Particle Physics Symposium Examines Past to Shape Future Directions

The 4th International Symposium on the History of Particle Physics took place at CERN in November, where experts gathered to reflect on the past and explore the future challenges facing the field. The symposium, hosted in CERN’s historic auditorium, attracted attention for its focus on the less-discussed aspects of scientific progress, such as funding issues and experimental failures. According to Chris Llewellyn Smith, a former director-general of CERN, participants were encouraged to share insights about “what’s not written in the journals,” emphasizing the importance of understanding the complexities surrounding scientific discovery.

The gathering highlighted a transformative period in particle physics during the 1980s and 1990s. Significant advancements were made, including the operation of major accelerators like the Large Electron-Positron Collider (LEP), which began in 1989, and the approval of the Large Hadron Collider (LHC) five years later. Delegates also discussed the historic UA1 and UA2 experiments at CERN, where the W and Z bosons were discovered, alongside the groundbreaking Tevatron at Fermilab that commenced operations in 1983.

A notable aspect of the symposium was the examination of projects that did not come to fruition. The cancellation of the ISABELLE and the Superconducting Super Collider (SSC) highlighted the political and financial obstacles faced by researchers. Meanwhile, discussions on the solar-neutrino problem illuminated the scientific community’s resilience, culminating in the 1998 discovery of neutrino oscillation by Takaaki Kajita, for which he later received the Nobel Prize in Physics in 2015.

In addition to celebrating successful projects, the conference acknowledged the challenges faced by researchers. Some speakers candidly described their endeavors as “failures,” a sentiment echoed by Helen Quinn, who preferred the phrase “falling forward” to illustrate the iterative nature of scientific exploration. Barry Barish, a Nobel laureate, underscored this perspective by discussing his work on gravitational waves and the informal motivations that drove him through his research journey.

The symposium also addressed the broader societal impacts of particle physics. Two speakers recounted the invention of the World Wide Web at CERN in the late 1980s, a development that fundamentally changed global communication and information sharing. The interplay between international politics and science was a recurring theme, with discussions on how high-level negotiations enabled collaborations across borders. For instance, Agnieszka Zalewska elaborated on Poland’s path to joining CERN, while Vladimir Shiltsev discussed the dispersion of Russian physicists following the dissolution of the Soviet Union.

While the conference celebrated past achievements, it also reflected on the current challenges facing international collaboration in particle physics. The closure of the SSC in 1993 marked a pivotal moment, shifting the focus of high-energy physics towards Europe. Michael Riordan, a physicist and historian, noted that the U.S. push for independence in high-energy physics had unintended consequences, ultimately leading to reduced capabilities in the field.

Contemporary political tensions even affected attendance at the symposium. Some U.S. physicists were restricted from participating due to budget cuts and increased travel limitations, prompting one researcher to attend at personal expense. Discussions also emerged regarding representation and recognition of physicists from the former Soviet Union, with notable figures like Gersh Budker being highlighted for their contributions, despite some historical oversights.

As the symposium concluded on World Science Day for Peace and Development, it emphasized CERN’s vision of fostering international collaboration in science. A public screening of the documentary film The Peace Particle illustrated this vision, showcasing CERN as “Mankind’s biggest experiment…science for peace in a divided world.” Nevertheless, participants voiced concerns over CERN’s perceived silence on geopolitical issues, particularly regarding the ongoing conflicts in Ukraine and Israel.

The keynote address by John Krige, a science historian, centered on CERN’s foundational aspirations to not only advance European science post-World War II but also to contribute positively to global relations. He reminded attendees that the founders envisioned CERN as a mechanism for enhancing international cooperation in science.

In conclusion, Llewellyn Smith cautioned that the hope for future global collaborations in high-energy physics is diminishing, stating, “The perennial hope that the next big high-energy project will be genuinely global seems to be receding over the horizon due to the polarization of world politics.” The symposium served as a reminder of both the accomplishments and the obstacles within the field of particle physics, underscoring the need for renewed dialogue and cooperation in an increasingly fragmented world.