Books

Is a 500-Year Human Life Span Just Around the Corner?

With unprecedented leaps in human longevity over the last century, are drastically longer lives within our grasp?

Editor's note:The following is an excerpt from Jonathan Weiner's new book Long for This Worldwith the permission of Harper Collins.

Late August, late afternoon, cloudy-bright.

We’d taken a corner table at the Eagle, just inside the red door on Benet Street. From there, the tavern’s windows looked across to the tower of St. Benet’s Parish Church, the oldest tower in the town of Cambridge and the county of Cambridgeshire. The church’s foundation stones were laid almost a thousand years ago, when England was ruled by King Canute, son of the Viking King Sweyn Forkbeard, distant descendant of Gorm the Old.

A tavern stood across from that church tower in the year 1353, with beer for three gallons a penny -- with shops and markets up and down the street, then as now, and around the corner the spires of the University of Cambridge, pointing at the same cloudy English sky. During the reign of Queen Elizabeth the First, the tavern was called the Eagle and Child. Elizabethan scholars would have stared up at its gently swaying signboard and (gently swaying themselves) remembered the myth of Zeus, who swooped from the clouds in the shape of an eagle, caught a child named Ganymede, and flew him off to Mount Olympus to serve as the gods’ cupbearer, one of the immortals.

We’d been talking for an hour or two. The Eagle had been almost empty when we sat down. Now from the courtyard and the barrooms beyond we could hear more and more voices rising, glasses clinking. In the year 1940, in one of those barrooms, young pilots of the Royal Air Force who could not be sure they would come back placed chairs on tables, stood on the chairs, raised their cigarette lighters, and wrote their names on the ceiling with the soot of the flames. In another barroom, in the year 1953, two young biologists at the university used to meet over ale when they finished work at the Cavendish Laboratories, a few minutes’ stroll down the lane past the church. James Watson and Francis Crick were trying to solve the structure of DNA, and hoping (they were not yet quite sure) that they’d figured it out. “So,” Watson confesses in his memoir The Double Helix, “I felt a bit queasy when Francis went winging into the Eagle to shout that we had found the secret of life.”

The Eagle remembers the pilots, and Churchill’s praise: “Never in the field of human conflict was so much owed by so many to so few.” And in the DNA barroom, the present management has engraved a line from Watson’s memoir on the panes of the glass door: “I enjoyed Francis Crick’s words, even though they lacked the casual sense of understatement known to be the correct way to behave in Cambridge.”

Before the year 1500, when the College of Corpus Christi and the Blessed Virgin Mary, which is the nearest college of the university, built a chapel of its own, many of the school’s dons and scholars would have begun their days in the parish church and ended their days in the tavern.

In the church, the prayers of the ages: For this corruptible must put on incorruption, and this mortal must put on immortality. In the tavern, the toasts of the ages: May you enter heaven late! May you live a hundred years! May you always drink from a full glass! They prayed for long life in the pews and they proposed long life in the pub, being the same mortals from morning to night.

“When you start talkin’ about five-hundred-year humans” -- said Aubrey David Nicholas Jasper de Grey -- “five-hundred-year humans, or one-thousan’-year humans, most members of the general public get a li’l bit nervous.” Aubrey was enjoying his fourth pint of ale at the Eagle, with dinnertime still some distance away.

This was our farewell drink. I’d spent most of the summer in London, and quite a few hours in Cambridge, listening to Aubrey over pints of ale. I’d heard him predict five hundred years for us, I’d heard him give us a thousand years, he’d hinted about a million years. He’d foreseen the coming of this new age of man in fifty years, or even as swiftly as fifteen. Now, because this was goodbye, Aubrey was trying to summarize his views, and to convert me once and for all, and I couldn’t turn the pages of my notebook fast enough to keep up with him. I kept raising my hand to stop him while I scribbled, and while I scribbled he drank.

Tap, tap, tap went Aubrey’s glass against the table, according to the sober testimony of my voice recorder. I’d placed it on his side of the table, by the cascades of his enormously long brown beard. From there it picked up every word, slurred or not -- along with each groan and mortal screech of chair legs and barstools against floorboards, and the frequent moments when Aubrey refreshed his voice and set down his pint.

