Stellar Alchemy: The Celestial Origin of Atoms , Michel Cassé (translated from French by Stephen Lyle) Cambridge U. Press, New York, 2003. $30.00 (242 pp.). ISBN 0-521-82182-7
Many of us like to reflect on our childhood and family history. The search for origins covers not only human sensibility but also astronomical pursuits. In fact, “origins” is one of NASA’s main themes and the title of one of its programs. In Stellar Alchemy: The Celestial Origin of Atoms, French astronomer Michel Cassé tells in his native language (translated by Stephen Lyle) some of the fascinating stories about how the elements in each of us came to be.
The lightest elements—including hydrogen (and its deuterium isotope), helium, lithium, beryllium, and boron—were formed in the first few hundred seconds or so after the Big Bang, an interval immortalized in Steven Weinberg’s book The First Three Minutes: A Modern View of the Origin of the Universe (Basic Books, 1977). Heavier elements, up to and including iron, were synthesized in stars. Elements heavier than iron come from fusion processes, called nucleosynthesis, that take place in supernovae, exceedingly violent events in our universe’s history.
Cassé tells how the ideas of nuclear origins were put together. He even tells a personal story about his asking William Fowler, who shared in a Nobel Prize for his work on the origin of the elements, how he had linked up with Fred Hoyle to figure out basic paths for nucleosynthesis. Hoyle had found the fundamental idea of how to bridge an instability gap with beryllium to form carbon. Cassé describes how the work wound up in the fundamental paper B2FH, which stands for Margaret Burbidge, Geoffrey Burbidge, Fowler, and Hoyle. The paper, which shows the variety of paths needed for the formation of elements, appeared in Reviews of Modern Physics in 1957.
Deuterium is the only isotope that is uniquely formed in the period just after the Big Bang. Thus deuterium abundance reveals initial conditions because, unlike helium, for example, which is a common product of stars, it is not created in the subsequent eons. Cassé acknowledges the importance of determining the deuterium abundance, but he relegates it to his first lengthy, discursive appendix in the book. He writes that “deuterium holds the key to the mystery, but it is difficult to measure.” My own work in the field deals with cosmic deuterium. Most recently, Jayaram Changalur, Donald Lubowich, and I tried again, without immediate success, to detect deuterium’s fundamental spin-flip line at a 92-cm wavelength using the new Giant Meterwave Radio Telescope outside Pune, India. But values of the deuterium abundance from UV spectra and from radio observations of deuterated molecules, which need chemical interpretation, have elucidated light-element formation from this primordial nucleosynthesis.
Stellar Alchemy is for the general reader, although some parts of the text and some diagrams are complex. The author does not hesitate to give equations for fusion and decay processes. I think it is strange and rather off-putting to begin each chapter with a boldfaced set of vocabulary words and definitions. Chapter 1 begins with 18 such definitions; chapter 3, with 24.
I found the language in the book forced and stilted, as though the translator was literally rendering flowery French in a style to which English speakers are unaccustomed. John J. Cowan, who reviewed the book for Nature (25 March 2004, p. 369), concludes that “Cassé’s writing style, flowery and poetic and full of historical references, makes even the more technical material accessible to the general reader.” So I guess someone likes it—but I don’t. My dictionary gives a definition of “interpellate” as interrupting a European parliamentary debate, but I still don’t know what “interpellated by the telescope” means in Cassé’s book.
I also wish that Cassé, his translator, or editors had spelled “Kirchhoff” correctly by adding the second “h” in the name. Furthermore, the French version of the book came out in 2000, before the results of the Wilkinson Microwave Anisotropy Probe; the English version should have been updated to include them. The probe results show that the type of matter that is the subject of this book makes up only about 4% of the contents of the universe, with another 30% or so being dark matter and the remaining 66% in the form of an unknown called “dark energy.”
Other updating in the book should have included the name James Webb Space Telescope , which was mentioned only under its previous name, Next Generation Space Telescope . The current name has been around since 2002. Some results from the European Space Agency’s INTEGRAL gamma-ray telescope, whose 2002 launch is mentioned, should also have been covered in the book. Such omissions make one wonder what else has happened recently in the field. Also, in preparing an English edition, the author or editors should have included other international researchers in the footnotes and additions, not merely the names of French astronomers who work in the field.
In summary, the field of nucleosynthesis is very important, and it is inherently interesting to see how the elements in our universe formed. If you are willing to wade through the unwieldy prose in Stellar Alchemy, you will find a wealth of information about the atoms we are made of.
