In 1917, Private Hudson cut an unimpressive figure on the Western Front. He was small but wiry in build and by his own account, five feet four inches tall. Overloaded with his full complement of equipment, he struggled to clamber in and out of the trenches, even when the German guns weren’t trained on him and his pals.
On his first day on the front lines of the Great War, he had a nearly lethal mishap with a hand grenade. Standing in the safety of his own trenches, he and a small team of men were practicing hurling the devices far enough away to avoid shrapnel injuries.
The seventeen-year-old pulled out the pin and hurled the small metal pineapple as hard as he could. But it strayed off course, colliding with the top of the parapet wall and rebounding. It fell at his feet with the fuse inside burning down, counting off the seconds before it reached the explosive. There was a moment of panic before he and the rest of the bombing party scattered into the zigzag maze of the trenches, safely out of the way of the blast.
Stumbling across the shell holes of the Western Front and fumbling the occasional explosive device, the young James Hudson was nevertheless at the peak of his biological fitness.
Physiologically he would never be better than he was in that war. Damage suffered by his body through disease, accident, or the wear and tear of everyday living was addressed promptly and definitively.
The stem cells of his body were capable of stunning feats of regeneration; his immune system was robust; his body boasted huge physiological reserves. He could run faster, fight harder, and survive longer in the face of adversity than at just about any other time in his life. But he was already in his second decade of life and about to enter his third. And the process of aging would soon begin to gain traction.
The changes were at first imperceptible to the young private; they would have been measurable only in the laboratory by the most discriminating tests. Later that would change.
But Private James Hudson was a born survivor in every sense. He went over the top in the terrible battles of Mons, Arras, and later Ypres, staying alive against incredible odds. He also escaped the sweeping pandemic of Spanish flu that followed the Great War—a disease that claimed the lives of up to a hundred million worldwide.
Throughout his life, he continued to defy every expectation, living in three different centuries, watching a world transform beyond all recognition. And in the final years of his life, after more than a century of adventures and near misses, he finally found himself admitted to Mount Vernon Hospital, under the care of a medical team whose ranks I had just joined as a junior doctor.
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WHEN MOUNT VERNON HOSPITAL was built, in the middle of the nineteenth century, it was tuberculosis that stood as the great unmet challenge. It was a disease well described but poorly understood. Physicians could do little more than observe the consumptive horror of the infection as it took hold in lungs and spread to hearts, bones, muscles, and brains.
Mount Vernon specialized in its treatment. Built on the top of a hill, boasting wards with open balconies, it represented the cutting edge in Victorian tuberculosis therapy: essentially little more than a plan to expose patients to large volumes of fresh air.
Over its life, the hospital was repurposed more than once to meet the changing health-care needs of the population, as science and technology continued to redefine the fight against death and disease. It received the casualties of both world wars, becoming a full-fledged general hospital with an accident-and-emergency unit during the Second World War. Eventually, with the rationalization of health care in London and its surrounds, it lost its A&E department and became a “cold site” for the rehabilitation of elderly patients and the treatment of cancer. By the time I arrived, the hospital was over a century old, and it seemed fitting that in its twilight years, part of its raison d’être had become the care of the elderly.
Arriving fresh from nearly three years of acute medicine, with nights spent answering crash calls and pounding down corridors, it looked to me at first like the medical equivalent of limbo. A maze of small roads ran from the nineteenth-century buildings at the core to more modern units at the periphery. These aside, the site didn’t look as though it had changed much in the last hundred years.
The elderly-care rehabilitation unit was housed in a two-story prefabricated building, one that had been built at some time as a temporary measure but had since acquired a more permanent role. It was a place that received patients transferred from bigger general hospitals with more urgent pressures on their beds. The job of this essential—but essentially forgotten—corner of the National Health Service was to restore its patients to something of their former glory in the hope of getting them home once more.
The nights were quiet, and the job offered a break from the cut and thrust of intensive care and A&E, a chance, I thought, to focus on making preparations for my dreaded postgraduate exams.
In the evenings when I was on call, I would tour the wards just before midnight, scribbling the odd prescription, checking on one or two patients whom we were worried about before turning in. There was a side room on a disused ward with a hospital bed and plastic-covered pillows where you could put your head down with the reasonable expectation that you’d get some sleep.
