Leading experts at the world’s foremost particle accelerator have unveiled a comprehensive plan for a significantly larger successor, aimed at advancing research into the mysteries that have long puzzled physicists. The detailed proposal for the Future Circular Collider (FCC) was published this week, outlining a vision developed over ten years by CERN, the European Organization for Nuclear Research. The proposed collider would span nearly 91 kilometers (56.5 miles), crossing the French-Swiss border and extending beneath Lake Geneva.
Envisioned to conduct high-precision experiments in the mid-2040s, the FCC aims to explore “known physics” with unprecedented detail. A second phase, projected for 2070, plans to engage in high-energy collisions of protons and heavy ions, promising to uncover new realms of knowledge, according to Giorgio Chiarelli from Italy’s National Institute of Nuclear Physics. Chiarelli underscores that historically, increased data volumes in physics lead to more unexpected insights, a testament to human ingenuity.
Over the past decade, CERN’s scientific community has been crafting plans for the successor to the Large Hadron Collider (LHC), a sophisticated network of magnets designed to propel particles through a 27-kilometer (17-mile) underground circuit, ultimately colliding them at near-light speeds. The FCC blueprint details its proposed trajectory, environmental implications, scientific objectives, and estimated costs. Independent assessments will precede a decision from CERN’s member countries, mostly European plus Israel, slated for 2028 whether to initiate the project in the mid-2040s, with an estimated funding need of 14 billion Swiss francs (around $16 billion).
CERN promotes the potential scientific breakthroughs that this project could ignite, potentially advancing sectors such as cryogenics, superconducting magnets, and vacuum technologies with broad human benefits. Externally, experts highlight the prospect of deepening understanding of the Higgs boson, a particle described as “the God particle,” which provides insight into how matter emerged following the Big Bang. The LHC’s 2013 work confirmed the existence of the Higgs boson, a central component in the standard model that explains certain fundamental forces in the universe.
CERN Director-General Fabiola Gianotti lauds the future collider as possibly the most extraordinary scientific instrument ever created. Its dual objectives are to enhance Higgs boson research and break new ground by exploring the energy frontier and seeking unknown physics to elucidate the universe’s structure and evolution. However, there remains uncertainty regarding the United States’ future support. The current administration’s fiscal policies have seen cutbacks in foreign aid and research funding, despite prior support pledged under President Biden for the study, collaboration, and potential construction of the FCC.
The United States accounts for the largest national group among CERN’s 17,000 users, with around 2,000 American participants, both on-site and consulting externally. While the U.S. has an observational role at CERN rather than membership, it invests in specific projects rather than the regular budget, which is primarily funded by European contributions.
According to Costas Fountas, President of the CERN Council, discussions with U.S. National Science Foundation and Department of Energy personnel have indicated that, to date, U.S. contributions remain “under the radar” of budgetary reductions under the Trump administration. For the FCC, CERN leaders considered over 100 different configurations before deciding on a 91-kilometer circumference, reaching an average depth of 200 meters (656 feet). The tunnel is planned to have a diameter of roughly 5 meters (16 feet), promising a bold step forward in the exploration of particle physics.