AMHERST, Mass. -- If a picture is worth a thousand words, then Jonathon Keats figures a picture can also span a thousand years.

Keats, a San Francisco writer and self-described experimental philosopher and conceptual artist, has designed a "millennium camera" that he intends to mount in a churchless steeple on a college campus and chronicle climate change by taking a 1,000-year exposure of a western Massachusetts mountain range.

If it seems far-fetched, consider that some of Keats' previous endeavours include selling tracts of real estate in the theoretical extra dimensions of space-time; opening a photosynthetic restaurant that serves gourmet sunlight to plants; choreographing honeybees; copyrighting his own mind to give his "intellectual property" a 70-year post-life extension; and, controversially, joining in a bid to genetically engineer God.

Even at his quirkiest, Keats notes he always has a serious message to deliver, and in the case of the millennium camera -- a cylindrical device small and light enough to hold in one hand but hopefully durable enough to survive the centuries -- it's encouraging people to think beyond their own human lifespan to what geologists call deep time, the lengthy periods in which the world changes on a grand scale.

"We need to find a way to think in deep time if we are to responsibly make use of the technologies we have," he says. "So the camera is intended, in a sense, as a mental prosthesis, as a way of creating some sort of a feedback loop in deep time, where setting up the camera now, looking out into the far future, allows for people who are alive in the far future to see the decisions we made through the effect that they had."

But will it work?

Even Keats can't say for sure. Nor is he certain humans will be around in 3015. Nor, assuming they are, that someone will know to retrieve the camera and open it.

A thousand years is, after all, a long time. In 1015, the Norman conquest of England was still more than 50 years away, the first crusade was more than 80 years away, and Columbus would not reach the New World for another 477 years.

The camera, Keats explains, is very simple, so simple that nothing mechanically should fail. "Which of course is the wrong thing to say, because then it will," he quickly adds.

It begins as the old science fair standby, the pinhole camera, which allows light to enter through a tiny aperture. But since pinhole cameras aren't designed to last a thousand years, Keats made his of copper because of its resistance to corrosion. The pinhole he pierced through a rugged 24-karat gold plate.

To capture the exposure, Keats adapted a Renaissance art technique by using rose madder, a sturdy, organic-based oil paint, applied directly to the copper in the back of the camera. Digital photography was impractical, and he ruled out using film because it would deteriorate too quickly and besides, there's always the chance by 3015 that society will revert to another dark age, without photochemical processing skills.

That image will be of the Holyoke Range, a modest but picturesque mountain chain that scientists believe has existed for 200 million years. What a denizen of the 31st century would see is not a before-and-after image, not what today we might call time-lapse photography, but rather one picture depicting a millennium of change.

For example, if the now heavily forested area were to gradually turn to grasslands, the trees, Keats predicts, will linger on the photograph as ghostly reminders of a prior period, set against the bolder outline of the more recent landscape.

Later this spring, Keats will ascend a harrowing set of wooden stairs inside the dusty steeple, position the camera and open its shutter, beginning what he believes will be history's longest exposure. He hasn't sought a patent for the device, which he estimates costs about $100 in raw materials to build, saying he wants others to copy it and place their own millennium cameras strategically around the world.

"I'm well overstating the case for these cameras," he concedes. "I realize (it) may seem like a supreme act of egotism. It's probably also an extreme act of naivety on my part. But I think you just have to give it a try."