THE STANDARD MODEL OF MATTER: TRIBUTE TO THE 20TH CENTURY
Sofia Imber Museum of Contemporary Art, Caracas, Venezuela
The Standard Model of Matter
by Claudio Mendoza (Astrophysicist Head of the Physics Center, IVIC)
Paris, July 1997
The almost complete understanding of the fundamental building blocks of matter and their interactions, a model referred to as the standard model of matter, is without doubt one of the greatest scientific achievements of the 20th century. The initial idea that matter was composed of basic units, that is of "atoms", was first proposed by the Greek thinkers (Leucippus, Democritus, Epicure and Lucretius). After two and a half millennia and a never-ending opening of Russian matryoshka dolls by the most gifted human minds - with definitive theoretical and experimental verifications only being completed in the last few years (in the middle 1990s to be precise) - atomism reigns as the sovereign paradigm of the physical sciences. The standard model is perhaps the main collective present of the current era to the future.
It is virtually impossible to make a comprehensive list of the scientists that have been involved in this quest, or even of the main distinguished contributors. We only give here a very quick yet apparently crowded overview to stress this point. The physical foundations were established from the beginning of the 17th century by Galileo, Newton and Maxwell, among others, and alchemy progressively migrated to atomic chemistry during the 1 8th and 19th centuries with the gigantic steps of Priestley, Cavendish, Lavoisier, Dalton, Berzelius, Avogadro, Gay-Lussac, Boltzmann and Mendeleev. Just before the turn of the 20th century, JJ Thomson discovered the electron, and soon after the experiments of Rutherford resulted in a nuclear atom. The work on radioactivity by Becquerel, Pierre and Marie Curie, the discoveries of the neutron (Chadwick) and the positron (Anderson) and the nuclear reactors of Enrico Fermi provided definitive signals of lower levels of matter. The creators of quantum mechanics in the first three decades, Planck, Bohr, Heisenberg, de Broglie, Einstein, Pauli, Schrödinger, Born and Dirac, provided a very powerful theory for digging into the most intimate microcosm of nature, and the attainment of the standard model is in great part due to them. The quarks, the fundamental building particles of matter, were originally proposed as mathematical entities in the 60s by Gell-Mann and Zweig, but were later experimentally detected in the first generation of accelerators by Friedman Kendall and Taylor giving the coup de grace to the alternative theory of nuclear democracy. The unification efforts by Weinberg, Salam and Glashow were paid off with the final experimental verifications of the standard model by the lane teams of scientists led by Ting, Richter, Lederman and Rubbia on both sides of the Atlantic which culminated in the middle 90s.
The standard model postulates that matter is composed of three generations of elementary particles and involves three forces: electromagnetic, strong and weak. The fourth force, gravity, responsible for the macrostructure of the cosmos, has not been integrated to the model. The universe is almost totally composed of particles belonging to Generation I; the other two generations are responsible for exotic and unstable matter found at high energies. Each generation consists of two quarks, particles with fractional electric charge (+2/3 and —1 /3), and two leptons of respectively neutral the neutrino) and negative H) charges. The forces take place by interchange of mediating particles known as bosons. The electro-magnetic interaction occurs between electrically charged particles by photon (γ) exchange and Oyes rise to light. The strong nuclear interaction is only felt by the quark Color charge due to the exchange of gluons (g), and is responsible for the atomic nucleus stability. The weak nuclear interaction transforms the particle type (flavor) and is mediated by the W and Z bosons.
The installation proposed by the Venezuelan artist Rolando Peña in this context is a humble yet correctly scaled end-of-century tribute to all those that have devoted their lives to experiment, understand and celebrate natural phenomena, adopting the standard model as the central theme to be developed. It specially celebrates the 40th birthday of the Venezuelan Institute for Scientific Research (IVIC). It makes references to the early manifestations depicted in constructions such as Stonehenge, the Mayan pyramids, Inca ruins and Greek temples, to the more contemporary particle accelerators and to the structure of the standard model itself. The installation also evokes the abuse, greed and ecological neglect that have resulted from the misuse of the powers that emerged from this scientific search.
It is worth mentioning that the media used by Rolando Peña in his installations are particularly suitable to describe the atom. He makes extensive use of a "golden oil barrel" as the basic building block for large-scale structures such as totems, walk, spirals, pyramids, labyrinths, etc., rooted in the ancient and religious traditions of monument builders. This module and icon brings about the important relation between the richness of the Earth (black content) and the illusive wealth of the miner (gold container). Moreover, since the barrel although being a simple cylindrical container is also a unit of energy, it can be effectively y used to depict the equivalence of particle and energy which is central to the discussion of the standard model.
There are other elements in his installations that can be related to important scientific issues concerning the forces of nature. For instance, the frequent use of mirrors quickly reminds us of the importance of symmetry in the scientific description of such forces; the feeling of confusion and uncertainty found in El Laberinto and his recurrent treatment of virtually (e.g. Piramide Virtual) are indeed connected with a personal obsession with Heisenberg's Uncertainty Principle; and more recently, he has been concerned with the principles of cycles and recycling (El Derrame), which stimulate thoughts related to the irreversible disruption of ecological balance and some of the important concepts that emerged from the cybernetics movement of Wiener in the 50s such as the feedback cycle.
Peña has also recently experimented in his work with computers, synthetic digital images and the World Wide Web. In this respect, the installation makes full use of multimedia: interactive screens, video, sound and the release of a CD-ROM with the highlights of the standard model to celebrate the event.