Engines of Creation: The Coming Era of Nanotechnology

A DOOR TO THE FUTURE

(Chapter 9)

London, April 1773. To Jacques Dubourg. Your observations on the causes of death, and the experiments which you propose for recalling to life those who appear to be killed by lightning, demonstrate equally your sagacity and your humanity. It appears that the doctrine of life and death in general is yet but little understood... I wish it were possible... to invent a method of embalming drowned persons, in such a manner that they might be recalled to life at any period, however distant; for having a very ardent desire to see and observe the state of America a hundred years hence, I should prefer to an ordinary death, being immersed with a few friends in a cask of Madeira, until that time, then to be recalled to life by the solar warmth of my dear country! But... in all probability, we live in a century too little advanced, and too near the infancy of science, to see such an art brought in our time to its perfection... I am, etc. - B. FRANKLIN.

BENJAMIN FRANKLIN wanted a procedure for stopping and restarting metabolism, but none was then known. Do we live in a century far enough advanced to make biostasis available - to open a future of health to patients who would otherwise lack any choice but dissolution after they have expired?

We can stop metabolism in many ways, but biostasis, to be of use, must be reversible. This leads to a curious situation. Whether we can place patients in biostasis using present techniques depends entirely on whether future techniques will be able to reverse the process. The procedure has two parts, of which we must master only one.

If biostasis can keep a patient unchanged for years, then those future techniques will include sophisticated cell repair systems. We must therefore judge the success of present biostasis procedures in light of the ultimate abilities of future medicine. Before cell repair machines became a clear prospect, those abilities - and thus the requirements for successful biostasis - remained grossly uncertain. Now, the basic requirements seem fairly obvious.

The Requirements for Biostasis

Molecular machines can build cells from scratch, as dividing cells demonstrate. They can also build organs and organ systems from scratch, as developing embryos demonstrate. Physicians will be able to use cell repair technology to direct the growth of new organs from a patient's own cells. This gives modern physicians great leeway in biostasis procedures: even if they were to damage or discard most of a patient s organs, they would still do no irreversible harm. Future colleagues with better tools will be able to repair or replace the organs involved. Most people would be glad to have a new heart, fresh kidneys, or younger skin.

But the brain is another matter. A physician who allows the destruction of a patient's brain allows the destruction of the patient as a person, whatever may happen to the rest of the body. The brain holds the patterns of memory, of personality, of self. Stroke patients lose only parts of their brains, yet suffer harm ranging from partial blindness to paralysis to loss of language, lowered intelligence, altered personality, and worse. The effects depend on the location of the damage. This suggests that total destruction of the brain causes total blindness, paralysis, speechlessness, and mindlessness, whether the body continues to breathe or not.

As Voltaire wrote, "To rise again - to be the same person that you were - you must have your memory perfectly fresh and present; for it is memory that makes your identity. If your memory be lost, how will you be the same man?" Anesthesia interrupts consciousness without disrupting the structure of the brain, and biostasis procedures must do likewise, for a longer time. This raises the question of the nature of the physical structures that underlie memory and personality.

Neurobiology, and informed common sense, agree on the basic nature of memory. As we form memories and develop as individuals, our brains change. These changes affect the brain's function, changing its pattern of activity: When we remember, our brains do something; when we act, think, or feel, our brains do something. Brains work by means of molecular machinery. Lasting changes in brain function involve lasting changes in this molecular machinery - unlike a computer's memory, the brain is not designed to be wiped clean and refilled at a moment's notice. Personality and long-term memory are durable.

Throughout the body, durable changes in function involve durable changes in molecular machinery. When muscles become stronger or swifter, their proteins change in number and distribution. When a liver adapts to cope with alcohol, its protein content also changes. When the immune system learns to recognize a new kind of influenza virus, protein content changes again. Since protein-based machines do the actual work of moving muscles, breaking down toxins, and recognizing viruses, this relationship is to be expected.

In the brain, proteins shape nerve cells, stud their surfaces, link one cell to the next, control the ionic currents of each neural impulse, produce the signal molecules that nerve cells use to communicate across synapses, and much, much more. When printers print words, they put down patterns of ink; when nerve cells change their behavior, they change their patterns of protein. Printing also dents the paper, and nerve cells change more than just their proteins, yet the ink on the paper and the proteins in the brain are enough to make these patterns clear. The changes involved are far from subtle. Researchers report that long-term changes in nerve cell behavior involve "striking morphological changes" in synapses: they change visibly in size and structure.

