OAKLAND, Calif.--It's not hard to find monuments to technology in the Bay Area. Down in the valley, Google, Apple, and Facebook have each built their own cathedral-monastery, architectural showpieces that bound over the landscape. In the city itself, the Internet Archive is housed in an old church of Christian Science, its door gated by a marble Corinthian portico. And further downtown, where the land meets the bay, new obelisks even now are rising. Plenty of places will let you salute Fair Software and Tender-Hearted Hardware.

When the robot found the shipwreck, the humans controlling it must have been elated. The SS Central America, a paddle wheel steamboat, had gone down in a hurricane in 1857, loaded with gold from the California Gold Rush. For more than a century treasure seekers searched in vain. But in 1988, a robotic submersible operated by an outfit called the Columbus-America Discovery Group finally found the wreck roughly 200 miles off the Georgia coast. Lawsuits soon challenged Columbus-America's claim to the gold.

Humans have a tendency to rely on machines as a way of understanding ourselves. The mechanical world has long provided metaphors for how the human body works. "We've always had technological analogies to try to explain biology," said Chris Atkeson, a roboticist at Carnegie Mellon University. "One idea of how the brain worked was it's hydraulic. People described hydraulic clocks and the heart pumping blood.