The HP researchers do it by putting an object inside a dome that's fitted with a camera, scores of light bulbs, and a laptop computer to control it. A separate laptop runs a program to create a polynomial texture map (PTM) of the captured images, letting the researchers then change the lighting and surface characteristics.

The second technology was 3-D computer tomography, based on X-ray gear from X-Tek weighing nearly 8 tons. But unlike medical X-rays, these are real-time and digital, taking super-thin slices through an object and then recreating them into a 3-D image that can be manipulated. One result: The tomography not only showed new details of the gearing and teeth but also uncovered inscriptions never before seen.

Based on these results, the researchers discovered the following:

* The device was built between 150 and 100 B.C., somewhat earlier than previously thought. The shipwreck took place about 65 B.C. The date is significant, as is the assumption (based on some circumstantial evidence) that the ship, traveling a busy sea route, was heading to Rome from Rhodes, where one of the greatest of Greek astronomers, Hipparchus, lived and worked from about 140 to 120 B.C. Researchers speculate that he or one of this students could have influenced the design, and possibly the building, of part of the mechanism.

* The pin-and-slot gearing, as mentioned above, which creates an anomalous motion for the moon, simulating visually the mathematics created by Hipparchus to account for moon's observed, irregular orbit around the Earth.