“I mean, you have to appreciate the scale of this,” Aubrey said. “It never leaves my mind.” Think of it, he said: one hundred thousand human beings die of the infirmities of old age every single day. “One hundred thousand lives! I’m at the spearhead of the most important endeavor humanity is engaged in. Not easy to do, even though I don’t often show it,” he said, looking off. His face was struck by the late cloudy light from the windows of the Eagle, like a gibbous moon, three parts bright and one part in shadow.

Tap.

At a table near ours, a few people from the university explained to a guest, “Cheers! It means, Here’s to your health.” Their guest returned with his own toast in a language that sounded Central European. It meant, To life! In 1940, the airmen of the RAF defended London and bombed Berlin. Now a sign on the wall warned “No Smoking” in English, French, Spanish, Japanese, and German. “I should probably expand on that. You know, cuz people occasionally ask me about it, you know, how I cope with the -- the responsibility, if you like,” Aubrey said, with a small, apologetic chuckle. “Basically I just feel that I’ve got to put things out of my mind and get on with it. I just don’t think about it. This is my fourth beer, you may have noticed.”

Pause. Tap.

“And that helps, quite honestly. I do not like to think about it.” Tap. Gravely he looked off again into the distance, toward the windows on Benet Street, stroking his beard. I had the feeling of watching a stage performance that I’d seen before. Aubrey had to be forgiven if he lost track of the speeches that he’d already made to me. He was talking with so many people around the world that he could hardly be expected to keep track of whichspeech he made when. But I felt sure he’d made this particular speech to mein another tavern with exactly the same lonely haunted stare into the distance. Was it here at the Eagle, over Abbot Ale? At the Tabard Inn, in Washington, over Foggy Bottom Ale? The Live & Let Live, in Cambridge, over Nethergate Umbel? My memory was getting a bit hazy. Somewhere before, he’d shown me this same look of agony, his secret anguish presented for my private viewing, with just the same half-turned head, looking aside and one-quarter down, the same phase of the moon. And watching him stare out the window, I felt sure that he had made the same speech in the same way with that same tilt of the head to many others by now. I had a sense of the crowd gathering around him.

Aubrey had stepped into the role that seems to open up again and again, the role of the prophet or sage who declares that we do not have to die, that we can be among the saved if we will follow him to safety. The same character in every age -- an immortal character who is reborn endlessly, who has probably appeared more than once right there in that very tavern, given its own longevity, and the power of our longings.

Friends of mine, distinguished biologists, were a bit shocked to hear that I was talking with Aubrey de Grey. One of them warned me that if I listened to Aubrey I would be making “a martyr out of a molehill.” But I didn’t see Aubrey as either of those things; and I didn’t think he was mad, either. Of course, he did drink. He admitted that himself. He had a long beard -- but if you were charitable, you could say he wore that as a badge of office, the way an old fashioned doctor would wear a white coat and a stethoscope. He really was highly intelligent, and he knew his field. He published papers with good people. He organized conferences, and respectable biologists came, and afterward some of them sat with him in the Eagle, too, listening and arguing. All in all, Aubrey was a remarkable phenomenon, a complicated mix of old and new, preposterous and plausible, practical and paradoxical, neither fish nor fowl. You could dismiss him with a laugh, but you would be wrong. In all these ways he was not unlike the field itself.

“This is lives we’re talking about! It’s people’s lives,” cried Aubrey now. “We’re talking about one hundred thousand people a day. I’m driven by everybody. I used to be driven by myself. Now I don’t think about myself, except that I’m making so much difference that it’s important I don’t get assassinated or fall under a truck.”

Tap.

“Ultimately the sheer numbers are what drive me now. I just have so much disgust for any excuses. The idea one could postulate utterly vapid sociological concerns as genuine challenges to saving thirty World Trade Centers a day -- I just don’t have any words to describe . . .”

I held up my hand and scribbled.

