Letters from the June 19, 2004, issue of Science News

Scan or scam?

Using laser technology that has an apparent resolution of only about half a centimeter is somewhat laughable (“Laser scanners map rock art,” SN: 4/3/04, p. 222: Laser scanners map rock art). I also wondered whether the “fresh coat of desert varnish” was an April fool joke. Actually, I really look forward to every new issue. You do a great job.

Fred Dombrose
Charlotte, N.C.

For images that weren’t three-dimensional, the equipment produced detailed, 1-megapixel images, on par with many digital cameras. The “fresh” coat of desert varnish was several thousand years’ of minerals deposited by the desert itself.—S. Perkins

Fish stories

“Hooking the Gullible” (SN: 4/24/04,p. 264: Hooking the Gullible) reminded me of the old quote: “A fishing lure is any combination of metal, plastic, wood, feathers, hair, or other manmade or natural material attached to a hook (or hooks) and designed to attract fishermen.” To wit: Decades ago, to impress an office associate who was a trout-fishing traditionalist as to how random were the criteria for successful lure designs, I concocted a device before his very eyes in about 5 minutes. The body was a remnant of a peel-off pencil eraser painted with Wite-Out, with hooks attached by a wire that also formed the loop for the line. That evening, I demonstrated the new design by landing two chain pickerel with it.

Marvin E. Kahn
Darnestown, Md.

Matching a lure’s color scheme to the prevailing prey takes too much thought, besides which, most prey is camouflaged. What I think about when choosing a color are flash, fluorescence, color intensity, and color combinations. For all humans know, bass have something in their genetic makeup that is a complete color catalog of everything they can eat. Therefore, a perch-colored Rapala becomes lunch, even if that bass never has seen, much less munched, a perch. The bass’ eyes and pea brain are geared toward color and contrast detection not to identify, but to detect. A pink worm will most times be more effective than a super-realistically colored worm. We may not always know exactly what a color looks like at the fish’s eye level, but fluorescence and flash are predictable and visually attractive.

Frank Manuele
Walden, N.Y.