This Ideas Roadshow Collection includes the following 5 Ideas Roadshow Conversations which are based on in-depth filmed conversations with world-leading physicists plus a detailed preface highlighting the connections between the different books: I. Cosmological Conundrums - A conversation with Justin Khoury, Professor of Physics, University of Pennsylvania. This extensive conversation gives a window into the world of a practicing, theoretical physicist cosmologist, the often-considerable gap between formal scientific positions and personal scientific interests and examines a wide range of fascinating topics that his research covers such as the early universe, the Big Bang, dark matter, dark energy, Cosmic Microwave Background, the MOND (Modified Newtonian Dynamics) theory, and more. II. Astrophysical Wonders - A conversation with Scott Tremaine, Professor Emeritus of Astrophysics, Institute for Advanced Study. Topics that are part of this extensive conversation include the process of scientific discovery, in particular related to comets, Pluto, planetary rings, shepherding satellites, exoplanets, chaos theory and the formation, stability and uniqueness of our solar system. Further topics include galactic-scale astronomy, galaxy formation, dark matter, quasars, black holes, the large-scale structure of the universe and many outstanding open questions of contemporary astrophysics. III. A Universe of Particles: Cosmological Reflections - A conversation with Rocky Kolb, Professor of Astronomy and Astrophysics, University of Chicago. After an inspiring story of how Rocky Kolb became interested in science, this wide-ranging conversation covers topics such as the development of and his work on inflationary cosmology, the Standard Model of particle physics, dark matter, dark energy, Modified Newtonian Dynamics (MOND), the Large Hadron Collider, advice for high-school teachers to ignite a passion for learning in students, and more. IV. Inflated Expectations: A Cosmological Tale - A conversation with Paul Steinhardt, the Albert Einstein Professor of Science and Director of the Center for Theoretical Physics at Princeton University. He is one of the originators of the theory of cosmic inflation and has become one of its fiercest critics. This fascinating conversation covers topics such as Paul Steinhardt's scientific development, his formative experiences at Caltech including his encounters with Richard Feynman, his development and later scepticism of the theory of cosmic inflation, the response of the scientific community to the failure of this theory, his theory of cosmology, The Ekpyrotic Universe, and more. V. The Cyclic Universe - A conversation with Roger Penrose, co-recipient of the 2020 Nobel Prize in Physics and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford. Roger Penrose explores in detail the fundamental problem that is consistently being overlooked in modern cosmology, "Why did our universe begin in such a particular state of extremely low entropy?", his motivation to come up with his Conformal Cyclic Cosmology (CCC) theory and detailed insights into his groundbreaking research. Ideas Roadshow award-winning conversations present a wealth of candid insights from some of the world's leading experts, generated through a focused yet informal setting. Combining accessibility, substance and spontaneity, they are explicitly designed to give non-specialists a unique window into frontline research and scholarship that wouldn't otherwise be experienced through standard lectures and textbooks.