“I don’t do this anymore to extend my life span,” Aubrey said again. “Small sliver of my motivation. My motivation is: it’s going to be sooner, based on what I’m doing now. And I don’t give a damn whose lives. I don’t give a flying fuck whose. One way or another, someone’s going to benefit.”

Through the windows of the Eagle, I watched the clouds part again above the tower of St. Benet’s. The sun flared against the pub’s windowpanes with the tawny light of late August. Caught in those light shafts, Aubrey’s pale face and his long brown beard were lit from one side once more, now one half bright, the other half in shadow, the moon rushing through its phases. He said, “I mean, I think it’s inconceivable that people born even ten years ago will die of old age, in spite of our pitiful reluctance to hurry -- because serendipity will get us there in the end. It’s just a matter of what we can do to accelerate things.”

Our dates are brief, and therefore we admire what is old, as Shakespeare observes in one of his death-defying sonnets. We are brief, and therefore we admire a stone tower, a storied tavern, a Greek myth, an antique rippled windowpane, almost anything that seems to have more time than we do.

There was a time, not so long ago, when what we wanted to deal with our brevity was grace: grace to accept what we could not avoid, old age and death; courage to accept or to defy in the spirit what we could not change in the flesh. That was our condition from time immemorial. In every generation we worked toward grace. On every island and continent, we hoped for the best.

Now we live in a new time, with a somewhat different sense of time. Our life expectancies are increasing by about two years per decade, or about five hours per day, according to the standard estimates of scientists who study human life spans. That is to say, for every day we live now, we are given the gift of another five hours to live later on. While time runs out today, time pours in tomorrow. It is almost, but not quite, like the gift of an afterlife.

We find it hard to appreciate the scale and the suddenness of our success. In the Stone Age, most human babies died before they had reached the age of one or two. Few lived long enough to grow a single gray hair. The average life expectancy of Stone Age babies was probably not much more than twenty, although the evidence is scarce and the estimates are controversial (most of the science of human life span is controversial). When the Roman Empire was at its height, in the first century of the first millennium (a time when legionnaires patrolled Castle Hill, above the River Cam), Roman life expectancy was only a few years better: about twenty-five years. During the Middle Ages, in the first century of the second millennium, the era of the founding of some of the world’s first universities -- Bologna, Oxford, and Cambridge -- life expectancy was about thirty years. During the Renaissance, it was thirty-three years.

In our corner of the Eagle that afternoon, the prints that hung on the wall just above Aubrey’s head showed two jolly drinkers with tankards raised. Those gentlemen’s powdered wigs and red coats would place them in the time of King George the First, Second, or Third. Back then, the tavern on this spot was called not the Eagle but the Post House. Horse-drawn coaches came rumbling into the cobbled courtyard every day to deliver the mail. By the Eagle’s courtyard gate, you can still see the markers that guided in the coachmen -- the old stone posts. Life expectancy in Georgian days rose toward forty years in England, less in its thirteen colonies. “When we see men grow old and die at a certain time one after another, from century to century, we laugh at the elixir that promises to prolong life to a thousand years,” said Samuel Johnson. In reality, men and women were growing older and dying just a bit later each century; but by so little that Johnson was right to laugh.

By 1900, in the most developed countries of the world, including England and the United States, life expectancy had crept up to forty-seven years. That’s all that a baby born in 1900 could expect. But if those babies survived and thrived and became parents themselves, their own children could expect to live longer; and their children could expect to live longer yet. By the end of the twentieth century, babies could expect about seventy-six years. Throughout the twentieth century, life expectancy changed so fast that for the first time in history, people became aware of it as a phenomenon that was extending their life spans during their own lifetimes. During the twentieth century we gained almost thirty years, or about as much time as our species had gained before in the whole struggle of existence.

In other words, this is a good time to be a mortal. Life expectancy today is roughly eighty years for anyone in the world’s developed countries. And life expectancy is still improving, which is why each day we live now we are given the gift of more time down the road. It’s as if we’re all driving on a highway that is still being built, and the roadbuilders are adding to it at a good rate. Our bodies haven’t changed. We haven’t evolved. A few generations is too brief a time for our life spans to have gained thirty years through evolution. It’s only that our circumstances have gotten more comfortable. A field mouse in the wild lives about one year. The same mouse in the safety of a cage lives about three years. With our farms and supermarkets and reservoirs and thermostats, we have done for ourselves what we have done for a pet mouse. We have tripled the life expectancy that our ancestors enjoyed or suffered in the wild.