The practice of elderly care at first felt very alien. As a former physics student, I was always looking for a way to reduce the problems I faced on the wards to something simpler, for systems that would collapse neatly into a few lines of equation and a physiological principle. But here medicine was far less algorithmic. There were, you rapidly came to realize, no quick fixes or easy answers to the medical problems that accompanied advanced age.
Part of what I had liked about astrophysics was the abstraction and the simplicity of the systems under study, systems so invariant in property that you could ask questions of bewildering complexity and have a reasonable expectation of getting decent answers.
In medicine it was the other way around. The human body appeared so unfathomable that we could only ever hope to answer the very simplest questions about the people whom we treated. We did stuff largely because it worked. While statistical methods often told us that our therapies were doing some good, we weren’t always able to explain why.
The field of anesthesia, with its emphasis on the integrated physiology of the human body and its attempts to explain acute changes at the level of first principle, was about as close to the reductionist approach of physics as I was ever going to get. And in the practice of trauma too, one was usually dealing with insults to physiologies otherwise uncomplicated by disease: a single, albeit massive, perturbation in an otherwise stable system. To some extent, all of this had felt vaguely familiar.
But when it came to the care of the elderly, the challenge became extreme. Here the underlying physiology of aged patients appeared to have been eroded, leaving them with less in the way of reserves, forever teetering on the brink of instability. Superimposed upon this were layers of chronic illnesses and side effects caused by dozens of drugs—many of which had undesirable interactions.
On top of all of this were considerations about the proper shape of an individual’s life: the state of their home, the strength of their circle of family and friends. For the elderly, the true benefit of every intervention had to be understood and weighed carefully against the considerable risks it presented. The physiology of these individuals was fragile and unforgiving.
Having ever known only acute medicine with all its urgency, the rehabilitation of the elderly was like learning the rules again from scratch. The biology of the younger patients I had gotten used to looking after was less nuanced and certainly far more robust.
As heroic as the trauma calls had appeared, they were in comparison like a goal-line scramble in a game of football: urgent and played out in seconds but always with the possibility that you might recover from your mistakes right up until the last instant.
Being a doctor specializing in the care of the elderly was much more like playing chess. A single poorly considered decision could prove catastrophic. Things happened slowly and in small moves. Sometimes the advance of a pawn was all that was needed. Sometimes retreat was acceptable—even necessary.
There are many stereotypes concerning old age, but I quickly learned that people grow more, rather than less, different from one another as time passes.
The rehab unit was built on two levels with perhaps thirty inpatient beds upstairs, divided between a ward to the south for the women and one to the north for the men. In the third bed from the door on the men’s side was Mr. Hudson, who had by this point reached the remarkable age of 103 in 2001. Now frail and afflicted with pneumonia, he was nevertheless sharp in mind and spirit. But the fact of his survival was perhaps less surprising to him than it was to us, his caregivers. For if there was one trick that James Hudson had learned in over a century of living, it was how to beat the odds.
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WHILE THE TWENTIETH CENTURY brought lifesaving innovations, it also gave rise to an array of increasingly violent ways to destroy ourselves and each other.
On February 12, 1898, a gentleman by the name of Henry Lindfield became the first recorded fatality from an automobile accident when he lost control of his two-seater and smashed into a tree outside of Purley. He had been driving downhill at the heady rate of 17 miles per hour.
Almost exactly a month later, James Hudson was born in a mews house in London close to Paddington Station. Although the house was within spitting distance of St. Mary’s Hospital, he was delivered at home, to a coachman and his wife, at a time when more than one in every ten newborn infants died at or shortly after birth.
He arrived in the world at the end of the nineteenth century, before highways or anything that resembled modern medicine, before the Wright brothers or Einstein’s great theories, at a time when Everest stood unclimbed, hearts were considered inoperable, and the maps of the world still boasted a vast uncharted continent of snow and ice to the south.
In the year of his birth, London was a city of cobbled streets and horse-drawn carriages. There was no ambulance service, welfare state, or National Health Service. Health care was something that only those of means could afford. Everybody else depended upon simple charity.
In a time before vaccination and antibiotic therapy, infectious disease was the leading cause of death. As the twentieth century approached, a child could, on average, expect little more than forty-five years of life. Around two out of every ten children born in that time were dead before the age of five. Nearly a third did not survive beyond twenty-five years. But that was not to be James’s fate.
