It is difficult not to expect great things when a terrific science fiction writer teams up with a legendary one. Fortunately, Stephen Baxter and Arthur C. Clarke exceed those expectations with The Light of Other Days.

Their extraordinary collaboration is a sociological treatise cloaked in the trappings of traditional SF. While the book is driven by a revolutionary technology, Clarke and Baxter's examination of its impact has as much to do with us as the society it changes.

When industrialist Hiram Patterson introduces stable wormhole technology, he envisions it as the beginning of the next information revolution, "a link down which we can send signals -- beating light itself."

Curzon creates a process that enlarges wormholes enough to transmit images rather than simple data packets. These wormhole transmitters -- dubbed "WormCams" -- are deployed as news gathering and espionage tools.

When the technology hits the public domain, it changes the very nature of society. Suddenly, anyone can spy on their friends, neighbors, lovers and children.

When Curzon learns how to move WormCams through time as well as space, life only gets more complicated.

With the full sweep of personal and historical pasts open to first-hand observation, comfortable illusions shatter. People discover that many of their cherished heroes and iconic figures had feet of clay or never truly existed.

Under the WormCam's gaze, Robin Hood fades away "into legend and confabulation, leaving not a trace of historical truth," and people learn "the depressing truths surrounding Elvis Presley, O.J. Simpson and even the deaths of the Kennedys."

The WormCam revolution isn't the only shock hitting the human psyche, either. An enormous comet is on a collision course with the Earth, creating a mood of resigned nihilism as people face a seemingly non-existent future and a suddenly unreliable past.

Clarke and Baxter leave no sacred cow unslaughtered when chronicling the WormCam's influence.

The government spies on enemies of the state. Private citizens monitor the police.

Psychologists battle their patients' self-denial by confronting them with details of their pasts, and astronomers visit other worlds from the privacy of their labs.

The response to the WormCam's panoptic gaze takes several forms. Some retreat into darkness and silence to hide from the public eye.

Others carry the technology -- and its attendant loss of privacy -- to the extreme, implanting WormCam generators in their heads and joining group minds.

This is nothing new. "Premise . . . extrapolation" is a bedrock SF principle, with such distinguished practitioners as Olaf Stapledon and George Orwell.

What is striking about The Light of Other Days is the novel's uncommon breadth and scope. Clarke and Baxter examine every aspect of their one technological change while still weaving an entertaining and at times troubling story.

Ultimately, The Light of Other Days is thinly veiled social commentary. We may not like to admit it, but our illusions of privacy are almost as tenuous as those shattered by the WormCam.

As governments and businesses record more and more of our actions, nobody lives an unexamined life. Each of us is pushed, filed, stamped, indexed, briefed, debriefed, and numbered every day.

For the right price, any life is an open book. And while we can't debunk the past as unambiguously as Clarke and Baxter's fictional characters do, every new historical perspective we consider renders its pivotal figures suspect if not invalid.

We may not like it when Clarke and Baxter shine The Light of Other Days on us. On the other hand, when that light comes from the authorial equivalent of a binary star, it's rewarding to catch some narrative rays.