To be clear: Life expectancy is the average age that babies born in any given generation or any particular year can expect to reach. Maximum life span is the longest that any member of a species is known to have attained. It is by the measure of life expectancy that our success has been most spectacular, so far, because we have done so well at helping babies and little children survive the dangers of their first years. But we are also doing better at helping people in their later years. Certainly, there have been fortunate people throughout history -- those who were protected by great genes, wealth, power, luck -- who have lived to a ripe old age. The ancients also had ancients. Among the pharaohs, Ramses the Second is believed by Egyptologists to have lived beyond the age of ninety, possibly to one hundred. Among the ancient Hebrews, when King David composed his psalms in Jerusalem, about three thousand years ago, our maximum life was thought to be about eighty years. David wrote, “The days of our years are threescore years and ten, and if by reason of strength they be fourscore years, yet is their strength labor and sorrow; for it is soon cut off, and we fly away.”

Those lines from the Psalms were translated for King James the First by a committee of scholars in Cambridge in the first years of the 1600s. Some of the king’s translators probably enjoyed a pint at the Eagle and Child. The longest-lived among them was a mild, cheerful, good-natured man named Laurence Chaderton. Chaderton could still read without spectacles when he was very old -- one hundred years old, assuming his own count of the days of his years is reliable. He died on November 13, 1640, at the age of 103.

So there were happy specimens of old age in ages past. But now that our lives are so comfortable and secure that most of us reach eighty, more and more outliers have the chance to live well beyond eighty, and beyond the ages of Ramses and Chaderton. The world’s record holder to date, Jeanne Calment, of Arles, France, lived to the age of 122 years and four months. The length of her days was 44,724. That is about the age that God promised Adam and Eve after evicting them from the Garden: “My spirit will not contend in man forever, for he is mortal; his days will be a hundred and twenty years.”

The study of longevity is now in an almost feverish state. Twenty years ago, not many biologists worked on the problem. The field was small. It seemed old. You might say the science of eternal youth was looking and feeling its age. Efforts to extend the human life span in any serious, deliberate way had gotten nowhere since the studies of the ancient Greeks and Babylonians; since the tomb-builders and tomb-robbers of Egypt; since the glory days of the Taoist deep breathers, extreme dieters, and sexual athletes of China (“He who is able to have coitus several tens of times in a single day and night without allowing his essence to escape will be cured of all maladies . . .”). But today the science of longevity is growing fast. Once more it is turbulent, and painfully confused. It feels young again. The faces of the biologists who argue at international meetings about where we are, where we are going, and what we can or should do when we arrive, really are getting younger, because many new people are joining the field.

Specialists in this field call themselves gerontologists. The word comes from the Greek root geron, which means old man, but that suggests a focus that is misleadingly narrow. While it’s true that the problems that limit our life span are normally most visible and cruel when we are old, gerontologists care about much more than the last years of life. They want to understand the whole span. Pediatricians treat the young. Geriatricians treat the old. Gerontologists try to understand why our bodies change from youth to age, why we age at all -- why we are mortal. The problem of longevity is a deep problem because to understand it well enough to do anything fundamental about it, you first have to answer the questions: What makes us mortal? Why do we die? Why do we get frail year by year and ever more likely to die? When does the decline start -- at forty? At thirty? When sperm meets egg? And where does it start -- in the cells that compose the fabric of our tissues? In the way the organs talk, or fail to talk, to each other? What is aging? This is one of the hardest problems in biology. It is even harder than explaining consciousness. No one has managed to explain consciousness yet, either, but for some time we’ve had the source narrowed to a zone above the neck.

