American Scientist

Encyclopedia of Astronomy and Astrophysics. 4 vols. Paul Murdin, Editor-in-Chief. xx + 3,670 pp. Institute of Physics Publishing and Nature Publishing Group, 2001. $650.

I received my first set of encyclopedias when I was 10 years old. It was 1969. In those days, men wearing suits and ties would walk from door to door selling hairbrushes, Hoover vacuum cleaners and Veg-o-Matics. One day a salesman came to our house peddling the latest edition of the Encyclopedia Britannica. We already had a Hoover and a Veg-o-Matic, and the books seemed to promise so much more. It was an easy sale.

That was more than 30 years ago; itinerant salesmen dressed in their Sunday best are a thing of the past, and somehow it seems that bound encyclopedias are too. For one thing, there's all that information available for free on the World Wide Web. And knowledge changes so quickly these days that encyclopedias just don't age as well as they used to. Yet some very clever people decided to produce a new four-volume encyclopedia on astronomy and astrophysics, fields in which the annual flow of new data is measured in terabytes. What were they thinking?

Quite a bit, it turns out. In size and scope this encyclopedia represents an impressive labor. The four hefty volumes total more than 3,500 pages with about 2.5 million words and 2,000 illustrations; there are nearly 700 main articles by experts, with bibliographies; about 1,150 shorter articles (defining astronomical terms and objects, detailing space vehicles and missions, and describing observatories and institutes); and 650 short biographies. The main articles typically open with basic information accessible to novices and then include increasingly complex and theoretical material appropriate for advanced readers or professional astronomers. More than 600 people contributed, many of them prominent scientists in their respective fields: Leo Blitz has an article on interstellar molecular clouds, Paul Weissman writes about the Oort cloud, Joseph Silk weighs in on galaxy formation, Michael Turner tells us about the history of the universe, and Owen Gingerich recalls the place of Copernicus in astronomical history. Editing this was a massive undertaking, and Paul Murdin and his coeditors are to be commended on the result. Yet, is this the medium for their message?

I often use the Web in my work as a magazine editor in much the same way I use a reference book, so a side-by-side comparison seemed natural. As a test I looked up a couple of dozen subjects using my favorite search engine, Google, and compared the results with equivalent entries in the encyclopedia's index. In choosing the search subjects, I tried to anticipate the needs and interests of a broad range of encyclopedia users, from high-school students to professional astronomers. My test queries included some historical figures and events, but I concentrated on modern developments in the planetary sciences, astrophysics, cosmology and instrumentation.

The subject of my first query was dark energy, the mysterious force that appears to be accelerating the expansion of the universe. It's been a big story since 1998, and I expected it to challenge the encyclopedia's timeliness. That it did—I couldn't find an entry for it. The subject was covered to a certain extent under the heading of cosmological constant, but an uninformed reader—precisely the sort who might turn to an encyclopedia—might not think to look there, and so could walk away with nothing. The Web search, on the other hand, turned up a number of news reports and press releases that offered up popular-level introductions to the subject, providing some good leads on further topics to explore.

The encyclopedia fared much better on most of my other searches, which involved topics that were not so "newsy." The entry for spectrograph serves as a typical example. There are, in fact, several entries relating to the subject. An elementary introduction distinguishes the meanings of spectroscope, spectrograph, spectrometry and spectrometer, and also offers an essay on the role of spectroscopy in astronomy. More-advanced treatments cover the theory of spectrography and include instrument drawings and descriptions.

Search for spectrograph on the Web and you'll get a mixed salad of pages including commercial spectrographs for sale, technical reports on various instruments and abstracts that happen to mention the word. The information is useful, if it happens to be what you're looking for, but if you just want to learn something about the instrument and its use in astronomy, you have to wade through a lot of useless pages.

All of my searches followed that pattern: The Web did better on news-related items, whereas the encyclopedia presented high-quality information on what might be considered the fundamentals.

To be fair, the publishers have anticipated such a challenge. An online version of the encyclopedia www.ency-astro.com promises to keep up with the rapid pace of change with quarterly updates, and the site includes breaking news too. During a 24-hour free trial of the online encyclopedia, the main difference from the print version that I noted was that you get color images online, whereas most images in the print edition are in black and white. I expect many people will balk at spending $650 on books that have a limited shelf life, but I'm not sure they'll find the online version's annual subscription rate of $200 much more palatable.

I still have my old Encyclopedia Britannica set, now more than 30 years out of date, but I visit Britannica.com more often than I turn to the books, which I stopped using sometime in the 1980s. For that matter, the old Hoover conked out back in the 1980s too. The odd thing is, my mother still uses the very same Veg-o-Matic. Maybe an item's value shouldn't be measured by how long it lasts.—Michael Szpir