Young Master Hudson left school at the age of fourteen. A bright and determined boy, he took up an apprenticeship in a dentist’s office in Tonbridge, hoping that he might one day gain entry to a medical school.
The Great War intervened—and Hudson bore witness to the terrifying efficiency with which mechanized society could destroy lives. But none of this broke either him or his stride. A year after World War I ended, he enrolled at Guy’s Hospital as a student of dentistry, and by 1928 he had his own dental practice.
Working within a hospital as a dental surgeon, Hudson began to notice an increase in the number of facial injuries and fractured jaws as a result of automobile accidents. He noted too that with his dental training and knowledge of the relevant anatomy, he was better equipped to deal with such patients than most general surgeons were.
He and several of his colleagues campaigned for the establishment of a new specialty—one that embraced dentistry and surgery in a single field, one specifically for injuries and operable diseases of the head and neck. This became the field of maxillofacial surgery. The boy who had started life in an apartment above a block of stables at the end of the nineteenth century became a consultant surgeon and one of the founders of a new surgical specialty.
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A LIFETIME LATER—AND NEARLY SIXTY YEARS since the birth of the National Health Service—I work my way around the ward from patient to patient, pushing the trolley of notes as I go. From the end of the bed, James Hudson appears frail. Tucked up in a chair with a blanket on his lap, he is thin and bespectacled, with white hair. The sagging of his features represents the disappearance of elastin, a protein that gives skin its youthful appearance. The lines of skin cells that have marched forward over so many decades continue to do so, only these days they are slightly less well made.
The fibers of his muscles too have changed, shrinking back, losing much of their youthful bulk. Their “cut,” the lines of definition that demarcate each muscle group clearly, has faded, thanks to a decrease in his levels of testosterone. And so too has the testosterone. The same apparent weariness of his body’s production line that is responsible for the changes in his skin has affected every system.
His spoken words are clear but noticeably less forceful than those of his younger visitors. The muscles that shape his voice, like those of his skeleton, have become weaker with time. The vocal cords cannot be held so consistently in position. They waver now in the same way that the muscles of his arm might if he were to lift a heavy weight. And the lungful of air that he expels in order to make those sounds is also smaller. Now that the recoil of his lungs is less powerful—like his skin, their elasticity too has been eroded—breathing out is more of an effort. The capacity of his lungs themselves has shrunk.
The evidence of Mr. Hudson’s great age goes beyond that which I can see and hear from the end of the bed. His biochemistry is deranged. His kidneys are less impressive: less capable of filtering the volumes of blood that course through them, more vulnerable to insult. The toxins and drugs that they are supposed to remove are cleared more slowly these days.
His heart beats with less force, empties smaller volumes with every beat. The electrocardiogram, which traces the spread of electricity through that vital organ, shows the occasional missed beat.
When he rises from his chair, he cannot pull himself up to his full height. The weakened bones of his spinal column have over the years given way to the forces generated by imperfect posture. The spine itself curls gently forward now, causing a permanent stoop.
When—with assistance—he gets to his feet, you cannot help but worry. The muscles of postural control, those that keep him upright, are less capable now. They labor under the control of the brain, which is unconsciously and perpetually making corrections to keep him on his feet. But that foreman too is less competent than it once was.
The intricate system of accelerometry in his inner ear—that which in youth and health can tell an Olympic figure skater when to emerge from a pirouette—is now prone to playing cruel jokes, occasionally providing illusions of motion when it is absent, leaving him unsteady. And the bones on which his flesh and muscle are hung are less dense, more prone to fracture when exposed to sudden force.
This is the physiology of great age, and the frailty that accompanies it is undeniable. But for all of the above, at 103 Mr. Hudson continues much as he must have done for most of his life. He is the oldest member of his golf course and a man who, until a month ago, still drove a car.
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IT IS ENTROPY THAT WE ARE up against here. Entropy is that property, common to all systems alive or dead, that sees them tend from a state of order to one of chaos. And once the processes of renewal and replenishment that maintain us in our youth begin to run down, we are left open to its ravages.
You can think of the biomolecules that comprise the cells and tissues of your body as though they were thousands of trillions of spinning tops arranged on a vast tabletop. In their initial state, they all stand neatly ordered—upright, spinning fast, and resilient to perturbation. But gradually, as they begin to spin down, they slow and become more unsteady.
