Dimpled surfaces offer a useful and easily implementable way to reduce friction between lubricated surfaces as they slide over each other. Through cutting-edge simulations, Dr. Robert Tomkowski and colleagues at the KTH Royal Institute of Technology in Sweden explore how the microscale structures of surface dimples can be optimized to minimize friction. Their findings could help to reduce wear in mechanical systems, while also making them more energy efficient.

As an inherently brittle material, concrete often needs to be replaced after just a few decades: driving a demand which incurs significant costs for Earth’s climate. Through their research, Professors Suzanne Scarlata and Nima Rahbar at Worcester Polytechnic Institute, Massachusetts, introduce a new mechanism that allows concrete to quickly repair itself, with the help of an enzyme vital to the function of living cells. This approach could help to reduce the world’s insatiable demand for concrete.

In principle, travelling wave reactors offer a safe, highly efficient approach to generating nuclear power. However, development has been held back by a variety of challenges linked to the need for extensively high burn-up in the reactor core, meaning very high rates of generated energy which can damage the reactor. Inspired by the principles of Tai-Chi, a team led by Di Yun from Xi’an Jiaotong University has shown that with the right approach, a high temperature operation, usually deemed as a threat, can be transformed into useful advantages, bringing the practical rollout of travelling wave reactors one step closer to reality.

In 2009, astronomers detected a mysterious source of high-energy, chargeless particles, which appeared to originate from the very edge of the solar system. Through fresh analysis, Dr Li Lu and colleagues at the Chinese Academy of Sciences have discovered that this distance may be an illusion, created by an effect relating to the solar wind as viewed by the commonly used parallax method. If correct, the team’s theory suggests that the as-yet enigmatic signal could actually originate from a source just beyond Earth’s atmosphere.

Outdoor swimming pools are enjoyed by millions of us, but it is often challenging to maintain comfortable temperatures across different climates and weather conditions, which can drastically vary the rate of heat transfer away from the water. Through their research, a team led by Prof. Hui Tong Chua from The University of Western Australia has introduced a new empirical model that can accurately predict this transfer of heat, accounting for weather conditions and the surrounding environment. They hope that their model could improve the efficiency of outdoor pool heating systems, helping them to become more sustainable.

Astronomers know that the nearby Centaurus A galaxy contains a supermassive black hole at its centre, but there are several unusual and mind-boggling features in the detailed picture that was recently made of this galaxy’s core, which have yet to be explained. To understand these anomalies, Dr David Anthony Cosandey, an astrophysicist at the Zurich Higher Education Centre, suggests that the galaxy actually contains a pair of supermassive black holes which will eventually merge into a single object. If his theory is confirmed, Centaurus A could not only host the tightest orbiting pair of these immense objects ever discovered; this pair of giant black holes would also be by far the nearest to us that we know of.

Studying single molecules provides researchers with unique insights into biological mechanisms and processes and allows them to visualise microscopic structural and functional differences. However, results can be unpredictable, and investigations are labour-intensive and expensive, often requiring extensive training and highly specialised laboratory equipment. Dr Rishabh Shetty and colleagues at Arizona State University, the California Institute of Technology, and the Massachusetts Institute of Technology, USA, have recently developed a simplified single-molecule assessment technique to overcome these limitations with a view to increasing accessibility and precision in molecular-level research.

In the world of chemistry, solvate-assisted grinding is a new method that could revolutionize how we make important chemical compounds. Researchers Henry DeGroot and Dr. Timothy Hanusa at Vanderbilt University have developed this technique, which uses mechanical energy instead of traditional liquids. This not only makes the process more efficient, but also reduces pollution. It could lead to better medicines, advanced materials, and cleaner chemical production methods.

Satellites are vital to modern civilization, powering the GPS in our phones, enabling long-range communication, and giving us insights into Earth’s climate and the universe beyond. We now launch thousands of new satellites into space each year, dramatically increasing the risk of collisions. Such satellite collisions create debris that can damage more satellites. Thomas Kleinig and his colleagues are developing and testing a new approach to avoid collisions by exploiting a unique property of the thin atmosphere that satellites travel through.

To understand how the smallest known particles in our universe form structures, scientists need to use sophisticated mathematical models and techniques. These help scientists to estimate the energies of these particles, to work out how they combine and interact. In a recent paper, Dr Eef Van Beveren from the Centre for Physics of the University of Coimbra and Dr George Rupp from the Centre of Physics and Engineering of Advanced Materials of the University of Lisbon review the techniques that have led to scientific discoveries about mesons – subatomic particles that exist for tiny fractions of a second. They also discuss how such techniques may evolve into the future.