An ancient idea is still alive in the most advanced theory of physics today: that matter consists of a set of ultimate particles. But the obsession with going beyond the Standard Model and finding more and more particles to solve the problems of physics is victim to a theoretical and experimental framework that has run its course. Sabine Hossenfelder, Gavin Salam, and Bjørn Ekeberg debate the future of particle physics at HowTheLightGetsIn festival.

The question of what the material world around us is made of, and whether that stuff - matter - is infinitely divisible or if at some point we reach the pixels of existence started out as a philosophical one. Democritus, born around 460 BC, thought he could answer it using reason alone. Matter couldn’t possibly be infinitely divisible, theorised Democritus. It therefore consisted of “atoms”, from the Greek word for indivisible – the ultimate units of matter that could not be broken down any further. This ancient idea is in still alive in the most advanced theory of physics today, The Standard Model. Particle physics may have given the name “atom” away prematurely, as we later discovered that what we today call atoms do have constituent parts, other particles - electrons, protons, and neutrons, which in turn are made of other, more fundamental particles. In total, the Standard Model inventory contains a total of 17 particles.