Those tops can be respun and prevented from falling over, with a whip. Or those teetering on the brink of catastrophe can be removed completely and replaced with a freshly spun top. Whipping and replacing the spinning tops are processes analogous to the repair and regeneration of biomolecules. It is this perpetual input of energy to the biological system that temporarily staves off the consequences of entropy.
In youth, the process of entropy is held in check by the body’s intrinsic system of repair and regeneration—a system, if you like, that is constantly replacing many trillions of molecules and whipping them into shape. But just as a child eventually gets bored with the toy, so the body eventually begins to abandon the processes of repair and regeneration.
Unabated, the entropy of the biomolecules of which the body is composed manifests itself as the process that we experience as aging. According to this model, the state of youth is akin to a forest of spinning tops standing stable, fast and full of energy. Old age sees them slowing down, growing unsteady, oscillating wildly—ready for a passing breeze to knock swathes of them over.
Entropy does not cause disease, nor is it disease, but it leaves an organism vulnerable. And disease takes hold where the system is weakest. For humans that is the cardiovascular system and those cell populations most prone to cancer.
Having made great strides against communicable disease in the opening decades of the twentieth century, we are now up against the limits set by entropy.
In a sense, we have transcended the fate of other organisms, leaving behind the eternal war among species and microorganisms that operates to kill such large fractions of a population in early life, and—barring accident—we are left to behave more like the objects in the physical world around us, winding down as entropy takes hold, left to fail the way a star might.
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MR. HUDSON’S CHEST is full of crackles. His cough is worse today, his breathing more labored. The pneumonia that first brought him to the hospital has returned. I am unsure what the kindest intervention might now be.
At the start of the twentieth century, the continent of old age was a destination that stood rarely visited and largely unknown. For nearly the entirety of human history, average life expectancy languished around thirty years of age. This grim statistic remained fairly constant throughout recorded history, about as true of the ancient Greeks as it was of the Victorians of the nineteenth century.
In the time that James Hudson has lived, life expectancy in the United Kingdom has nearly doubled. The oldest person who has ever lived was nineteen years older than he is now when she died at the remarkable age of 122 years and 164 days in 1997.
Jeanne Calment, born in the 1870s, lived for her entire life in the French city of Arles and, as a young woman, once met Vincent van Gogh. It is hard to make sense of her longevity. She smoked, ate chocolate, drank port, and according to reports, wasn’t particularly fussed about exercise—hardly the behavior of an individual attempting to stave off the inevitable running down of her physiological processes.
There are but a handful of people alive today who have approached this great age. Fewer than one in a thousand centenarians reaches the age of 110. Could Mr. Hudson pass this extreme frontier? Statistically, the chances appear slim. But we are in terra incognita here, living at a time when we are seeing remarkable feats of survival and longevity occur more and more commonly.
We are increasingly aware that a patient’s chronological age is not the same thing as physiological age and that it’s a mistake to underestimate those who’ve passed their allotted threescore years and ten. After all, John Glenn flew into space aboard the space shuttle Discovery at age 77. Jeanne Calment herself took up fencing for the first time at age 85. And at 102 years of age, Dr. James Hudson described himself in the national census as merely “semiretired.” As his doctor, I have no direct way of knowing how well preserved Mr. Hudson is, only that he is resilient enough to have made it this far.
My patient is arguably less likely to die on this day than he was on any day at Arras, Mons, or Ypres, and only slightly more likely to die today than he was in his first year of life. But Mr. Hudson is an individual—more different from the population upon which that statistic is based than he has been at any time in his life. He has seen unthinkable revolutions in health care, science, and technology. He has seen the seemingly impossible achieved over and over again. And for him, the only constant through all of that time has been the fact of his survival.
Tucked up in bed fighting pneumonia, he is still in many ways the same plucky private from the Western Front—keeping his head down, knowing only that this is war and that all wars are hard.
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“NOBODY,” AS SENATOR AND ASTRONAUT John Glenn once put it, “has yet found a cure for the common birthday.” But for those fortunate enough to live in the developed countries of the world, the continent of old age is, after two million years of human evolution, suddenly open to all. Equipped with only average luck, assisted by the advances that modern living has brought, the vast majority of us will reach it.
We may find difficulty in perceiving old age as a thing of exploration, but that it is—and one in which all of us today can participate. Neither do we regard it in the same way as we do other unexplored destinations: with expectation, hope, and curiosity.
