Physics Today Daily Edition
Washington Post: Both David Cameron, who announced that he will step down as prime minister in October, and leading proponents of the UK's departure from the European Union have called for a delay in beginning the country's formal exit. Cameron has said that he would leave the invocation of Article 50 of the Lisbon Treaty to his successor and that the exit has to be officially approved by Parliament. However, some officials, such as France's finance minister Michel Sapin, have suggested that the UK should begin the process as soon as possible. Angela Merkel says she is against conducting informal negotiations that might give the UK more time, but a foreign policy official indicated that the German chancellor might be more accommodating if the UK seriously reconsiders its exit decision.
Nature: Einstein's general relativity has been used to model the expansion of the early universe, but only in a simplified form. The complexity of the equations requires the assumption that matter was uniformly distributed in the early universe, which likely does not match reality. Even after the development of supercomputers, calculations continued the simplification for models that extended beyond a small region. Now two groups have independently created full-universe simulations that include a non-uniform distribution of matter. One group—led by Eloisa Bentivegna of the University of Catania, Italy, and Marco Bruni of the University of Portsmouth, UK—developed a model to study the formation of large, superdense structures. The model developed by the other group—led by Glenn Starkman of Case Western Reserve University in Cleveland, Ohio—focuses on how the universe expands and how its curvature affects the propagation of light. Both groups' models used numerical-solution techniques that were developed for calculating the warping of spacetime caused by black hole pairs like those that created the recently detected gravitational waves.
New Scientist: On 23 June, NASA announced that it intends to continue using the Hubble Space Telescope through June 2021. Launched in 1990 and last serviced in 2009, Hubble can easily continue working into the 2020s, NASA says. The extension of Hubble means the telescope will still be in use when its successor, the James Webb Space Telescope (JWST), is launched in 2018. Using the two telescopes in tandem will provide a valuable opportunity to study objects with Hubble's visible and UV cameras and JWST's IR cameras.
Nature: Simulations of phenomena involving the strong nuclear force are too hard to perform from first principles on classical computers. Now Esteban Martinez of the University of Innsbruck in Austria and his colleagues have used a quantum computer to complete a proof-of-concept simulation of the conversion of energy into an electron and positron pair. It's the first time a quantum computer has been used to simulate a high-energy physics experiment. The simulation matched the predictions of a simplified form of quantum electrodynamics. The quantum computer contained four qubits in a linear arrangement. Martinez's team now hopes to use a two-dimensional arrangement of qubits and scale up the simulation.
Nature: The Square Kilometre Array (SKA) is an international radio telescope being built in Australia and South Africa. Construction of the first of 197 radio dishes has already begun in South Africa's Northern Cape province, a sparsely populated area of mostly farmland. The SKA project is now facing protests from local residents as the organization begins to purchase more land to construct the majority of the dishes. The SKA organization's initial outreach to the community focused on how the project would create jobs and improve economic and educational opportunities. It currently is providing support for new teachers in nearby Carnarvon and is paying tuition for some students to attend universities. But the benefits have not been evenly distributed among the local communities. Additionally, residents are concerned that the loss of farmland will damage the local economy.
Ars Technica: Over the past several years, the success of the US's Global Forecasting System (GFS) weather model has been challenged by the rise of other models, such as one put out by the European Centre for Medium-Range Weather Forecasts. The competition between models first reached broad popular awareness in 2012, when the European model more accurately predicted the behavior of Hurricane Sandy. In a widely accepted measurement of forecast accuracy, the GFS model has now fallen behind not only the European model but also models from the UK and Canada, based on predictions over the past two months in the Northern Hemisphere. According to Cliff Mass of the University of Washington, the drop in ranking isn't because the GFS model is failing but because the other models have improved significantly.
NPR: The Diablo Canyon Nuclear Power Plant is the last nuclear plant still operating in California. On 21 June Pacific Gas and Electric announced that it would close the plant by 2025 and replace it with renewable energy sources. Diablo Canyon provides energy to 1.7 million homes. Local residents and environmental groups have continually raised safety concerns because the plant and its two nuclear reactors are close to active fault lines. Protests intensified following the earthquake and tsunami that damaged Japan's Fukushima Daiichi Nuclear Power Plant in 2011.
GeekWire: Trevor David of Caltech and his colleagues have spotted an intriguing planet orbiting K2-33, a star in the field of view of the Kepler space telescope during its extended K2 mission. The planet has a diameter about six times that of Earth, and it orbits its star every 5.4 days at a distance of 7.4 million km. Further examination of the system revealed that the star is still surrounded by gas and dust from the protoplanetary disk. The presence of the disk's remnants suggests that the planet is less than 10 million years old, since models of planetary system evolution predict that disks dissipate fairly quickly. Now researchers have to figure out why the youthful planet is so close to its star; most models suggest that large planets form far away and then migrate inward later.