Michael Turner has been one of the leading pioneers in the emerging field of particle-astrophysics: the effort to understand the large scale properties of our universe by exploring the fundamental microphysics that ultimately governed the earliest moments of the big bang. It has been an area in which most of my own research has been focused, so it is not surprising that Michael I became on and off research collaborators starting about 40 years ago. In 1995 Michael and I published a paper arguing that 70% of the energy of the universe must reside in empty space if the data at the time were to be self-consistent. Three years later two groups confirmed our prediction, and were awarded the Nobel Prize in 2011 for that discovery. Michael later coined the term “dark energy” to describe this completely mysterious quantity.

Michael is not only a leading scientist, he is also a leading expositor of astrophysics, having written one of the seminal books about the physics of the early universe, and he is frequently sought out by journalists to comment on current results, and by academic audiences for his popular lectures. He has a wry sense of humor, and over his more than 40 years of scientific research he has been involved in many of the key developments that have shaped astrophysics. He has also helped direct the national research effort itself, having been a deputy director of the National Science Foundation, and a former president of the American Physical Society.

Mike and I sat down for a long overdue discussion of his own perspectives on the field. We discussed his personal history, motivations, and challenges as a young scientist, and then went on to discuss many of the key areas of progress in cosmology over the past 40 years, including some puzzles which remain today, and about which one often reads in the popular press. For anyone interested in cosmology, our discussion will shed a great deal of light on which problems are real, and which are not, and also give a new perspective for how far we have come over the last half century in unraveling many of the mysteries of the universe.

As always, an ad-free video version of this podcast is also available to paid Critical Mass subscribers. Your subscriptions support the non-profit Origins Project Foundation, which produces the podcast. The audio version is available free on the Critical Mass site and on all podcast sites, and the video version will also be available on the Origins Project Youtube.