As gerontologists do begin to locate and explore the sources of mortality, many of them feel an incredible excitement. It’s true, of course, that every mortal reaches the end of the road eventually -- somewhere around the age of one hundred twenty, even supercentenarians seem to come up against a wall, and most gerontologists accept that wall as our limit. But they have hopes that they can help more of us reach it, and alleviate some of the suffering of old age along the way. As we approach some kind of limit now, it seems likely to most gerontologists that to go much further with either our average life expectancy or our maximum life span we would require a breakthrough in their science, in their understanding of the wellsprings of mortality. Only if they can figure out what aging is and what to do to change its rate will human life span take another big jump. Most gerontologists do not expect to see that breakthrough in their lifetimes. One group of conservative, well-respected gerontologists has proposed that our goal should be to add another seven good years to the human span. A few of the most enthusiastic people in the field have begun to argue for much more. If they are right, then our descendants in another few generations may expect to live as long as Moses, who is said to have lived 120 years; Noah, who lived 950 years; or Methuselah, the oldest man in the Bible: “And all the days of Methuselah were nine hundred sixty and nine years: and he died.”

Aubrey de Grey thinks there is no limit. He is convinced that we can double or triple our life span again and again, and so onward and upward. We can engineer as long a life span as we like, “even life for evermore” (Psalm 133). That’s hardly the majority view in gerontology. On the other hand, the field is so splintered and spiky right now that it’s hard to find a majority view. Gerontologists can’t agree on a way to measure aging, or what they mean by aging. Because so much of the action takes place in the United Kingdom and the United States, they can’t even agree on how to spell the problem under discussion: aging or ageing. They fight over definitions of longevity, health, life expectancy, life span, maximum life span. But even in this overheated moment, Aubrey is the most fervent of them all.

Aubrey David Nicholas Jasper de Grey was born in London. His mother was a bohemian artist in Chelsea. She gave him his extraordinary name and some of his extraordinarily great expectations. (He never met his father.) He attended the University of Cambridge at the college of Trinity Hall, where he learned to drink beer, write computer code, and punt on the Cam, which is one of the favorite sports of students in Cambridge. He stayed in town after graduation, writing code.

Aubrey is six feet tall and medievally thin and pale, in spite of all the ale. When he stands up, his beard reaches a surprising distance toward his waist. When he sits down, it pools in his lap. “I find it useful to look unusual,” he told me once. He looks like Methuselah before the Flood. Father Time before his hair turned gray. Timothy Leary Unbound. The beard never changes in length because Aubrey is always worrying it away at the edges, twining strands of it around his long pale fingers, even twisting the whole thing into a rope and pressing it to his shoulder when he sups his soup or blows his nose. He is a compulsive debater for his cause, and the beard is one of his weapons. “When I am stroking it like this you know you are all right,” he says, “but when I begin to twist it like this you know I am about to pounce.” He’s made it his personal mission to demonize the bad old days when the science of gerontology was forlorn and we were all trapped and confined in a mortal existence; and to herald the days soon to come, when we will live a thousand years or more.

In a student town like Cambridge, with his beard, jeans, and T-shirt, whizzing around on his old bicycle, or striding through the campus with his faintly belligerent lope, or punting on the Cam, it would be hard to guess his age just by looking at him. In fact, he was born in 1963. That makes him one of the last babies of the great baby boom, or one of the first babies of the next.

In 1990 he met an older woman, an American geneticist named Adelaide Carpenter. She was born in 1944, in the dark of the war years. They met at a wild party that he threw in Cambridge. At the time he was a young man who liked to throw wild parties; she was an established biologist who’d made her reputation early and had lost her way in her career. She joined Aubrey in Cambridge. They married, and soon afterward, Aubrey became fascinated by biology and began his quest for immortality.

Aubrey thinks of aging as a medical problem. Since we all have this problem and it is invariably fatal, he believes we should hit it as hard as we can. He’s convinced that every one of us will join the quest as soon as we realize that there are no technical obstacles to the cure for aging that can’t be overcome, at least in principle. Our bodies are molecular machines. As they run they make mistakes, or give off toxic wastes they can’t quite manage to get rid of. The mistakes are tiny. The wastes are submicroscopic. If we are lucky and enterprising we may find that the conquest of aging may require nothing more than a series of cleanup projects. Our bodies are like houses and cars. What we have to do (Aubrey puts this more positively: all we have to do) is keep up with the cleaning and repairs.

