More Is Different

This book presents articles written by leading experts surveying several major subfields in Condensed Matter Physics and related sciences. The articles are based on invited talks presented at a recent conference honoring Nobel laureate Philip W. Anderson of Princeton University, who coined the phrase "More is different" while formulating his contention that all fields of physics, indeed all of science, involve equally fundamental insights. The articles introduce and survey current research in areas that have been close to Anderson's interests. Together, they illustrate both the deep impact that Anderson has had in this multifaceted field during the past half century and the progress spawned by his insights. The contributors cover numerous topics under the umbrellas of superconductivity, superfluidity, magnetism, electron localization, strongly interacting electronic systems, heavy fermions, and disorder and frustration in glass and spin-glass systems. They also describe interdisciplinary areas such as the science of olfaction and color vision, the screening of macroions in electrolytes, scaling and renormalization in cosmology, forest fires and the spread of measles, and the investigation of "NP-complete" problems in computer science. The articles are authored by Philip W. Anderson, Per Bak and Kan Chen, G. Baskaran, Juan Carlos Campuzano, Paul Chaikin, John Hopfield, Bernhard Keimer, Scott Kirkpatrick and Bart Selman, Gabriel Kotliar, Patrick Lee, Yoshiteru Maeno, Marc Mezard, Douglas Osheroff et al., H. R. Ott, L. Pietronero et al., T. V. Ramakrishnan, A. Ramirez, Myriam Sarachik, T. Senthil and Matthew P. A. Fisher, B. I. Shklovskii et al., and F. Steglich et al.

The physics of condensed matter, in contrast to quantum physics or cosmology, is not traditionally associated with deep philosophical questions. However, as science - largely thanks to more powerful computers - becomes capable of analysing and modelling ever more complex many-body systems, basic questions of philosophical relevance arise. Questions about the emergence of structure, the nature of cooperative behaviour, the implications of the second law, the quantum-classical transition and many other issues. This book is a collection of essays by leading physicists and philosophers. Each investigates one or more of these issues, making use of examples from modern condensed matter research. Physicists and philosophers alike will find surprising and stimulating ideas in these pages.

I. Personal reminiscences. Introduction. "BCS" and me. A mile of dirty lead wire: a fable for the scientifically literate. Scientific and personal reminiscences of Ryogo Kubo -- II. History. Introduction. Physics at Bell Labs, 1949-1984: young Turks and younger Turks. It's not over till the fat lady sings. Reflections on twentieth century physics: historical overview of the 20t century in Physics. 21st century Physics. Y. Nambu and broken symmetry. Nevill Mott, John Slater, and the "magnetic state": winning the prize and losing the PR battle -- III. Philosophy and sociology. Introduction. Emergence vs. reductionism. Is the theory of everything the theory of anything? Is measurement itself an emergent property? Good news and bad news. The future lies ahead. Could modern America have invented wave mechanics?. Loose ends and Gordian knots of the string cult. Imaginary friend, who art in heaven -- IV. Science tactics and strategy. Introduction. Solid state experimentalists: theory should be on tap, not on top. Shadows of doubt. The Reverend Thomas Bayes, needles in haystacks, and the fifth force. Emerging physics. On the nature of physical laws. On the "unreasonable efficacy of mathematics"--A proposition by Wigner. When scientists go astray. Further investigations -- V. Genius. Introduction. What mad pursuit. Complexities of Feynman coffee-table complexities. Search for polymath's elementary particles. Giant who started the silicon age. The quiet man of physics. A theoretical physicist. Some thoughtful words (not mine) on research strategy for theorists -- VI. Science wars. Introduction. They think it's all over. Science: a 'dappled world' or a 'seamless web'? Reply to Cartwright. Postmodernism, politics and religion -- VII. Politics and science. Introduction. Politics and science. The case against Star Wars. A dialogue about Star Wars. No facts, just the right answers -- VIII. Futurology. Introduction. Futurology. Dizzy with future Schlock. Einstein and the p-branes. Forecaster fails to detect any clouds -- IX. Complexity. Introduction. Physics: the opening to complexity. Is complexity physics? Is it science? What is it? Complexity II: the Santa Fe Institute. Whole truths false in part -- X. Popularization attempts. Introduction. Who or what is RVB? More on RVB. Brainwashed by Feynman? Just exactly what do you do, Dr. Anderson? What is a condensed matter theorist? Global economy II: or, how do you follow a great act?