But life is an exploration, and James Hudson is among the greatest explorers of any age, living across three centuries, witness to some of the most significant events of the twentieth century. To him it was all an adventure and one to be enjoyed until the last possible moment.
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ENTROPY, DISEASE, AND THE COMPLEXION of our genes eventually catch up with us all, even those who have walked upon the Moon. On August 25, 2012, Neil Armstrong died in a hospital in the city of Cincinnati, Ohio, having failed to fully recover after cardiac surgery. He was eighty-two. Earlier that month, he had stepped onto a treadmill and walked, while doctors monitored the dance of electricity in his heart through electrocardiogram leads.
They perhaps noticed small upswings and depressions in the waveforms scribbled out before them, symptomatic of constrictions in the arteries supplying the muscle of his heart. They would have gone on to map those tributaries in greater detail, delineating the number and severity of the narrowings, before deciding upon a plan. That plan was for Armstrong to undergo a cardiothoracic operation in an effort to bypass the blockages in his coronary arteries and restore the supply routes to his heart.
Bypass operations were pioneered in the same decade in which Project Apollo reached the Moon. This type of surgery remains among the most invasive that medicine offers—carving into the chest, isolating the heart from its surroundings, and establishing the patient on a heart-lung bypass machine—and it comes with attendant risks. This Armstrong’s surgical team would have labored to explain, weighing the alternatives, making clear what might be won and lost in the endeavor.
Precisely how you stratify risk to a man who commanded the first crew to land on the Moon, or how Armstrong himself perceived it, I do not know. Despite his earlier occupation, Armstrong was no adrenaline junky. Unnecessary risks were, in his opinion, best avoided.
Famously he believed that human spaceflight ought to involve no more risk than making a milk shake. Though back in the summer of 1969, as the lunar module Eagle sank toward the Sea of Tranquility, running low on fuel, its onboard computers having crashed repeatedly, spaceflight still had a long way to go to catch up with the safety record of the milk-shake industry.
The early days of human spaceflight and heart surgery were watched by the world in wide-eyed wonder. The risks involved in these pioneering endeavors were so great as to be impossible to sensibly quantify. Deaths were expected.
Today the risk of catastrophic failure during the launch of a human-rated orbital space vehicle stands at perhaps 2 or 3 percent, almost the same risk as that involved in coronary artery bypass surgery. Despite these risks being significant, both have, to some degree, come to be viewed by the public as being within acceptable limits. They have become almost routine.
The surface of the Moon, like the anatomy of the heart, had been studied for centuries. Both had stood for millennia in full view and yet unexplored. The Moon was reached by an astronaut crew launched across the void, wrapped in a facsimile of Earth’s atmosphere. That same approach—of swaddling physiology in systems of artificial life support—was the key to successful cardiac surgery.
In the few decades that have elapsed since Scott and Amundsen first marched to the South Pole, we have come a long way. Our expectations of the insults we might survive, in the pursuit of geographical conquest as well as on the operating table, have been transformed. Life has never been safer, never longer-lived.
But look closer and the picture gets more complex. Exploration is necessarily a process of trial and error, of taking risks. It appears clear what we have to gain by advancing so boldly as clinicians. But we’re growing more circumspect about physical exploration, particularly that which sees us staring out into space at the final frontier. We’ve begun to wonder if we should continue to boldly go.
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THE AGE OF HUMAN SPACEFLIGHT WAS, without doubt, brought into being by the nuclear arms race of the midtwentieth century. In the 1960s, with the respective nuclear arsenals of the Soviet Union and the United States of America standing ready to bring about their mutually assured destruction, human spaceflight became a surrogate battlefield for a war that couldn’t be fought in any other way.
With the Soviet Union ahead at every point in the space race, there were hard truths for the United States to face. But the reply to Sputnik, Laika, and Gagarin was Armstrong, Aldrin, and Collins. And despite Russia’s earlier preeminence, the lunar landing in July 1969 somehow gave the United States victory in this bizarre struggle.
Project Apollo and its lunar exploration missions were conceived, built, and launched before Kennedy’s famous decade was out. This feat appears to grow more miraculous as the years roll by. The mission-control room that drove those first forays to another world was stocked with slide rules, pocket protectors, and Bakelite telephones with rotating dials. To contemporary eyes, it hardly seems possible that the technology of the time was up to the task of delivering men to the surface of the Moon. In that regard, it is an achievement that stands outside its time, a feat of anachronism.
