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In a very personal reflective essay, Marzio Nessi, the technical coordinator of the ATLAS Collaboration at CERN, recounts Max Boisot’s work and interaction with the particle physics community at ATLAS and CERN, whose research on the Higgs particle, the famous “God particle”, has attracted a lot of media attention. Boisot was interested in the creation of knowledge at ATLAS and studied its unique organization, characterized by collaborative behavior, a bottom-up approach, and a consensus-driven management style, which has enabled this Big Science institution to create a new way of dealing with extreme complexity. Boisot was fascinated by how a scientific collaboration as large as ATLAS generates and sustains creative and constructive interactions among thousands of researchers from diverse cultures, traditions and habits. He believed that the self-organizational capability of the collaboration was the key to success. Boisot’s research also laid the ground for studying how scientific and technical progress is made and how the value of basic research can be captured for society.

Anaximander thought water is a bad idea for a primary substance of the universe because it’s not neutral—it has an opposite, fire. And opposites destroy; they don’t generate one another. If everything in the universe were initially water, it would be impossible to have its opposite, fire, ever created because water destroys fire. Thus, quarks and leptons can’t be primary, for they have opposites, their antimatter versions, and as opposites, matter and antimatter annihilate, not generate, each other. Anaximander taught everything is generated from the apeiron: a timeless, neutral substance, encompassing the universe and constantly transforming into competing transient opposites, but with measure to preserve the cosmic justice—without absolute dominance by either opposite. In physics, it’s ubiquitous energy that’s constantly transforming into competing opposites—matter and antimatter—with measure. Curiously, however, matter (“water”) is more plentiful than antimatter (“fire”). Why? Nobody knows. Where’s the cosmic justice?

The Standard Model (SM) 2020 of weak, electromagnetic and strong interactions, based on gauge symmetry and spontaneous symmetry breaking, describes all known fundamental interactions at the microscopic scale except gravity and, perhaps, interactions with dark matter. The SM model has been tested systematically in collider experiments, and in the case of strong interactions (quantum chromodynamics) also with numerical simulations. With the discovery in 2012 of the Higgs particle at the Large Hadron Collider (LHC) at the European Council for Nuclear Research (CERN), all particles of the SM have been identified, and most parameters have been measured. Still, the Higgs particle remains the most mysterious particle of the SM, since it is responsible for all the parameters of the SM except gauge couplings and since it leads to the fine-tuning problem. The discovery of its origin, and the precise study of its properties should be, in the future, one of the most important field of research in particle physics. Since we know now that the neutrinos have masses, the simplest extension of the SM implies Dirac neutrinos. With such a minimal modification, consistent so far (2020) with experimental data, the lepton and quark sectors have analogous structures: the lepton sector involves a mixing matrix, like the quark sector (three angles have been determined, the fourth charge conjugation parity (CP) violating angle is still unknown).

Chapter 4 describes a few important steps which have led from the discovery of infinities in quantum electrodynamics in the calculation of Feynman diagrams (ultraviolet divergences (UV divergences)) to the concept of renormalization and renormalization groups (RG). The constructions of quantum (or statistical) field theories (QFTs) and the deeply related RG have been some of the major theoretical achievements in physics of the last century. RG today plays an essential role in the understanding of the properties of QFT and of continuous macroscopic phase transitions. The existence of RG fixed points makes it possible to understand universality when there is no scale decoupling. In particle physics, it leads to the notion of effective field theory and the fine tuning problem in the Higgs particle sector.