Introduction to Particle and Astroparticle Physics • Rutherford • Quàntica

Multi-messenger adventures

Introduction to Particle and Astroparticle Physics: Multimessenger Astronomy and its Particle Physics Foundations (2nd edn), by Alessandro De Angelis and Mário Pimenta, Springer

Mixed messages

Recent years have seen enormous progress in astroparticle physics, with the detection of gravitational waves, very-high-energy neutrinos, combined neutrino–gamma observation and the discovery of a binary neutron-star merger, which was seen across the electromagnetic spectrum by some 70 observatories. These important advances opened a new and fascinating era for multi-messenger astronomy, which is the study of astronomical phenomena based on the coordinated observation and interpretation of disparate “messenger” signals.

This book, first published in 2015, is now released in a renewed version to include such recent discoveries and to describe present research lines.

The Standard Model (SM) of particle physics and the lambda-cold-dark-matter theory, also referred to as the SM of cosmology, have both proved to be tremendously successful. However, they leave a few important unsolved puzzles. One issue is that we are still missing a description of the main ingredients of the universe from an energy-budget perspective. This volume provides a clear and updated description of the field, preparing and possibly inspiring students towards a solution to these puzzles.

The book introduces particle physics together with astrophysics and cosmology, starting from experiments and observations. Written by experimentalists actively working on astroparticle physics and with extensive experience in sub-nuclear physics, it provides a unified view of these fields, reflecting the very rapid advances that are being made.

The first eight chapters are devoted to the construction of the SM of particle physics, beginning from the Rutherford experiment up to the discovery of the Higgs particle and the study of its decay channels. The next chapter describes the SM of cosmology and the dark universe. Starting from the observational pillars of cosmology (the expansion of the universe, the cosmic microwave background and primordial nucleosynthesis), it moves on to a discussion about the origins and the future of our universe. Astrophysical evidence for dark matter is presented and its possible constituents and their detection are discussed. A separate chapter is devoted to neutrinos, covering natural and man-made sources; it presents the state of the art and the future prospects in a detailed way. Next, the “messengers from the high-energy universe”, such as high-energy charged cosmic rays, gamma rays, neutrinos and gravitational waves, are explored. A final chapter is devoted to astrobiology and the relations between fundamental physics and life.

This book offers a well-balanced introduction to particle and astroparticle physics, requiring only a basic background of classical and quantum physics. It is certainly a valuable resource that can be used as a self-study book, a reference or a textbook. In the preface, the authors suggest how different parts of the essay can serve as introductory courses on particle physics and astrophysics, and for advanced classes of high-energy astroparticle physics. Its 700+ pages allow for a detailed and clear presentation of the material, contain many useful references and include proposed exercises.

Giovanni Fiorentini, INFN and University of Ferrara.



DVD documentary, Spacegirls Production Ltd

Professor Radium, the Atom Splitter, the Crocodile. Each is a nickname pointing to Ernest Rutherford, who made history by explaining radioactivity, discovering the proton and splitting the atom. All his scientific and personal milestones are described in great detail in the three-part documentary Rutherford, produced by Spacegirls Production Ltd in 2011.

Accompanied by physics historian John Campbell, the viewer learns about this great scientist from his ordinary childhood as a “Kiwi boy” to his untimely death in 1937. Historical reconstructions and trips to the places (New Zealand, the UK and Canada) that characterised his life bring Rutherford back to life.

When it was still heresy to think that there existed objects smaller than an atom, Rutherford was exploring the secrets of the invisible. During his first stay in Cambridge (UK), he discovered that uranium emits two types of radiation, which he named alpha and beta. Then, continuing his research at McGill University (Canada), he discovered that radioactivity has to do with the instability of the atom. He was rewarded with the Nobel Prize in Chemistry in 1908, and called Professor Radium after a comic book character of that name. In those years, people did not know the effects of radiation and “radio-toothpaste” was available to buy.

Then in Manchester (UK), he conducted the first artificial-induced nuclear reaction and described a new model of the atom, where a proton is like a fly in the middle of an empty cathedral. He fired alpha particles at nitrogen
gas and obtained oxygen plus hydrogen, thus the epithet of the world’s first “atom splitter”.

