Science  16 Jul 1999:
Vol. 285, Issue 5426, pp. 295

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  1. COOL IMAGES: To Kill (and Paint) a Mockingbird

    Twenty paintings from John James Audubon's 1827 The Birds of America, along with masterpieces by Alexander Wilson, Elizabeth and John Gould, and 38 more 18th and 19th century ornithologist-artists are on virtual display at a Cornell University Library exhibit called Beautiful Birds. The art and science of bird studies developed in tandem during this period, particularly in the Americas, where the rush to discover (and name) new species lured ornithologists out into the wilderness to collect and paint specimens.

    The Cornell site guides visitors through different eras and techniques, and includes links to bird songs.

  2. NET NEWS: Search Engines Fall Short

    To find that one snippet of information hidden in the thicket of data on the Web, most users turn to search engines. But a survey of the 11 most widely used search engines, reported in last week's issue of Nature, suggests that these trailblazers are losing the scent. No single search engine, the study found, covered more than 16% of the Web's contents (see table).

    Computer scientists Steve Lawrence and C. Lee Giles of the NEC Research Institute in Princeton, New Jersey, first carried out a “census” of the Web's contents. By checking out what was behind 3.6 million randomly chosen IP numbers—the unique number for each Web address—the researchers calculated there to be about 3 million servers hosting 800 million pages. Next the duo ran 1050 queries on the 11 search engines and compared them to the results for Northern Light, which produced the most hits and, at 128 million pages in its index, covered about 16% of the Web. The other engines ranged from 15.5% to a measly 2.2% coverage.

    This situation won't last forever, Lawrence predicts. The “growth rate [of the Web] will presumably slow down, so the search engines should catch up,” he says. Meanwhile, the 11 engines combined cover about 42% of the Web, making software tools like MetaCrawler that harness together several search engines “the way to go” for exhaustive searches, says Lawrence.

    View this table:

    Bank of Iceland. A controversial plan for a private database of genomic and health data on the people of Iceland is the focus of this site, set up by two anthropologists. In addition to discussion forums on the social, scientific, and ethical issues raised by the deCode Project, Mapping the Icelandic Genome offers reams of background reading, including a list of 700 news articles.

    Telescope troubleshooting. Mysterious blobs and streaks in optical telescope images often result from mundane things such as a dusty lens, scattered starlight, or even a dead ladybug in an instrument's filter. This site, called “Observational Mishaps,” offers astronomers examples of faulty images and fixes.

  4. SITE VISIT: Dating Game

    Ever since chemist Willard Libby invented it after World War II, radiocarbon dating has been a boon to science. The technique has helped experts debunk the Shroud of Turin that supposedly covered Christ, for example (the cloth is only 650 years old), and date the 5300-year-old Ice Man found frozen in the Italian Alps in 1991. A wealth of information on this versatile test can be found at the Radiocarbon Web-info site.

    There's something here for everyone, from kids curious about how radiocarbon dating works (by calculating how long it would take carbon-14 in samples of plants or animals to have decayed to current levels) to archaeologists who need to know what can throw off a sample's date (like a nearby CO2-belching volcano). Web master Tom Higham of the Radiocarbon Lab at the University of Waikato in New Zealand wrote many of the 50-some pages himself, covering topics such as the method's history and how to decontaminate samples. An applications section leads to sites on dating the Dead Sea scrolls, reconstructing the ancient vegetation of the Americas, and much more. Other outside links include the world's 130 radiocarbon labs and a primer at Oxford University on how tree rings are used to calibrate dates.

  5. Science Online

    Commentaries in Science are often thought-provoking, and now you can add your own 2 cents online. This month Science Online launches dEbates, an electronic system for responding immediately to Editorials, Policy Forums, and Essays on Science and Society. E-mailed comments that contribute to the discussion will be posted within roughly 3 days. Look for dEbates links on the Editorial, Policy Forum, and Essay pages.

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