Reflecting on the Paris exposition of 1900, Henry Adams admitted to being overwhelmed by the new technologies on display. He was awed in particular by the electricity-generating dynamo. One wonders what he would make of the technologies described by Sonia Arrison in her new book "100 Plus."

"We are at the cusp of a revolution in medicine and biotechnology," Ms. Arrison announces, "that will radically increase not just our life spans but also, and more importantly, our health spans." This revolution will "change everything, from careers and relationships to family and faith."

Consider tissue engineering, in which human organs, grown from scratch or rebuilt in a laboratory, are transplanted into sick humans.

Scientists across the world, Ms. Arrison says, are working on engineering close to two dozen different human organs in the lab, including bladders, lungs and hearts. Progress is slow, and it might be decades before bioengineered organs are commonplace, but the trend-line is clear. The quest for longevity is an old one, of course, from Ponce de León's Floridian adventures to Benjamin Franklin's wondering whether he should have his body preserved in a cask of Madeira wine to "be recalled to life at any period, however distant." Ms. Arrison entertainingly chronicles efforts to conquer aging and death from antiquity to today. Food, sex, exercise and alchemy have all been employed to keep the grim reaper at bay. But technology offers the most plausible route, she says, noting that biology and computing are drawing ever closer together with the sequencing of the human genome.

What is more, technology heavyweights are paying attention, including Bill Gates (if he were a teenager today, Mr. Gates once said, he'd be "hacking biology") and Jeff Bezos ("atom by atom we'll assemble small machines that will enter cell walls and make repairs"). Larry Ellison, of Oracle, started a foundation more than a decade ago to support anti-aging research; the institution donates about $42 million a year.

Noting that similar worries have been raised whenever technology alters social conditions, Ms. Arrison argues that apocalyptic prophecies are unlikely to be realized. Increasing wealth and mankind's adaptability and ingenuity mean that as new problems emerge, new solutions will be forthcoming. "In looking at the trends of history," she says, "we can see that even when there are downsides to a particular wealth- or health-enhancing technology, the problem is often fixed once the population reaches a point where it feels secure in spending the resources to do so."

Ms. Arrison's sunny outlook is infectious, and surely mankind does have remarkable powers of problem-solving and adaptation. But one can't help wishing, a bit ahead of time, for some wise counsel from one of those 150-year-olds she envisions, who might be able to tell us whether all the effort and all the dreaming were worth it.