It seems that long-term memory is not some terribly delicate pattern, ready to evaporate from the brain at any excuse. Memory and personality are instead firmly embodied in the way that brain cells have grown together, in patterns formed through years of experience. Memory and personality are no more material than the characters in a novel; yet like them they are embodied in matter. Memory and personality do not waft away on the last breath as a patient expires. Indeed, many patients have recovered from so-called "clinical death," even without cell repair machines to help. The patterns of mind are destroyed only when and if the attending physicians allow the patient's brain to undergo dissolution. This again allows physicians considerable leeway in biostasis procedures: typically, they need not stop metabolism until after vital functions have ceased.

It seems that preserving the cell structures and protein patterns of the brain will also preserve the structure of the mind and self. Biologists already know how to preserve tissue this well. Resuscitation technology must await cell repair machines, but biostasis technology seems well in hand.

Methods of Biostasis

The idea that we already have biostasis techniques may seem surprising, since powerful new abilities seldom spring up overnight. In fact, the techniques are old - only understanding of their reversibility is new. Biologists developed the two main approaches for other reasons.

For decades, biologists have used electron microscopes to study the structure of cells and tissues. To prepare specimens, they use a chemical process called fixation to hold molecular structures in place. A popular method uses glutaraldehyde molecules, flexible chains of five carbon atoms with a reactive group of hydrogen and oxygen atoms at each end. Biologists fix tissue by pumping a glutaraldehyde solution through blood vessels, which allows glutaraldehyde molecules to diffuse into cells. A molecule tumbles around inside a cell until one end contacts a protein (or other reactive molecule) and bonds to it. The other end then waves free until it, too, contacts something reactive. This commonly shackles a protein molecule to a neighboring molecule.

These cross-links lock molecular structures and machines in place; other chemicals then can be added to do a more thorough or sturdy job. Electron microscopy shows that such fixation procedures preserve cells and the structures within them, including the cells and structures of the brain.

The first step of the hypothetical biostasis procedure that I described in Chapter 7 involved simple molecular devices able to enter cells, block their molecular machinery, and tie structures together with stabilizing cross-links. Glutaraldehyde molecules fit this description quite well. The next step in this procedure involved other molecular devices able to displace water and pack themselves solidly around the molecules of a cell. This also corresponds to a known process.

Chemicals such as propylene glycol, ethylene glycol, and dimethyl sulfoxide can diffuse into cells, replacing much of their water yet doing little harm. They are known as - cryoprotectants," because they can protect cells from damage at low temperatures. If they replace enough of a cell's water, then cooling doesn't cause freezing, it just causes the protectant solution to become more and more viscous, going from a liquid that resembles thin syrup in its consistency to one that resembles hot tar, to one that resembles cold tar, to one as resistant to flow as a glass. In fact, according to the scientific definition of the term, the protectant solution then qualifies as a glass; the process of solidification without freezing is called vitrification. Mouse embryos vitrified and stored in liquid nitrogen have grown into healthy mice.

The vitrification process packs the glassy protectant solidly around the molecules of each cell; vitrification thus fits the description I gave of the second stage of biostasis.

Fixation and vitrification together seem adequate to ensure long-term biostasis. To reverse this form of biostasis, cell repair machines will be programmed to remove the glassy protectant and the glutaraldehyde cross-links and then repair and replace molecules, thus restoring cells, tissues, and organs to working order.

Fixation with vitrification is not the first procedure proposed for biostasis. In 1962 Robert Ettinger, a professor of physics at Highland Park College in Michigan, published a book suggesting that future advances in cryobiology might lead to techniques for the easily reversible freezing of human patients. He further suggested that physicians using future technology might be able to repair and revive patients frozen with present techniques shortly after cessation of vital signs. He pointed out that liquid nitrogen temperatures will preserve patients for centuries, if need be, with little change. Perhaps, he suggested, medical science will one day have fabulous machines able to restore frozen tissue a molecule at a time. His book gave rise to the cryonics movement.

