Collider: The Search for the World’s Smallest Particles

Collider: The Search for the World’s Smallest Particles , Paul Halpern , Wiley, Hoboken, NJ, 2009. $27.95 (260 pp.). ISBN 978-0-470-28620-3

Theoretical physicist Paul Halpern is a prolific, award-winning author and a respected popularizer of science. In his latest book, Collider: The Search for the World’s Smallest Particles, Halpern offers the general reader a historical perspective on the development of particle physics in the 20th century and a peek into its future. The collider in the title refers to CERN’s Large Hadron Collider, a major international scientific facility located outside of Geneva, Switzerland.

Never have particle physicists felt as assured of achieving groundbreaking discoveries as with the onset of LHC operations. When Congress stopped funding the Superconducting Super Collider in 1993, US particle physicists, with strong support from the Department of Energy and NSF, joined the international scientific community in developing the LHC’s scientific program. The US LHC project was funded in 1995 with scientific goals similar to those that had been proposed for the SSC, namely, to find the long-sought Higgs boson and to discover new phenomena expected to augment the currently incomplete standard model of particle physics. The LHC is planning to restart operations soon, following an incident a year ago in which a faulty electrical connection between two of the accelerator’s superconducting magnets caused mechanical damage and helium to leak into the LHC’s tunnel (see Physics Today, October 2009, page 25 ).

The book jacket for Collider promises a “comprehensive guide to the theory, mechanics, and science behind experimental high-energy physics.” The book is not Richard Rhodes’s scholarly epic, The Making of the Atomic Bomb (Simon & Schuster, 1986), but it has the flavor of that work. It is quite chatty, interesting, and a fun read. Halpern has a captivating style that can keep the reader engaged and wanting more. Unfortunately, the book doesn’t provide much in the way of visual aids; more diagrams, pictures, and even simple equations would certainly have helped elucidate some of the material.

Additionally, the manuscript contains misstatements and imprecise remarks, which reflect poorly on the competence of and degree of scrutiny provided by the proofreaders and editors, and even on the author’s understanding of the subject matter. In many places, changes in wording would have yielded a far clearer picture, one without errors and confounding descriptions. For example, the book confuses “beam energy” with “energy in the center of mass,” is sloppy about distinguishing between mass and energy (and the meaning of E = mc ²) and about the scattering angles in Rutherford scattering, and appears to misconstrue the meaning of beam luminosity. If such errors are caught and removed in a second edition, or if explanatory pages of errata are contained in a subsequent printing of the book, I could recommend it with enthusiasm to high-school students or other nonscientists interested in learning about the origins of modern particle and astroparticle physics.

Finally, to paraphrase Carl Sagan, in science, it is the way of thinking that matters. From that perspective, it seems that Halpern does not fully appreciate the nature of experimental particle physics. At the end of the book, he bemoans the imminent demise of collider research not only because of its increasing costs but also due to the limited access students and researchers have to the field’s technical aspects, such as experience in the design, construction, and commissioning of scientific equipment. During the 1960s and 1970s, there was similar concern for the education of students and postdocs who chose to analyze bubble chamber pictures, and therefore did not develop many technical skills. Nevertheless, when new tools were eventually required, they were developed by those very same individuals, because they were physicists who asked searching questions and were able to devise different experiments; they were not automatons wedded to a specific methodology. The increasing cost of colliders is certainly an issue, but we can expect inventiveness as in the past, and new, clever means for complementary investigations. So I do not share Halpern’s gloomy outlook for particle physics.

Although I disagree with some of Halpern’s views and pedagogical approaches, I think the reader will find that Collider has much to recommend it. Unfortunately, its value has been undermined by careless editing that I hope will be corrected in a follow-up edition.