In-between these big discoveries, the documentary points out that Rutherford blew tobacco smoke into his ionisation chamber, providing the groundwork for modern smoke detectors, proposed a more accurate dating system for the Earth’s age based on the rate of decay of uranium atoms, and campaigned for women’s opportunities and saving scientists from war.

The name “Crocodile” came later, from soviet physicist Pyotr Kapitza, as it is an animal that never turns back – or perhaps a reference to Rutherford’s loud voice that preceded his visits. The carving of a crocodile on the outer wall of the Mond Laboratory at the Cavendish site, commissioned by Kapitza, still reminds Cambridge students and tourists of this outstanding physicist.

Letizia Diamante, CERN.



Exhibition, Barcelona, 9 April – 24 September

Knowledge sharing

Take a leap and enter, past the chalkboard wall filled with mathematical equations written, erased and written again, into the darkened room of projected questions where it all begins. What is reality? How do we describe nature? And for that matter, what is science and what is art?

Quàntica, which opened on 9 April at the Centre de Cultural Contemporània de Barcelona, invites you to explore quantum physics through the lens of both art and science. Curated by Mónica Bello, head of Arts at CERN, and art curator José-Carlos Mariátegui, with particle physicist José Ignacio Latorre serving as its scientific adviser, Quàntica is the second iteration of an exhibition that brings together 10 artworks resulting from Collide International art residences at CERN.

The exhibition illustrates how interdisciplinary intersections can present scientific concepts regarded by the wider public as esoteric, in ways that bridge the gap, engage the senses and create meaning. Punctuating each piece is the idea that the principles of quantum physics, whether we like it or not, are pervasive in our lives today – from technological applications in smart phones and satellites to our philosophies and world views.

Nine key concepts – “scales”, “quantum states”, “overlap”, “intertwining”, “indeterminacy”, “randomness”, “open science”, “everyday quantum” and “change-evolution” – guide visitors through the meandering hallway. Each display point prompts pause to consider a question that underlies the fundamental principles of quantum physics. Juxtaposed in the shared space is an artist-made particle detector and parts of experiments displayed as artistic objects. Video art installations are interspersed with video interviews of CERN physicists, including Helga Timko, who asks: what if we were to teach children quantum physics at a very young age, would they perceive the world as we do? On the ceiling above is a projection of a spiral galaxy, a part of Juan Cortés’ Supralunar. Inspired by Vera Rubin’s work on dark matter and the rotational motion of galaxies, Cortés made a two-part multisensorial installation: a lens through which you see flashing lights and vibrating plates to rest your chin and experience, on some level, the intensity of a galaxy’s formation.

From the very large scale, move to the very small. A recording of Richard Feynman explaining the astonishing double-slit experiment plays next to a standing demonstration allowing you to observe the counterintuitive possibilities that exist at the subatomic level. You can put on goofy glasses for Lea Porsager’s Cosmic Strike, an artwork with a sense of humour, which offers an immersive 3D animation described as “hard science and loopy mysticism”. She engages the audience’s imagination to meditate on being a neutrino as it travels through the neutrino horn, one of the many scientific artefacts from CERN’s archives that pepper the path.

Around the corner is Erwin Schrödinger’s 1935 article where he first used the word “Verschränkung” (or entanglement) and Anton Zeilinger’s notes explaining the protocol for quantum teleportation. Above these is projected a scene from Star Trek, which popularised the idea of teleportation.

The most visually striking piece in the exhibition is Cascade by Yunchul Kim, made up of three live elements. The first part is Argos (see image), splayed metallic hands that hang like lamps from the ceiling – an operational muon detector made of 41 channels blinking light as it records the particles passing through the gallery. Each signal triggers the second element, Impulse, a chandelier-like fluid-transfer system that sends drops of liquid through microtubes that flow into transparent veins of the final element, Tubular. Kim, who won the 2016 Arts at CERN Collide International Award, is an artist who employs rigorous methods and experiments in his laboratory with liquid and materials. Cascade encapsulates the surprising results knowledge-sharing can yield.

Quàntica is a must-see for anyone who views art and science as opposite ends of the academic spectrum. The first version of the exhibition was held at Liverpool in the UK last year. Co-produced by the ScANNER network (CERN, FACT, CCCB, iMAL and Le Lieu Unique), the exhibition continues until 24 September in Barcelona, before travelling to Brussels.

Abha Eli Phoboo, CERN.