But perhaps acts of exploration never fully make sense to rational people. They are, after all, about venturing beyond what is known and safe and to be counted on. In this regard, maybe the greatest feats of exploration must always feel anachronistic.
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AFTER HALF A MILLENNIUM, we still remember Ferdinand Magellan and the straits linking the Pacific to the Atlantic to which he gave his name. We might remember, too, the extraordinary voyage that saw his flotilla of ships become the first expedition to circumnavigate the globe. The legacy of discovery is what we celebrate. What we recall less clearly is the expedition’s legacy of loss.
For Magellan, setting sail from the Spanish port of Sanlúcar de Barrameda in 1519 with a fleet of five ships and a crew of 237, the oceans of the world must have seemed as unknown, presenting at least as much threat to life as the ocean of space that lies between Earth and Mars today.
The expedition endured famine, disease, mutiny, and conflict. Magellan himself was slain in the Philippines, in the shallows around Mactan Island, before the circumnavigation was complete. When the expedition finally returned to port in 1522, exactly three years after its departure, only one ship, the Victoria, and 18 of the original crew of 237 remained.
Today history recognizes this as having been an important feat of exploration, a necessary step toward still greater feats of naval discovery. But to Magellan’s crew and the people who lived and worked in the Spanish port into which the Victoria limped at the start of the sixteenth century, it could hardly have seemed so.
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IN RETELLING THE STORY of twentieth-century medicine, we often superimpose a narrative of steady progress, when in truth physicians, surgeons, and scientists did little more than stumble ahead, as all explorers do, solving and creating problems as they went.
Both Charles Bailey and Dwight Harken endured many failures in the early days of closed-heart surgery, resulting in the deaths of a very large percentage of their first cohort of patients. These first efforts at heart surgery were viewed as bizarre and extreme forms of intervention. So too was Archibald McIndoe’s practice of subjecting disfigured airmen to dozens of operations, waltzing squares of flesh across their bodies in the hope of reconstructing something of their faces. Bjørn Ibsen only narrowly convinced his colleagues of the value of artificial ventilation in addressing the devastating effects of poliomyelitis.
Faced either with the scars of the Battle of Britain or the suffocating death of the polio epidemics, both McIndoe and Ibsen could have safely chosen to do nothing. In both cases, the threats addressed by their innovation were rapidly neutralized by other means. Aircraft, even combat aircraft, became immeasurably safer through improved engineering. Polio was addressed effectively with programs of vaccination. Within twenty years of the Copenhagen epidemic that gave rise to the world’s first intensive-care units, the specter of this paralyzing illness had all but disappeared from developed countries, and today polio is very nearly eradicated from the world at large.
But the intensive-care units that Bjørn Ibsen labored to create were soon repurposed to treat all sufferers of critical illness—within three decades, we could artificially support lungs, hearts, kidneys, and even the gut. And intensive care came to underpin the heroic feats of surgery that we have come to expect in the modern age, Dallas Wiens and his transplanted face among them.
Plastic surgery also underwent something of a transformation. The devastation and disfiguration wrought by fires became thankfully rarer over the course of the last hundred years. Its ravages have been replaced by the invasion of cancer. And it is here that the art of plastic surgery, forged in the fire of war, now finds itself most keenly applied. None of these destinations was arrived at through careful planning. But when you strike out into new territory, you rarely know what you’re going to discover.
Together, dozens of discrete events in the history of modern medicine came together to ensure Anna Bågenholm’s survival. From flying ambulances and cardiac-bypass circuits to intensive-care units and reconstructive surgeries, all of it eventually became a continuous chain of survival that took a young doctor from death beneath the ice of a frozen river in Norway to resuscitation and survival in a hospital in Tromsø. Anna’s survival was one of the unintended consequences of the exploration of earlier epochs. In part, that answers the question of why we should explore at all. To be able to explore, we must continue to survive. But the reverse is also true. To survive, we must explore.
We advance in science, medicine, and exploration in fits and starts. There is no real plan—at least not one that anyone has ever stuck to for very long. We happen upon our discoveries largely by accident, making the most of them as and when they arise. We meet disaster in the same way. We explore simply because we must. And that is what makes us human.