Beauty In The Eyes Of The Beholder

ELEGANT SOLUTIONS: Ten Beautiful Experiments in Chemistry, by Philip Ball, Royal Society of Chemistry, 2005, 212 pages, $39.95, 19.95 (ISBN 978-0-85404-674-7)

"Beauty is truth, truth beauty' that is all ye know on earth, and all ye need to know." Those are the final two lines of Keats's poem "Ode on a Grecian Urn." If that's really all ye need to know, then all experiments that yield truth are beautiful, and ye shouldn't waste your time trying to assess relative beauty. But people do it anyway, despite Keats.

A few years ago, C&EN published a list of the 10 "most beautiful experiments in chemistry," along with 15 runners-up (C&EN, Aug. 25, 2003, page 27). They were chosen from nominations submitted by American Chemical Society members, in response to a challenge from then-C&EN editor-in-chief Madeleine Jacobs, with the selection made by a panel of eminent chemists and historians of chemistry. Independently, around the same time, noted science writer Philip Ball was invited by the Royal Society of Chemistry to come up with his list. Ball's book "Elegant Solutions: Ten Beautiful Experiments in Chemistry" is the outcome of that project.

Ball's stated goal is not so much to achieve a definitive list as it is to highlight the importance of experiment to the historical development of the chemical sciences. He places a particular emphasis on "the gap that sometimes exists between the popular notion of how [the experiments] happened and what they meant, and (as far as it can be discerned at all) the historical reality." Ball is largely successful in that effort, although he doesn't always respect his disclaimer about the possibility of determining "historical reality."

For example, his chapter on Louis Pasteur draws heavily on the work of historian Gerald L. Geison, an unquestionably valuable counterpoint to the traditional accounts of Pasteur's life and work. But Geison's account has in turn been challenged, by critics as diverse as Chemistry Nobel Laureate Max Perutz and science sociologist Bruno Latour. Calling it "the real story," as Ball does, may be a bit of overreaction. Nonetheless, both chemists and nonchemists will find plenty of entertaining and informative material in this attractive and well-written book.

Ball further hopes his work will stimulate discussion, because "there is nothing like a list to provoke comment and dissent," he writes. I'm more than willing to provide some dissent—not so much about the particular choices he made, but rather on the whole idea of ranking experiments as more or less beautiful. Both Ball and the C&EN panel acknowledge that identifying standards of beauty that might attract broad, let alone universal, agreement is problematic. In fact, the two lists are far from identical.

Ball did consider the C&EN list, which appeared while his work was in progress, but in the end included only three of C&EN's top 10 and two of the runners-up: Pasteur's manual separation of enantiomeric tartrate crystals, which was first on the C&EN list; Neil Bartlett's preparation of the first xenon compound; Pierre and Marie Curie's isolation of radium; Henry Cavendish's production of water from its component elements; and Harold Urey and Stanley Miller's production of amino acids by zapping a model prebiotic atmosphere.

Four more of Ball's selections include two from the realm of nuclear chemistry: Ernest Rutherford's identification of α -particles as helium ions and Glenn T. Seaborg's generation of transuranium elements; and two from organic synthesis: Robert B. Woodward's vitamin B-12 and Leo A. Paquette's dodecahedrane. For the 10th item, read on.

While none of these choices is objectionable as a beautiful experiment, neither the lists themselves nor the similarities and differences between them offer much insight into what criteria—in particular, what aesthetic criteria—might be used to evaluate beauty. The subtitles for each of Ball's chapters suggest specific characteristics of beauty, but most of them are not very helpful. They include a pair of apparent opposites: "detail" for Cavendish and "simplicity" for Pasteur. There are a couple that don't stand out as obvious properties of beauty, such as "patience" for the Curies and "simplemindedness" for Bartlett. And there is at least one, "elegance" for Rutherford, that stands as much in want of definition as "beauty" itself.

Indeed, several of the C&EN panelists pointedly eschewed any aesthetic evaluation in favor of historic importance. According to Arnold Thackray of the Chemical Heritage Foundation, "By beautiful, we mean holding profound significance to us today." While Ball questions that conflation of concepts, noting that "there is no real reason why we should demand that a beautiful experiment also be an important one," he acknowledges that all of his chosen examples do pass the significance test. It would be interesting to see which, if any, experiments these pundits consider significant but not beautiful; perhaps that could point to some absolute criteria for defining beauty. Ball does observe that William Perkin's synthesis of mauve (ranked fifth in C&EN) was messy, inelegant, and accidental to boot, but he lets it stand as beautiful (though not in his top 10) because it produced a beautiful outcome—the purple dye itself.

Another issue, which receives little attention in either list, is the question of what counts as chemistry. Ball's 10th selection—Johann Baptista van Helmont's 17th-century "demonstration" that the increase of weight of a growing tree comes from the water used to moisten it, not the earth in which it is grown—is included as a very early illustration of the power of quantitative measurement. But is it a good example of a chemical experiment? (It also reached an erroneous conclusion: The weight increase comes mainly from the air.)

Conversely, if I were making my own list of beautiful experiments in chemistry, which it should be clear by now I would do only with the greatest reluctance, I would definitely include the Matthew Meselson-Franklin Stahl experiment that determined the mechanism of DNA replication by isotopic labeling. That work has been called "the most beautiful experiment in biology." For an excellent account, see the eponymous book by the late historian of chemistry Larry Holmes. The Meselson-Stahl experiment would surely get very high marks on any of the aesthetic criteria offered (elegance and simplicity), as well as that of significance. Does it not qualify as chemistry? For me, it does.

Refocusing on significance allows me to point out that one unfortunate consequence of these lists is the complete absence of anything of recent vintage. Only the two syntheses (B-12 and dodecahedrane) from Ball's list, and nothing at all from the full C&EN list, are less than 50 years old; the majority (21 out of 30) in the combined lists are pre-20th century. I would wager that any chemist could offer at least a few examples of newer work that rivals any of the chosen ones for elegance, but apparently nobody did so. Clearly the latest experiments have not yet withstood the test of time, but this absence may well reflect unconscious preferences at least as much as any explicit appeal to historical significance as a standard for beauty.

Psychologist Norbert Schwarz recently described in the journal Daedalus some experiments that show subjects are more likely to find beauty in a familiar object. His findings may suggest that the selections in these lists just represent the most often told stories of our chemical heritage, the best efforts to justify them on aesthetic grounds notwithstanding. Schwarz further observes that judgments of truth also depend heavily on familiarity. It looks like Keats was right all along.

Jay A. Labinger is an organometallic chemist and administrator of the Beckman Institute at California Institute of Technology.