This book presents articles written by leading experts surveying several major subfields in Condensed Matter Physics and related sciences. The articles are based on invited talks presented at a recent conference honoring Nobel laureate Philip W. Anderson of Princeton University, who coined the phrase "More is different" while formulating his contention that all fields of physics, indeed all of science, involve equally fundamental insights. The articles introduce and survey current research in areas that have been close to Anderson's interests. Together, they illustrate both the deep impact that Anderson has had in this multifaceted field during the past half century and the progress spawned by his insights. The contributors cover numerous topics under the umbrellas of superconductivity, superfluidity, magnetism, electron localization, strongly interacting electronic systems, heavy fermions, and disorder and frustration in glass and spin-glass systems. They also describe interdisciplinary areas such as the science of olfaction and color vision, the screening of macroions in electrolytes, scaling and renormalization in cosmology, forest fires and the spread of measles, and the investigation of "NP-complete" problems in computer science. The articles are authored by Philip W. Anderson, Per Bak and Kan Chen, G. Baskaran, Juan Carlos Campuzano, Paul Chaikin, John Hopfield, Bernhard Keimer, Scott Kirkpatrick and Bart Selman, Gabriel Kotliar, Patrick Lee, Yoshiteru Maeno, Marc Mezard, Douglas Osheroff et al., H. R. Ott, L. Pietronero et al., T. V. Ramakrishnan, A. Ramirez, Myriam Sarachik, T. Senthil and Matthew P. A. Fisher, B. I. Shklovskii et al., and F. Steglich et al.

The main purpose of this book is to introduce a broader audience to emergence by illustrating how discoveries in the physical sciences have informed the ways we think about it. In a nutshell, emergence asserts that non-reductive behavior arises at higher levels of organization and complexity. As physicist Philip Anderson put it, “more is different.” Along the text's conversational tour through the terrain of quantum physics, phase transitions, nonlinear and statistical physics, networks and complexity, the author highlights the various philosophical nuances that arise in encounters with emergence. The final part of the book zooms out to reflect on some larger lessons that emergence affords us. One of those larger lessons is the realization that the great diversity of theories and models, and the great variety of independent explanatory frameworks, will always be with us in the sciences and beyond. There is no “Theory of Everything” just around the corner waiting to be discovered. One of the main benefits of this book is that it will make a number of exciting scientific concepts that are not normally covered at this level accessible to a broader audience. The overall presentation, including the use of examples, analogies, metaphors, and biographical interludes, is geared for the educated non-specialist.

These lecture notes constitute a course on a number of central concepts of solid state physics ? classification of solids, band theory, the developments in one-electron band theory in the presence of perturbation, effective Hamiltonian theory, elementary excitations and the various types of collective elementary excitation (excitons, spin waves and phonons), the Fermi liquid, ferromagnetic spin waves, antiferromagnetic spin waves and the theory of broken symmetry.The book can be used in conjunction with a survey course in solid state physics, or as the basis of a first graduate-level course. It can be read by anyone who has had basic grounding in quantum mechanics.

A Mind Over Matter is a biography of the Nobel-prize winner Philip W. Anderson, a person widely regarded as one of the most accomplished and influential physicists of the second half of the twentieth century. Anderson (1923-2020) was a theoretician who specialized in the physics of matter, including window glass and metals, magnets and semiconductors, liquid crystals and superconductors. More than any other single person, Anderson transformed the patchwork subject of solid-state physics into the deep, subtle, and coherent discipline known today as condensed matter physics. Among his many world-class research achievements, Anderson discovered an aspect of wave physics that had been missed by all previous scientists going back to Isaac Newton. He became a public figure when he testified before Congress to oppose its funding of an expensive project intended exclusively for particle physics research. Over the years, he published many articles designed to influence a broad audience about issues where science impacted public policy and culture. Anderson grew up in the American mid-west, was educated at Harvard, and rose to the pinnacle of his profession during the first decade of his thirty-five career as a theoretical physicist at Bell Telephone Laboratories. Almost uniquely, he spent many years working half-time as a professor at the University of Cambridge and at Princeton University. The outspoken Anderson enjoyed broad influence outside of physics when he helped develop and champion the concepts of emergence and complexity as organizing principles to help attack very difficult problems in technically challenging disciplines.

One of the pathways by which the scientific community confirms the validity of a new scientific discovery is by repeating the research that produced it. When a scientific effort fails to independently confirm the computations or results of a previous study, some fear that it may be a symptom of a lack of rigor in science, while others argue that such an observed inconsistency can be an important precursor to new discovery. Concerns about reproducibility and replicability have been expressed in both scientific and popular media. As these concerns came to light, Congress requested that the National Academies of Sciences, Engineering, and Medicine conduct a study to assess the extent of issues related to reproducibility and replicability and to offer recommendations for improving rigor and transparency in scientific research. Reproducibility and Replicability in Science defines reproducibility and replicability and examines the factors that may lead to non-reproducibility and non-replicability in research. Unlike the typical expectation of reproducibility between two computations, expectations about replicability are more nuanced, and in some cases a lack of replicability can aid the process of scientific discovery. This report provides recommendations to researchers, academic institutions, journals, and funders on steps they can take to improve reproducibility and replicability in science.