FST BLOG

Science Policy and the long-term future of High Energy Physics

• 22 April 2020
• General
• Conor Fitzpatrick

The continued quest for deeper understanding of our universe pushes the boundaries of more than just scientific techniques: It puts significant pressure on researchers to take the long-term view when preparing input to policy.

As I sit on a wonky chair at a makeshift desk at home, hastily put into action for an uncertain period of time, I am drawn to thinking about the consequences of decisions made now that have long term effects. My area of research, High Energy Physics (HEP), has an interesting and storied history in this regard, because as a field it can all too easily be summarised as expensive and of limited short-term utility. Much of publicly funded fundamental science doesn't have immediately obvious short term applications in everyday life, but the increasingly large, and increasingly long-term nature of High-Energy Physics experiments requires a level of planning and collaboration beyond that of other fields.

The relationship between energy and time in High Energy Physics stems from the way in which our universe evolved: Back at the very earliest stages the universe was dense and hot, allowing particles to interact very differently to the way in which they interact now in our comparatively cooler present day. By building ever larger, more powerful colliders, we can achieve energies present further back in time, and so we may study particles that could only have been produced increasingly early on. Larger colliders are of course more expensive, and take longer to develop and build. In the 1950's it was realised that collaboration between European countries would allow larger facilities at the forefront of science and return research and technical expertise required to build it to Europe after the war. Thus, CERN was born as a laboratory shared between member states. The Large Hadron Collider (LHC) is the jewel in CERN's crown, the highest energy collider ever built and a testament both to international cooperation, and to successful scientific policymaking, resulting in the discovery in 2012 of the Higgs Boson, one of the missing pieces of the particle physics puzzle. The LHC was in large part sold to policymakers as a 'no-lose' proposition: Either the LHC would find the Higgs, or it would find an entirely new understanding of our universe to account for not finding it. This scientific case was sufficient to rally a large international community of enthusiastic scientists to make their case heard at the national policymaking level.

Where the LHC's no-lose proposition can be seen as a success of scientific policymaking and a victory for a European laboratory, things may have turned out very differently. The LHC was first conceived in the early 1980's, taking a little over 30 years from conception to its headline discovery. Election cycles on 4-5 year timescales mean long-term projects with limited short-term payoff or that are hard to explain to the public are unlikely to gather commitment without support of the community, and CERN plays a significant part in that process, and the long-term commitment that membership of CERN requires enables funding to transcend typical governmental timescales. This was not the case elsewhere: While the LHC was still in the planning stages, an even larger scale collider was underway in Waxahachie, Texas. The Superconducting Supercollider (SSC) was intended to be three times larger and three times higher energy than the LHC. In 1993, after a little more than a quarter of its 87km circumference tunnel had been built, it was cancelled by congress in part due to the high cost of the project and dissenting arguments from scientists that smaller scale projects in other fields would generate greater short-term utility. Had the SSC been completed, there might have been fierce competition between the US and Europe in chasing the Higgs Boson, and it may even have been discovered in Texas rather than on the Franco-Swiss border. Instead, the required approval every year for US funding of the SSC made its failure almost inevitable. The US now focuses on different areas, and a fruitful exchange of expertise between Europe and the US on future colliders in Europe and future Neutrino experiments in the US has taken the place of direct competition, with the US-based Deep Underground Neutrino Experiment (DUNE) being funded in a different manner to the SSC in order to attract non-US collaborators and ensure longer-term commitments. 

And so we return to my long-term predicament. Should I buy an office chair to replace my temporary fix, or gamble on how quickly we return to our offices?

The lessons to be learned from the failure of the SSC and the success of the LHC may soon be put into practice once more. The European Strategy for Particle Physics Update is underway: A two-year exercise in which the particle physics community is consulted on the long-term direction of the field in Europe, and to which policymakers are invited. Similar consultations are underway in the US and Japan, and it is hoped that consensus can be reached in a way that optimises resources and research efforts globally, presenting a unified message as input to national-level policymaking. I say hope, but this is by no means a trivial exercise for a number of reasons: The LHC's 'no-lose' selling point is not easily recycled for future colliders. We have now discovered the Higgs, and the LHC has not yet provided us with a future direction by which we can guarantee a similar success from a future collider, at least not yet in a policy-friendly way.

Several competing designs for future colliders are under development, each with their own merits and each with their limitations, not least of which are in terms of timescale. In some cases we are designing future colliders that may not produce scientific results for almost 50 years, meaning that many of the decisions taken by the field now will be made by people retiring 40 years before the outcomes' fruition, and on behalf of researchers that have not yet been born. An SSC-like approach, with smaller communities divided between different fields and unable to make long-term commitments would be sure to fail once more. 

If we do not as a field agree to a long term strategy for a future collider, we run the risk of losing the expertise required to build one. If however we do not have a strong scientific case for a significant outlay over the long-term, we run the risk of failing to convince policy makers of the merits of such R&D efforts. Over the lifetime of the LHC and its technological predecessors, the case has often been made for the many spin-off and spin-out advances R&D at CERN has brought, from the development of the world-wide-web to more recent activities by some of my colleagues focused on tackling COVID-19, in addition to the valuable training of researchers who return to their home countries as skilled workers. These benefits are important, but are they enough to justify significant long-term investment when the ultimate outcome is less clearly defined or consensus cannot be reached? 

My own predicament has concluded: I have clicked the 'buy' button and am awaiting delivery of a new office chair. I may even supplement it with a better desk in the coming weeks. I have reasoned that while we may be back in our offices at institutes around the world soon, I will need that chair and the ability to work from home again in future. There will always be evenings or weekends when I am approaching a deadline that I will appreciate having it. Should we remain under lockdown for an extended period the investment will have a more evident short-term payoff, but I am convinced that it is an equally good investment for the longer term. I have reevaluated my predicament and come to my own 'no-lose' proposition. I hope that as a field, High Energy Physics, through the European Strategy Update, will be able to do the same again.

Image by © 2009-2020 CERN (License: CC-BY-SA-4.0)

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