A new project has recently been proposed for Cern: the creation of a new collider called Future Circular Collider (FCC) that will continue and expand the work currently done at the Large Hadron Collider (LHC). The LHC hosts a number of large international experiments (including Atlas and CMS) that over the past years have explored the outcomes of proton-proton collisions at energies of 8 TeV (and 13 TeV in the second round).
The new Future Circular Collider will increase the energy of the collisions to 100 TeV. A more powerful collider will be able to explore energy regions that currently fall outside the sensitivity of the LHC and investigate a wider-range of collisions: not just proton-proton collisions (as in the LHC) or electron-positron collisions (as with the old LEP) but also proton-electron collisions. The FCC is an international collaboration of 150 universities and industrial partners and the plan is currently under consideration as part of the European Particle Physics Strategy.
In an era where climate change is becoming a dangerous emergency, and many other challenges face our society (including finding a cure for cancer and Alzheimer, among many others), the idea of investing money in the creation of a more powerful collider at Cern (indeed what promises to be the largest collider in the world) might strike some as blue sky thinking at best; otiose at worst. To the eye of the general public, that money should be spent looking for a new physics beyond the Standard Model (as FCC promises to do) just is not the top of the priorities (maybe not even approaching the lower end of the priorities). And yet, I maintain, we should care (and care deeply) about the tremendous international scientific effort behind the FCC. In what follows, I am going to give three reasons for it.
Fundamental research and its benefits to society
The first (and more mundane) reason concerns the wider long-term benefits to society that come from developing a range of technologies associated with a project of this nature. It is not just the World Wide Web that was originally developed by British scientist Tim Berners-Lee while working at Cern. The very first PET scan, now routinely used for cancer diagnostics among other, took place at Cern in 1977 using technology originally developed for particle physics. And Cern is still actively involved in researching new therapies for cancer (such as proton beam therapy — see this recent workshop). More in general, Cern continues to play a pivotal educational role: 70% of the graduate students in physics that have trained at Cern do not remain at Cern but apply their knowledge and skills in a variety of technological and statistical fields in society. But leaving aside the practical reasons as to why investing in colliders is a way of investing in long-term benefits for society at large, let me come to some more philosophical and methodological considerations.
I am a philosopher of science and I spend most of my time studying what scientists do, what methods they choose to investigate particular phenomena, how they go about building models with the hope to find new particles, and so on. My job as a philosopher of science is to step back and take a long view on broader (philosophical) issues such as evidence, progress, and truth in science (among others). And I cannot help but feeling dismayed when I read in social media and other outlets comments (the New York Times among them) to the effect that we should not invest in a new collider because the predictions for a new physics Beyond the Standard Model (BSM) have proved false, and not enough progress has been made to justify further spending. Let me briefly make two considerations about prediction and progress, respectively.