The Matter of Everything: How Curiosity, Physics and Improbable Experiments Changed the World
by Suzie Sheehy
Alfred A. Knopf, 2023

Near the end of the Victorian era, after witnessing enormous progress in the areas of electromagnetism, thermodynamics and statistical mechanics, many physicists complacently believed there were few great physics problems left to tackle. However, cracks in what is now referred to as classical physics soon appeared, and Professor Suzie Sheehy's new book, The Matter of Everything, begins with one of those cracks - Wilhelm Röntgen’s discovery of x-rays in 1895.

While investigating cathode ray tubes, Röntgen happened to notice a phosphorescent glow on a screen across the lab that only appeared while the cathode ray tube was in operation. Not knowing the source of this phenomenon, he dubbed this new form of radiation x-rays. He quickly determined that these x-rays easily penetrated many materials and famously took an x-ray picture of his wife’s hand. Doctors, quickly realizing the utility of this new technology, adopted it within a year to identify bone fractures. However, many fundamental questions remained, including the composition of these x-rays.

Beginning with the discovery of x-rays, Sheehy, an experimental physicist who leads research groups at the University of Oxford and the University of Melbourne, continues her tour of particle physics through a series of experiments that led to the discoveries of the electron (1897), atomic nucleus (1911), and measurement of the electric charge (1923). By the end of the first third of the book the theory that the atom is the smallest piece of matter is in tatters and the remaining chapters of the book describe the fascinating experiments physicists designed to better understand the particles that make up an atom.

Sheehy clearly describes how physicists first observed matter breaking naturally, such as collisions between cosmic rays and atoms or by the decay of radioactive elements. However, experiments based on these phenomena were subject to chance and physicists wanted to wield a tool that could break apart matter in a more controlled and predictable way. Starting with John Cockcroft and Ernest Walton's particle accelerator that artificially split the atom in 1932, Sheehy leads the reader through the exciting race to develop ever more powerful and complex particle accelerators required to unlock the mysteries of subatomic particles.

Not content with merely overviewing the history of particle physics, Sheehy also describes how scientists did not always understand how new technologies developed during the course of their experiments would eventually affect society. One such example is the invention of the cyclotron by Ernest Lawrence in the early 1930's, which enabled scientists to direct beams of high-speed protons that collided with a target to create new and perviously unknown radioactive isotopes. Some of these radioisotopes were found to be effective in diagnosing and treating some cancers and thyroid disease. In contrast, as part of the Manhattan Project during World War II, Lawrence adapted his cyclotron into a mass spectrometer that would separate uranium-238 from uranium-235 - a major milestone to fueling the first atomic bomb.The realization that some of these discoveries led to applications that could either enhance or destroy life was something that scientists have had to grapple with ever since.

Sheehy also dispels the myth of the lone scientist making important discoveries in isolation. many of the experiments she included in her book, she devotes time to relatively unknown lab assistants, graduates students, and engineers who made critical contributions, demonstrating that even a hundred years ago, physics was a collaborative science whose advances relied on the talent and dedication of colleagues with a wide range of expertises and deep knowledge of their predecessors’ work.

The book's climatic experiment focuses on how scientists built and used the Large Hadron Collider at CERN to eventually confirm the existence of the Higg's boson in 2012. Having interned at CERN, Sheehy provides a unique perspective in describing the excitement and importance surrounding this event, which many consider to be the completion of the Standard Model used to describe the fundamental particles of matter. Although readers may still be baffled by the mysteries of particles physics after reading this book, they will certainly understand the Herculean efforts needed to discover subatomic particles and how these discoveries often led to technologies that affect our everyday lives.

Michael Janezic holds a PhD in Electrical Engineering from the University of Colorado at Boulder and is a metrologist and R&D engineer living in Denver, Colorado.