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Each year millions of patients benefit from diagnostic services enabled by advances in medical imaging. However, some services rely on the supply of technetium-99m from an ageing nuclear infrastructure. Kevin Charlton discusses new technologies to secure a sustainable supply.

Jose R. Alonso and colleagues describe technical advances that will allow the proposed IsoDAR (isotope decay at rest) cyclotron — being developed for neutrino physics research — to produce many medical isotopes more efficiently than existing cyclotrons can.

In positron emission tomography, up to 40% of positron annihilation occurs through the production of positronium atoms in the patient’s body, whose decay could provide information about disease progression. New research is needed to take full advantage of this information.

Despite much effort, the question of whether the Navier–Stokes equations allow solutions that develop singularities in finite time remains unresolved. Terence Tao discusses the problem, and possible routes to a solution.

Data show that apart from their prize-winning work, the careers of Nobel laureates follow the same patterns as those of the majority of scientists.

Oliver Brüning and Lucio Rossi discuss an upgrade of the Large Hadron Collider (LHC), the High-Luminosity LHC (HL-LHC), which aims to significantly increase the luminosity.

Steinar Stapnes discusses the Compact Linear Collider, a linear accelerator that could be built in three stages at CERN.

Edda Gschwendtner and Patric Muggli discuss the concept of plasma wakefield acceleration and its potential for future particle colliders and other applications.

XinChou Lou describes the plans for the Circular Electron Positron Collider, a large accelerator complex that would be built in China.

Michael Benedikt and Frank Zimmermann describe the Future Circular Collider, a proposed collider-based research infrastructure that can be realized in successive steps.

Shinichiro Michizono describes the International Linear Collider, a proposed 250 GeV electron–positron collider using superconducting radiofrequency technology.

Paul Howarth discusses the current challenges and opportunities in nuclear research and development.

Many small research reactors used as neutron sources are being shut down. To replace them, new facilities are being developed. In particular, compact accelerator-based neutron sources can take up many of the activities previously supported by reactor-based facilities.

Gail Marcus discusses the current social, political and economic factors shaping the development of nuclear power worldwide.

Physics keeps changing and so do classification and subject indexing. Arthur Smith recalls the final updates to the Physics and Astronomy Classification Scheme (PACS) and the development of the Physics Subject Headings (PhySH), and ponders future directions.

Modern theoretical physics is indivisible. Ideas flow freely and fruitfully across traditional boundaries separating materials physics, fundamental physics and cosmology. How did this state of affairs come to be? What are its outstanding results? Is there more to come? Frank Wilczek discusses the synergy between the different fields of physics.

The review article has a rich history and Roberto Lalli tells the story of how this scientific genre evolved in physics.