Why we have not discovered dark matter: A theorist’s apology

The script begins with a welcoming address by Emily Pett, Associate Director for Strategic Partnerships, Grants, and Awards at Perimeter Institute. She introduces the public lecture series event held at the Mike Lazaridis Theatre of Ideas and acknowledges the Institute's mission to unite people in the quest for cosmic knowledge. The Institute, situated on traditional Anishinabe and Neutral peoples' territory, is celebrating its 25th year of fostering scientific dialogue. The audience is encouraged to engage on Twitter and a workshop on 'Dark Matter First Light' is highlighted. The speaker for the evening, theoretical physicist Philip Flip Tado, is introduced. Dr. Tado, an award-winning professor at the University of California Riverside, discusses dark matter's impact on the universe's structure and seeks to unravel its fundamental physics.

Dr. Flip Tado starts his lecture by engaging the audience with a show of hands regarding their knowledge of dark matter. He humorously presents an invisible picture to represent dark matter and then uses an artistic rendition to illustrate our position within a 'bubble' of dark matter in the Milky Way. Tado emphasizes the mystery of dark matter, which is invisible and undetectable by traditional senses, and likens our understanding to fish unaware of the water they live in. He discusses the scientific community's approach to understanding dark matter, referencing the various evidence from astronomy and cosmology that points to its existence.

The lecture continues with Dr. Tado discussing the evidence supporting the existence of dark matter, including its gravitational effects on galaxy motion, galaxy clusters, and the cosmic microwave background. He highlights the complementary nature of this evidence, which strengthens the case for dark matter. Tado also touches on the historical context of dark matter research, mentioning the contributions of astronomers like Fritz Zwicky and Vera Rubin. He emphasizes the interdisciplinary effort required to understand dark matter, involving both theoretical physics and astronomy.

Dr. Tado delves into the theoretical aspects of particle physics, describing the standard model as a mathematical framework that organizes our understanding of fundamental particles and forces. He explains the significance of the Higgs boson and its role in the standard model, as well as the challenges it presents, such as the question of its relatively light mass. The lecture also touches on the historical development of particle physics, including the Nobel Prize-winning electroweak theory, and the pursuit of the Higgs boson at the Large Hadron Collider.

The lecture explores the connection between theoretical models and the search for dark matter. Dr. Tado discusses the concept of weakly interacting massive particles (WIMPs) and how they were thought to be a prime candidate for dark matter. He explains how theoretical models, such as supersymmetry and extra dimensions, were used to predict the properties of dark matter and how these models were tested against astronomical observations. The talk also addresses the challenges faced when experimental results do not align with theoretical predictions.

Dr. Tado emphasizes the importance of creativity and diversity in theoretical physics, drawing an analogy between the search for dark matter and the need for diverse perspectives in scientific research. He discusses the 'missing talent' puzzle in physics and the importance of equity and diversity in academia. Tado argues that the field benefits from a wide range of backgrounds and experiences, as this diversity can lead to innovative ideas and approaches to complex problems.

In the concluding part of the lecture, Dr. Tado discusses the future of dark matter research and the role of theoretical physics in addressing fundamental questions about the universe. He highlights the importance of continued exploration and the potential for new discoveries, such as the use of gravitational waves to study the universe. Tado also stresses the value of theoretical models as tools for understanding and making predictions about the natural world, even as they evolve and adapt in response to new information.