A couple of months ago, the journal Nature published a study showing that mice that ingested a substance found in red wine demonstrated remarkable longevity. There is, so far, no evidence that the substance, resveratrol, has a similar effect on humans. Nonetheless, there has been a rush on the product; health food store owners say the stuff is flying off the shelves.

According to The Wall Street Journal, one of the researchers who originated the study, David Sinclair, began taking the supplements three years ago. And those of us who enjoy red wine have popped a cork or two in celebration of this latest news of its health effects.

Ponce de Leon, your quest continues. De Leon's search for the fountain of youth met a bitter end. In 1521, on his second trip to Florida in search of the magical fountain, he and his party were accosted by arrow-wielding Indians. De Leon was shot and later died of his wounds.

Folly and vanity meeting their just come-uppance? Maybe. But we may be, in fact, almost certainly are, on the cusp of a revolution in longevity. Those of us under the age of 70 right now will not regain youth, but we may very well extend our healthy lives decades beyond what was ever possible before. Whether this will be, on the whole, a good or bad thing for society is an open question. But it is around the corner.

It is far more than tipsy mice. The scientific world is abuzz with life-extending technologies and techniques -- some proven, others on the drawing board. Ray Kurzweil, winner of the 1999 National Medal of Technology, inductee into the Patent Office's Inventors' Hall of Fame and self-described futurist, offers tantalizing if somewhat freaky glimpses into the next 25 years of medical advances.

He reports, in "Fantastic Voyage: Live Long Enough to Live Forever," that the National Institutes of Health has funded research for a microscopic probe that would that would be inserted into a patient and would detect and treat precancerous and malignant tumors of the esophagus, stomach and colon. Kurzweil expects "nanobots" (blood-cell-sized robots built molecule by molecule) to perform a host of functions inside the body within the next 25 years.

"Nano-engineered blood-borne devices that deliver hormones such as insulin have been demonstrated in animals. Similar systems could precisely deliver dopamine to the brain for Parkinson's patients, provide blood-clotting factors for patients with hemophilia, and deliver cancer drugs directly to tumor sites."

In addition to all of this, scientists combining the disciplines of biology and artificial intelligence are developing technology that could one day replace whole human systems (like digestion) with improved biological/machine hybrids. The notion that human and machine are different spheres may change as we increasingly inject machines into our bodies and manipulate our cells. We may even be able to enhance intelligence. Work on gene therapy may yield the ability to turn gene expressions on and off -- which could affect everything from genetic diseases to the aging process itself.

Kurzweil may be a little crazy -- at one point he predicts human life spans of up to 5,000 years -- but let's assume that he's onto something. Let's stipulate that for those wealthy enough to take advantage of it (i.e., most Americans), science will make it possible for people -- say, your children and mine -- to live 200 years.

What would that mean? Let's see, Social Security benefits for 135 years? Medicare for the same period? Prescription nanobots for a century? Assuming that people will remain healthy and working for decades and decades (which is what the futurists predict), would the economy expand due to the continued productivity of well-trained people, or sink under the weight of the extra elderly? (Not all of those doddering around at the age of 140 are going to be on the tennis courts.)

The entire concept of family life would have to change. What would happen to the already high divorce rate if people had to spend the better part of two centuries together? How about military service? Would young men and women who could otherwise expect to live to such astounding ages be willing to risk dying at 20 or 25?

Worth pondering. Of course, if al Qaeda gets the bomb, all bets are off.