Cryonicists have focused on freezing because many human cells revive spontaneously after careful freezing and thawing. It is a common myth that freezing bursts cells; in fact, freezing damage is more subtle than this - so subtle that it often does no lasting harm. Frozen sperm regularly produces healthy babies. Some human beings now alive have survived being frozen solid at liquid nitrogen temperatures - when they were early embryos. Cryobiologists are actively researching ways to freeze and thaw viable organs to allow surgeons to store them for later implantation.

The prospect of future cell repair technologies has been a consistent theme among cryonicists. Still, they have tended to focus on procedures that preserve cell function, for natural reasons. Cryobiologists have kept viable human cells frozen for years. Researchers have improved their results by experimenting with mixes of cryoprotective chemicals and carefully controlled cooling and warming rates. The complexities of cryobiology offer rich possibilities for further experimentation. This combination of tangible, tantalizing success and promising targets for further research has made the quest for an easily reversible freezing process a vivid and attractive goal for cryonicists. A success at freezing and reviving an adult mammal would be immediately visible and persuasive.

What is more, even partial preservation of tissue function suggests excellent preservation of tissue structure. Cells that can revive (or almost revive) even without special help will need little repair.

The cryonics community's cautious, conservative emphasis on preserving tissue function has invited public confusion, though. Experimenters have frozen whole adult mammals and thawed them without waiting for the aid of cell repair machines. The results have been superficially discouraging: the animals fail to revive. To a public and a medical community that has known nothing about the prospects for cell repair, this has made frozen biostasis seem pointless.

And, after Ettinger's proposal, a few cryobiologists chose to make unsupported pronouncements about the future of medical technology. As Robert Prehoda stated in a 1967 book: "Almost all reduced-metabolism experts . . . believe that cellular damage caused by current freezing techniques could never be corrected." Of course, these were the wrong experts to ask. The question called for experts on molecular technology and cell repair machines. These cryobiologists should have said only that correcting freezing damage would apparently require molecular-level repairs, and that they, personally, had not studied the matter. Instead, they casually misled the public on a matter of vital medical importance. Their statements discouraged the use of a workable biostasis technique.

Cells are mostly water. At low enough temperatures, water molecules join to form a weak but solid framework of cross-links. Since this preserves neural structures and thus the patterns of mind and memory, Robert Ettinger has apparently identified a workable approach to biostasis. As molecular technology advances and people grow familiar with its consequences, the reversibility of biostasis (whether based on freezing, fixation and vitrification, or other methods) will grow ever more obvious to ever more people.

Reversing Biostasis

Imagine that a patient has expired because of a heart attack. Physicians attempt resuscitation but fail, and give up on restoring vital functions. At this point, though, the patient's body and brain are just barely nonfunctional - most cells and tissues, in fact, are still alive and metabolizing. Having made arrangements beforehand, the patient is soon placed in biostasis to prevent irreversible dissolution and await a better day.

Years pass. The patient changes little, but technology advances greatly. Biochemists learn to design proteins. Engineers use protein machines to build assemblers, then use assemblers to build a broad-based nanotechnology. With new instruments, biological knowledge explodes. Biomedical engineers use new knowledge, automated engineering, and assemblers to develop cell repair machines of growing sophistication. They learn to stop and reverse aging. Physicians use cell repair technology to resuscitate patients in biostasis - first those placed in biostasis by the most advanced techniques, then those placed in biostasis using earlier and cruder techniques. Finally, after the successful resuscitation of animals placed in biostasis using the old techniques of the 1980s, physicians turn to our heart-attack patient.

In the first stage of preparation, the patient lies in a tank of liquid nitrogen surrounded by equipment. Glassy protectant still locks each cell's molecular machinery in a firm embrace. This protectant must be removed, but simple warming might allow some cell structures to move about prematurely.

Surgical devices designed for use at low temperatures reach through the liquid nitrogen to the patient's chest. There they remove solid plugs of tissue to open access to major arteries and veins. An army of nanomachines equipped for removing protectant moves through these openings, clearing first the major blood vessels and then the capillaries. This opens paths throughout the normally active tissues of the patient's body. The larger surgical machines then attach tubes to the chest and pump fluid through the circulatory system. The fluid washes out the initial protectant-removal machines (later, it supplies materials to repair machines and carries away waste heat).

