Flash Physics is our daily pick of the latest need-to-know developments from the global physics community selected by Physics World's team of editors and reporters
Synchrotron may help with giant-dinosaur mystery
Synchrotron X-ray analysis may provide the answer to how dinosaurs became giants. A collection of dinosaurs specimens, ranging from eggs to juveniles, has been analysed at the European Synchrotron Radiation Facility (ESRF) in France. It is the first time such a range of ages of the same species has been studied at ESRF and it could provide answers about dinosaur growth and evolution. Found in a reproductive colony in central Patagonia, the specimens analysed are prosauropod Mussaurus patagonicus – a primitive herbivorous dinosaur that lived 200 million years ago during the Late Triassic period. Prosauropods are believed to be ancestors of the giant sauropod dinosaurs common to the Jurassic period. However, how they evolved from intermediate-sized creatures to massive giants remains a mystery. Now, palaeontologist Diego Pol from the National Scientific and Technical Research Council (CONICET) in the Museum of Palaeontology Egidio Feruglio in Argentina hopes that high-resolution X-ray analysis will provide some answers. The study involves 30 eggs, a baby and a juvenile Mussaurus patagonicus. After being unable to achieve sufficient data in the home laboratory, Pol turned to Vincent Fernandez of ESRF. The synchrotron has been performing palaeontology studies for around a decade. By using high-energy X-ray radiation, 3D anatomical models can be built without the need to damage specimens. Furthermore, high-resolution investigation means it is possible to analyse the bone-growth patterns of the dinosaurs. While the data collected remain to be fully processed, it could provide key answers to Mussaurus patagonicus growth and the origin of giant dinosaurs.
Coffee-ring effect could make better solar cells
A chance observation that a semiconductor solution behaves like spilled coffee could result in better electronic devices, according to researchers at the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia. When coffee dries on a surface, the coffee solids are pushed towards the edge of the puddle to create a familiar coffee ring. This effect occurs in many liquids that contain tiny particles, and now Aram Amassian, Liyang Yu and colleagues have harnessed it to improve how thin-film semiconductors form when they are deposited in solution on a non-crystalline substrate. These semiconductors normally form polycrystalline films of tiny crystallites that are randomly oriented. While this is fine for some electronic devices, performance could be boosted by gaining more control over the crystal structure. Yu noticed that an organic semiconductor solution formed a coffee ring as it crystallized. Oddly, the thickest parts of the ring crystallized first, which is the opposite of what was expected. This led Yu to discover that the depth of the solution had an important effect on how the crystals were forming. Using this insight, the team used the local thickness of the semiconductor solution to create patterned semiconductor films in which the locations and orientations of crystallites can be controlled. “We can now make customized polycrystals on demand,” explains Amassian. The team hopes its discovery will lead to improvements in a wide range of devices including solar cells, and they describe the research in Science Advances.
AAAS’s Rush Holt responds to new Trump travel ban
“We are concerned that the executive order announced 6 March may be implemented in a manner that will continue to restrict travel to the US and negatively impact students and scientists who seek to work and collaborate with their peers in the US,” says physicist Rush Holt, who is chief executive of the American Association for the Advancement of Science (AAAS). Holt was responding to a new executive order from US president Donald Trump that limits travel from six Muslim-majority countries in the Middle East and Africa. “Scientific progress depends on openness, transparency, and the free flow of ideas; these principles have helped the US attract and benefit from international scientific talent,” adds Holt. “Impacts to US leadership in science, technology and innovation should be considered in development of immigration and visa policy.”
Cash boost for South African radio telescope
The Hydrogen Epoch of Reionization Array (HERA) observatory, located in Losberg near Carnarvon in South Africa, has received $5.8m from the Gordon and Betty Moore Foundation in the US. The telescope array is currently under construction and consists of 35 14 m radio dishes. Last year, the US National Science Foundation announced it would invest $9.5m in HERA to boost the number of dishes to 240 by 2018. The new money from the Gordon and Betty Moore Foundation will increase that number even further to 350. The rise in the number of dishes will allow astronomers to explore the large-scale structures that formed during and prior to the epoch of reionization – a billion-year period after hydrogen collapsed into the first galaxies, a few hundred million years after the Big Bang. HERA is a precursor array to the upcoming Square Kilometre Array that will be built in southern Africa and Australasia in the coming decade.