Ron Voller - Hubble, Humason and the Big Bang: The Race to Uncover the Expanding Universe

Most people imagine astronomers as lone individuals silently looking through their telescopes night after night. Indeed, many of historys most famous scientists labored in solitude. By contrast, modern astronomy is a highly collaborative enterprise. Many of us work with teams of scientists from around the world. Indeed, today it is not uncommon for a paper in The Astrophysical Journal to feature tens or even hundreds of authors. The 2017 paper on the first electromagnetic detection of a gravitational wave event famously had several thousand authors.

Between these extremes is the special collaboration that occurs when two scientists team up to address a problem. In these partnerships, each individual provides his or her specific strengths to address the challenges that they face, often complementing areas where the other researcher may have less expertise. The dual-person team also allows theories and interpretations to be vetted prior to publication. The resulting conclusions represent the concurrence of both persons research methods and solutions. A two-author paper carries the implicit assumption that both contributed substantially to the research. Generally this is true. I have had the pleasure of being part of a scientific duo many times in my career, and I look back on these papers particularly fondly. They represent some of my best work as a professional astronomer.

Among renowned scientific duos, Edwin Hubble and Milton Humason rank at the top. Together, this unusual pairing of the famous scientist and the former janitor provided the conclusive observational evidence that the universe is expanding. The implications of this discovery could not be greater. An expanding universe must have had a beginning. This led inevitably to the Big Bang theory. Much of our modern understanding of the universe derives from the Hubble-Humason collaboration. While Hubble continues to be recognized for the telescope that bears his name and is seen by many as the most important astronomer of the 20th century, much of his best work would not have been possible without Humason, whose patience allowed him to collect data at Mount Wilson that perhaps no other person at the time was capable of obtaining.

While much has been written about each man individually, Ron Vollers fascinating book explores their unlikely collaboration as never before. He makes the convincing case that left to their own devices, neither man would likely have uncovered the evidence for the Big Bang. While others would eventually have stumbled on this evidence, the unique combination of their skills and the best telescope of their era accelerated our understanding of the universe by many years. The Hubble-Humason partnership epitomizes the power of the two-person scientific team to unlock some of natures biggest mysteries.

This book is timely for a number of reasons. Today, nearly a century after Hubble and Humasons revolutionary work, astronomy is in a golden age. Every day, new discoveries expand and reshape our understanding of the cosmos. These findings are a tribute to the creativity and ingenuity of scientific collaboration, and a crucially important validation of science itself.

As director of The Carnegie Observatories, I have the pleasure of working in the same historic building in Pasadena where Hubble and Humason carried out their important work. Almost every day, I enjoy seeing in our library a large photograph from February 1931 commemorating a talk given by Albert Einstein that was attended by many other famous astronomers. Several of these luminaries were selected to pose with Einstein in the portrait. Hubble towers above them, and directly by his side stands Humason. The message couldnt be clearer.

A full recounting of the partnership between Edwin Hubble and Milton Humason has been wanting, one that immerses us in the history that created them, that surrounded them, and that helped define the nature of their characters as men of science and the world. The fact that the discovery of the Big Bang experimentally has been linked so indelibly with Hubble, while not an accident of history, is certainly misleading for a number of reasons, first and foremost as it regards Humasons contribution to that legacy. Linking them inexorably to the discovery for all time is a central focus of this book and, it seems, a just and worthy cause.