SAN JOSE MERCURY NEWS

Distance learning

There was a time when knowledge of breakthrough innovations was acquired through word-of-mouth. (''I hear some guy named Archimedes discovered water displacement in a bathtub.'' ''Oh really? What's a bathtub?'') But then came telegraphs, telephones, television, and now, thanks to computers and the Internet, telerobotics.

Telerobotics? No brainteaser here; the answer is to be found in the 17 essays that make up ''The Robot in the Garden: Telerobotics and Telepistemology in the Age of the Internet.'' Editor Ken Goldberg is an engineering professor at the University of California-Berkeley and founder of the Art, Technology, and Culture Colloquium and an artist of Internet exhibits.

His title refers to The Tele-Garden, an Internet site (http://telegarden.aec.at/) where users can interact with a robot and direct it to tend to a real garden in the Ars Electronica Museum in Austria. During the beta testing of this site, Goldberg received an e-mail challenging the site's authenticity. The Tele-Garden, he was told, could easily be a fake. Goldberg agreed, and this led him into a study of how knowledge is acquired over a distance.

Taking his cues from epistemology, the philosophical study of knowledge, Goldberg calls his new field of inquiry ''telepistemology.'' With the burgeoning spread of ''webcameras,'' and other means of viewing the action elsewhere 24/7, has also come a rapid growth in telerobotics -- robots controlled at a distance -- that enable remote viewers to become a part of the action. The ability to experience events across a distance as if you were present has been dubbed ''telepresence'' and it opens up enormous possibilities for the acquisition of knowledge. For example, citizens of Athens and Sparta might have watched Archimedes run naked through the streets of Syracuse in real time then gone back and placed objects of their own choice in bathtubs.

Telepresence, however, brings with it some serious baggage, including a high potential for deception. How do you know there's really a bathtub with water and a naked Greek man inside it and can you really know that the water was displaced and not Photoshopped? If your senses can't be trusted in cyberspace, what happens to the acquisition of ''knowledge'' should telepresence be telefiction?

Such questions prompted Goldberg to solicit these essays, which come up short on hard answers, but provide food for thought. Following an excellent introduction by Goldberg and an equally fine essay by culture critic Thomas Campanella on webcams, the rest of the commentaries are roughly grouped into three categories: philosophy; art, history and critical theory; and engineering, interface and system design.

There is also a postscript that features an essay written in 1945 byMaurice Merleau-Ponty in which he discusses the implications of cinema (then as new and expansive as today's webcams) for what was then a growing new field of Gestalt psychology.

Every essay in ''The Robot in the Garden'' is strong, and each writer is effective in presenting a point of view. But opinions grouped within the same category are contradictory. For example, in the philosophy section, UC-Berkeley professor Hubert Dreyfus makes a convincing case that the questions raised over knowledge acquired via telepresence echo the doubts raised in the 17th century by Rene Descartes, who argued that all knowledge mediated by the senses is questionable.

A professor from Australia, Jeff Malpas, counters that the only reliable knowledge is that which you acquire through your senses while experiencing an event first-hand. His point that telepresence is no substitute for being there seems well taken until you read Alvin Goldman, an epistemologist at the University of Arizona, who says that once the reliability of a source has been established, knowledge acquired from that source is as real any other. Getting knowledge from a telerobot need not be any less valid than learning someone's temperature using a thermometer, he maintains.

Not much gets resolved in all those contradictions, which is why my favorite essays in this collection are the ones that deal with the technology. Blake Hannaford, an engineering professor at the University of Washington, starts off with a good historical overview of telerobotic research.

UC-Berkeley computer scientists John Canny and Eric Paulos follow with proposals for the design of ''tele-embodied'' systems that would greatly improve interactions between humans and telerobots.

Judith Donath, from the Media Lab at MIT, weighs in on ''tele-identity'' and the problems that already make it difficult sometimes to distinguish robots from humans on the Internet. Can any of us, she wonders, ''know'' someone else based on their telepresence? Finally, there's Michael Idinopulos, another UC-Berkeley telerobotics expert, who meditates on the repercussions of interfaces that become too transparent.

''The Robot in the Garden'' certainly won't be the last word on telepistemology. Goldberg writes, ''As we race forward, throwing overboard the values that used to provide ballast, we struggle to maintain our hold on the slippery thing we call knowledge. Telepistemology may help us to stay afloat.''