Instant replay

Time and space are frontiers.

Automakers know this better than philosophers. That's why they link the desire to go fast and conquer distance to the vehicle they are selling. With the start of the NFL season, we're in for replays of car commercials.

Everyone accepts that TV ads play fast and loose with the laws of physics. We expect the message to bend time and space.

Sport utility vehicles (SUVs) no longer just ride the open road. The road itself changes from desert, to savannah, to mountain, to seashore with the turn of the steering wheel (and computer graphics). To avoid traffic, SUVs use skyscrapers as passing lanes. In one 4x4, switch on the ignition and you create the view outside your windshield.

Science writer Eric Niiler (page 14) introduces us to the Spray, a new class of AUV (autonomous underwater vehicle). Only oceanographers and the US Navy are interested in owning one. Rather than the open road, it conquers the sea.

The cruise missile look-alike lacks the romance of Kon-Tiki, Thor Heyerdahl's replica of a Peruvian transpacific raft from ages ago. And despite a complement of high-tech instruments, its propulsion system is the same. The AUV travels by hitching a ride on ocean currents. Wings and shifting ballast allow it to bob deep, 3,280 feet deep, then surface and roll over to beam data to satellites about water temperature, depth, salinity, and chemical properties.

From Oregon to Baja, from Los Angeles to Hawaii, like a perpetual-motion machine, the Spray continuously, effortlessly, precisely, and economically, traverses the immeasurable expanse of the sea.

Scientists will construct more accurate images of the marine environment. I can't wait for the replay.

(c) Copyright 1999. The Christian Science Publishing Society