If we looked after our bodies properly we would stay healthy year after year after year, until we finally misjudged our step off a curb and ran into that truck. We would no longer die of our years. That is, we’d be no more likely to die at the age of ninety or 290 than we had been at the age of twenty. We would achieve a kind of practical immortality. Aubrey prefers the term “the engineering of negligible senescence,” the creation of human bodies that hardly age at all.

It’s a very British approach, in a way, consonant with a certain brisk stiff-upper-lip approach to immortality. In matters of the heart and mind and spirit, avoid muddle. In matters of the body, avoid rubbish. In some ways, you might even say, what Aubrey is proposing to do for the body is what civilization has accomplished for public health at large. Life expectancy stayed so low for most of human history because so many babies died at birth, along with their mothers. Improvements in housing, heating, farming, public health, the construction of sewage systems, the washing of hands in hospitals, and, in the twentieth century, the discovery of antibiotics -- all these things together transformed our life expectancy. Public hygiene in Cambridge was horrible back in 1353. Aubrey proposes we clean up our bodies the way we have learned to clean up our cities and towns.

From time to time that summer I’d reminded Aubrey that I was listening as a reporter, not a disciple, that I was talking to many other gerontologists, trying to get the whole picture. Aubrey said brilliant and incisive things about what he called his Strategies for the Engineering of Negligible Senescense, or SENS. He’d published his manifesto, “Time to Talk SENS,” in the Annals of the New York Academy of Sciences, in 2002, with half a dozen coauthors, including some highly respected scientists. And Aubrey had published many papers since -- he was incredibly prolific, he seemed to write as fast as he talked -- and often those papers were coauthored by specialists at the top of their fields. It seemed clear to me that Aubrey was a gifted amateur and provocateur. He’d pulled together a great store of arguments that the conquest of aging is at least a good goal, more than half a century after Watson and Crick, and that as a goal it makes sense. But he was also riding out into combat against almost everyone in gerontology. And in fact soon after that summer almost everyone in gerontology really did wheel around on Aubrey in one of the most spectacular, almost theological controversies in science in recent memory. Twenty-eight of the field’s leaders signed a broadside in which they tried, in effect, to excommunicate Aubrey de Grey. “Aging research is a discipline that is only just emerging from a reputation for charlatanry,” they wrote. What a shame to see journals and scientific meetings give space “to empty fantasies of immortality.”

The goal of a few more good years or even good decades of life might be reasonable, but Aubrey de Grey’s scribblings about SENS, with his talk of five hundred years, a thousand years, a cure for aging, were like essays on Aladdin’s lamp. “Only a few people didn’t sign,” says the gerontologist Jan Vijg, one of the abstainers. Another abstainer was Judith Campisi. Vijg and Campisi are both distinguished gerontologists with a special interest in cancer. They think the conquest of aging is as reasonable a goal as the conquest of cancer, diabetes, atherosclerosis, Alzheimer’s, or any of the other killers that rise up to get us in old age. If we have a War on Cancer, why not a War on Aging?

Once, talking with Campisi about all the controversies in gerontology, I threw up my hands. Maybe I shouldn’t write about gerontology at all, I said. It’s too confusing. It’s too soon! “Well,” she said, “it’s not solved. You’re writing about a problem that is not solved. I mean, if you want to write about a problem that’s solved then you can write about smallpox.” However, she said, if you want to talk about how a field has been muddled by human longings and blunderings for thousands of years, and has matured, then this is the problem to look at, because this is arguably the oldest problem in science, and it has suddenly come of age. “And if it matures even to the point where the field of cancer is now,” she said, “if it can get to the point where cancer is now, it has the potential to change the course of human history.”

Although I often reminded Aubrey that I wasn’t riding out to the jousts with him, he seemed to forget my warnings from one meeting to the next. On that last day at the Eagle, he talked as if we were both believers; and now that I was leaving he was talking extra-fast, trying to sum up the situation and the needs of the campaign.

