Cern Courier

In March 1989, Tim Berners-Lee, while working at CERN, released his proposal for a new information-management system. Within two years, the web was born. CERN’s subsequent agreement in 1993 to place the underlying software in the public domain (reproduced in this issue) shapes the web’s character to this day.

When CERN was just five years old, and the Proton Synchrotron was preparing for beams, Director-General Cornelis Bakker founded a new periodical to inform staff what was going on. It was eight-pages long with a print run of 1000, but already a section called “Other people’s atoms” carried news from other labs and regions. Sixty years and almost 600 Couriers later, high-energy physicists are plotting a new path into the unknown, with the update of the European Strategy bringing into focus how much traditional thinking is shifting, with new ideas and strong opinions in abundance.

Cosmic rays, being relatively easy to detect using inexpensive equipment, offer an ideal outreach and educational tool. Two projects described in this issue – Polarquest2018 and Clean2Antartica, which stem from existing networks of cosmic-ray detectors installed on high-school rooftops in Italy and the Netherlands – are taking cosmic-ray experiments to polar latitudes for the benefit of science, education and the environment.

Particle physics rarely stands still, and the articles in this issue offer a snapshot of activities under way at CERN and elsewhere to secure the field into the next decade and beyond. Chief among these are the upgrades to the LHC experiments..

Explaining the strong interaction was one of the great challenges facing theoretical physicists in the 1960s. Though the correct solution, quantum chromodynamics, would not turn up until early the next decade, previous attempts had at least two major unintended consequences.

Of all the particle colliders that have been built over the past half-century or so, one type stands out for its rarity: the electron–hadron collider. The only machine so far in this class is the 6.3 km-circumference electron–proton collider HERA, which operated at DESY in Germany between 1992 and 2007.

It is 100 years since Ernest Rutherford published his results proving the existence of the proton. For many decades the proton was considered elementary. But ever since experiments at SLAC and DESY started firing electrons into protons, beginning in the 1960s, deep-inelastic-scattering experiments have revealed a complex internal picture.