weaken the concept of mutual assured destruction that has served to deter the use of nuclear weapons since the 1950s.