With more and more hubbub around us and more and more ale inside him, Aubrey really was getting hard to follow. “A v’iety -- va’iety -- variety of opinions . . .” Both his hands fiddled rapidly with his apocalyptic beard and mustachios, although I could tell that he was trying to speak slowly.

When Aubrey was in his cups, I’d noticed, his words came out thick and bushy, as if his tongue were cramped by his mouth, or his lips were too big. His voice itself stayed clear and reedy as a clarinet, his arguments remained as clever as ever, but something seemed to happen to the words. Somewhere in the tangles of his beard, they got brushy and muffled and indefinably squiggly, like a glimpse of figures, a line of horsemen, advancing through the brambles and the trees of a forest.

He wanted me to understand the difficult political situation he faced. Not only did he make the public nervous. He terrified most of his senior colleagues. They thought he was a menace. They were afraid that he would turn politicians and taxpayers against them. “And the main reason tha’ I’m fabulously dangerous,” Aubrey said, “is that I talk about these long life spans. Which is going to scare peo’le off doing anything. They’re goin’ to say, ‘Oh, no, no, no -- let’s not fund any gerontology at all!’ ” Tap, tap, tap . . . “I’m no’ a diplomat, you know,” Aubrey said, and paused for a swallow.

Tap!

“A political animal, but no diplomat.”

Pause. Tap!

“I don’ find it easy to compromise. I find it easier to find solutions -- to fin’ killer punches.” Aubrey mimed a roundhouse right at the air -- ka-pow! -- and laughed a roguish laugh, grinning at me eye to eye, conspirator to conspirator, as if the two of us really were about to witness the defeat of old age and the conquest of death, the cosmic victories that the world has longed for ever since Adam and Eve lost Paradise.

Pause. Clonk!

“Fucking aitch!” Aubrey cried. He’d just drained his glass and glanced at his watch. “It’s already quarter past five! I mean, it’s fine, you know, it’s fine -- this is valuable time. I’m scheduled to be at home for dinner at half past six -- so what I ought to do is try to delay that. Let me nip over to the bar -- they have a phone at the bar -- and see if I can -- ”

From a stool at the far end of the bar, an old codger kept staring over at our table. I thought that same man -- or someone just like him -- had stared that way before from that same bar stool, with just that same ruddy, wrecked, xenophobic amusement, that leer from the Mad Hatter’s Tea Party. (Was it the Eagle? The Live & Let Live?)

Aubrey’s talk was toxic and intoxicating. Here was the dream of the ages. And yet, in some ways, what an awful moment to be dreaming about it, with so many mortal humans alive already; with so much of the living world in ashes around us, or near the flames.

“Depend upon it, sir, when a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully,” said Dr. Johnson. And when we are told that the sentence of death under which we all live may be lifted, it makes our minds expand wonderfully, as if we have lived all our lives in a state of compression, increasing concentration, like a bird that is being lifted slowly on a finger toward the roof of its cage, or like a human body that is compressing with age, drawn down by gravity. It is strange and novel even to consider for a moment the possibility of negligible senescence; to consider that aging really might have a cure -- a cure that we would desire, that is, not the one cure that the world has known since the beginning of time, which is death.

Of course, some of the gerontologists were so excited by the possibilities that they were only partly sober. They went weaving around the hard consonants and the insoluble problems that loomed up in the middle of their sentences the way a drinker emerging from the Eagle will sometimes go dodging around the lampposts and the parking meters.

This is where the science of mortality can take you. You can sit in the House of Watson and Crick, more than half a century past the Secret of Life, and pop down the rabbit hole, where every twist and turn is Wonderland, where each view is curiouser and curiouser, until you wonder how in the world you will ever get out. You can cross over the river and descend into depths where mortals have wandered for a thousand thousand years, trying to solve the riddle, wanting to know for sure, longing to climb back up and see the stars.

Jonathan Weiner is one of the most distinguished popular-science writers in the country: his books have won the Pulitzer Prize, the National Book Critics Circle Award, and the Los Angeles Times Book Prize.