UvA-DARE (Digital Academic Repository) History of dark matter Bertone, G.; Hooper, D. DOI 10.1103/RevModPhys.90.045002 Publication date 2018 Document Version Final published version Published in Reviews of Modern Physics Link to publication Citation for published version (APA): Bertone, G., & Hooper, D. (2018). History of dark matter. Reviews of Modern Physics, 90(4), [045002]. https://doi.org/10.1103/RevModPhys.90.045002 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. 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UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl) Download date:25 Sep 2021 REVIEWS OF MODERN PHYSICS, VOLUME 90, OCTOBER–DECEMBER 2018 History of dark matter Gianfranco Bertone GRAPPA, University of Amsterdam, Science Park 904 1098XH Amsterdam, Netherlands Dan Hooper Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA and Department of Astronomy and Astrophysics, The University of Chicago, Chicago, Illinois 60637, USA (published 15 October 2018) Although dark matter is a central element of modern cosmology, the history of how it became accepted as part of the dominant paradigm is often ignored or condensed into an anecdotal account focused around the work of a few pioneering scientists. The aim of this review is to provide a broader historical perspective on the observational discoveries and the theoretical arguments that led the scientific community to adopt dark matter as an essential part of the standard cosmological model. DOI: 10.1103/RevModPhys.90.045002 CONTENTS I. PREFACE I. Preface 1 Dark matter plays a central role in our understanding of II. Prehistory 2 modern cosmology. But despite its significance, many of the A. From Epicurus to Galileo 2 scientists active in this area of research know relatively little B. Dark stars, dark planets, dark clouds 3 about its interesting history and how it came to be accepted as C. Dynamical evidence 3 the standard explanation for a wide variety of astrophysical III. Galaxy Clusters 4 observations. Most publications and presentations on this A. Zwicky and Smith 4 — — B. A confusing situation 6 topic whether at a technical or a popular level either ignore IV. Galactic Rotation Curves 7 the long history of this field or condense it into a brief A. The beginnings 7 anecdotal account, typically centered around the work on B. The 1970s revolution 8 galaxy clusters by Fritz Zwicky in the 1930s and on galactic C. Local measurements 10 rotation curves by Vera Rubin in the 1970s. Only a small V. Baryonic Dark Matter 11 number of scientists, and an even smaller number of histor- A. Gravitational microlensing 11 ians, have endeavored to systematically analyze the develop- B. The Universe’s baryon budget 12 ment of the dark matter problem from an historical C. Primordial black holes 13 perspective, and it is surprisingly hard to find articles and VI. Modified Gravity 13 books that do justice to the fascinating history of dark matter. A. Toward a realistic theory of MOND 13 The aim of this article is to provide a review of the B. Observational successes and failures 14 theoretical arguments and observations that led to the estab- VII. Dark Matter Particles 15 lishment of dark matter among the pillars of modern cosmol- A. Neutrinos 15 ogy, as well as of the theories that have been proposed to B. Supersymmetry 17 explain its nature. Although we briefly discuss some early C. Axions 19 ideas and recent developments, the focus of this review is the D. The WIMP paradigm 20 20th century, beginning with the first dynamical estimates of VIII. Piecing the Puzzle 21 ’ A. Discrepancies at all scales 21 dark matter s abundance in the Universe, and to its role in the B. Cosmology 22 current standard cosmological model, and the strategies that C. Numerical simulations 22 have been pursued to reveal its particle nature. IX. The Hunt for Dark Matter Particles 24 The first part of this review is largely based on the analysis A. Scattering with nuclei 24 of primary sources, mainly scanned versions of scientific B. Annihilation and decay 25 articles and books published in the 19th and 20th centuries, C. Axion experiments 27 freely accessible via NASA ADS and the Internet Archive Acknowledgments 27 Project. We study the emergence of the concept of dark matter Appendix: Further Reading 27 in the late 19th century and identify a series of articles and References 28 other sources that describe the first dynamical estimates for its 0034-6861=2018=90(4)=045002(32) 045002-1 © 2018 American Physical Society Gianfranco Bertone and Dan Hooper: History of dark matter abundance in the known Universe (Sec. II). We then discuss inseparable from philosophy and theology, they reveal to us the pioneering work of Zwicky within the context of the the longevity of our species’ desire to understand the world scientific developments of the early 20th century. And and its contents. although his work clearly stands out in terms of methodology Although many early civilizations imagined their own and significance, we find that his use of the term “dark matter” cosmological systems, it was arguably the ancient Greeks was in continuity with the contemporary scientific literature. who were the first to attempt the construction of such a model We then go on to follow the subsequent development of the based on reason and experience. The atomists, most famously virial discrepancy that he discovered, with particular emphasis Leucippus and Democritus who lived in the 5th century BCE, on the debate that took place around this issue in the 1960s were convinced that all matter was made of the same (Sec. III). fundamental and indivisible building blocks, called atoms, The second part of this review focuses on more recent and that these atoms were infinite in number, as was the developments, which gave us the opportunity to complement infinite space that contained them. Epicurus (341 BCE–270 the analysis of the primary sources with extensive discussions BCE) further suggested in his “Letter to Herodotus” that an with some of the pioneering scientists who contributed to the infinite number of other worlds existed as well, “some like this advancement of this field of research. We discuss the history world, others unlike it.”1 Others speculated about unobserv- of galactic rotation curves, from the early work in the 1920s able matter that might be found within our own Universe. For and 1930s to the establishment of flat rotation curves in example, the Pythagorean Philolaus conjectured the existence the 1970s, placing the famous work of Bosma and Rubin of the celestial body Antichthon, or counter-earth, which and collaborators in 1978 within the broader context of the revolves on the opposite side of the “central fire” with respect theories and observations that were available at that time to the Earth (Kragh, 2006). (Sec. IV). We then discuss the theories that have been put The cosmological model of Aristotle, which would domi- forward to explain the nature of dark matter in terms of nate discourse throughout the Middle Ages, provided an fundamental particles (Sec. VII), astrophysical objects elegant construction, in which the location of the Earth was (Sec. V), or manifestations of non-Newtonian gravity or fixed to the center of an immutable universe. This model dynamics (Sec. VI). offered what seemed to many to be strong arguments against Finally, we discuss how the emergence of cosmology as a the existence of invisible or unknown forms of matter. Even science in the 1960s and 1970s, the advent on numerical the striking appearance of comets, which had no place in simulations in the 1980s, and the convergence between Aristotle’s highly organized hierarchy of celestial spheres, was particle physics and cosmology led most of the scientific dismissed as an atmospheric phenomenon, a belief that community to accept the idea that dark matter was made continued to be held until Tycho Brahe measured the absence of nonbaryonic particles (Sec. VIII) and prompted the of parallax for a comet in 1577. development of new ideas and techniques to search for dark Although many offered challenges to the orthodoxy of matter candidates, many of which are still being pursued Aristotelian cosmology, these attempts were not met without today (Sec. IX). resistance. The statue of Giordano Bruno in Campo de’ Fiori One of the main difficulties in reconstructing the history of in downtown Rome serves as a reminder of the dangers that dark matter is that the key developments took place in a were inherent in such departures from the strict Aristotelian continuously changing landscape of cosmology and particle world view embraced by the Catholic Church. It was at the physics, in which scientists were repeatedly forced to revise location of that statue that Bruno was burned at the stake in their theories and beliefs. The authors of this review are not 1600 by the Roman Inquisition, after being convicted on professional historians, but scientists writing for other scien- charges that included the holding of a heretical belief in the tists.