Now the machines pump in a milky fluid containing trillions of devices that enter cells and remove the glassy protectant, molecule by molecule. They replace it with a temporary molecular scaffolding that leaves ample room for repair machines to work. As these protectant-removal machines uncover biomolecules, including the structural and mechanical components of the cells, they bind them to the scaffolding with temporary cross-links. (If the patient had also been treated with a cross-linking fixative, these cross-links would now be removed and replaced with the temporary links.) When molecules must be moved aside, the machines label them for proper replacement. Like other advanced cell repair machines, these devices work under the direction of on-site nanocomputers.

When they finish, the low-temperature machines withdraw. Through a series of gradual changes in composition and temperature, a water-based solution replaces the earlier cryogenic fluid and the patient warms to above the freezing point. Cell repair machines are pumped through the blood vessels and enter the cells. Repairs commence.

Small devices examine molecules and report their structures and positions to a larger computer within the cell. The computer identifies the molecules, directs any needed molecular repairs, and identifies cell structures from molecular patterns. Where damage has displaced structures in a cell, the computer directs the repair devices to restore the molecules to their proper arrangement, using temporary cross-links as needed. Meanwhile, the patient's arteries are cleared and the heart muscle, damaged years earlier, is repaired.

Finally, the molecular machinery of the cells has been restored to working order, and coarser repairs have corrected damaged patterns of cells to restore tissues and organs to a healthy condition. The scaffolding is then removed from the cells, together with most of the temporary cross-links and much of the repair machinery. Most of each cell's active molecules remain blocked, though, to prevent premature, unbalanced activity.

Outside the body, the repair system has grown fresh blood from the patient's own cells. It now transfuses this blood to refill the circulatory system, and acts as a temporary artificial heart. The remaining devices in each cell now adjust the concentration of salts, sugars, ATP, and other small molecules, largely by selectively unblocking each cell's own nanomachinery. With further unblocking, metabolism resumes step by step; the heart muscle is finally unblocked on the verge of contraction. Heartbeat resumes, and the patient emerges into a state of anesthesia. While the attending physicians check that all is going well, the repair system closes the opening in the chest, joining tissue to tissue without a stitch or a scar. The remaining devices in the cells disassemble one another into harmless waste or nutrient molecules. As the patient moves into ordinary sleep, certain visitors enter the room, as long planned.

At last, the sleeper wakes refreshed to the light of a new day - and to the sight of old friends.

Mind, Body, & Soul

Before considering resuscitation, however, some may ask what becomes of the soul of a person in biostasis. Some people would answer that the soul and the mind are aspects of the same thing, of a pattern embodied in the substance of the brain, active during active life and quiescent in biostasis. Assume, though, that the pattern of mind, memory, and personality leaves the body at death, carried by some subtle substance. The possibilities then seem fairly clear. Death in this case has a meaning other than irreversible damage to the brain, being defined instead by the irreversible departure of the soul. This would make biostasis a pointless but harmless gesture - after all, religious leaders have expressed no concern that mere preservation of the body can somehow imprison a soul. Resuscitation would, in this view, presumably require the cooperation of the soul to succeed. The act of placing patients in biostasis has in fact been accompanied by both Catholic and Jewish ceremonies.

With or without biostasis, cell repair cannot bring immortality. Physical death, however greatly postponed, will remain inevitable for reasons rooted in the nature of the universe. Biostasis followed by cell repair thus seems to raise no fundamental theology. It resembles deep anesthesia followed by life-saving surgery: both procedures interrupt consciousness to prolong life. To speak of "immortality" when the prospect is only long life would be to ignore the facts or to misuse words.

Reactions & Arguments

The prospect of biostasis seems tailor-made to cause future shock. Most people find today's accelerating change shocking enough when it arrives a bit at a time. But the biostasis option is a present-day consequence of a whole series of future breakthroughs. This prospect naturally upsets the difficult psychological adjustments that people make in dealing with physical decline.

Thus far, I have built the case for cell repair and biostasis on a discussion of the commonplace facts of biology and chemistry. But what do professional biologists think about the basic issues? In particular, do they believe (1) that repair machines will be able to correct the kind of cross-linking damage produced by fixation, and (2) that memory is indeed embodied in a preservable form?

After a discussion of molecular machines and their capabilities - a discussion not touching on medical implications - Dr. Gene Brown, professor of biochemistry and chairman of the department of biology at MIT, gave permission to be quoted as stating that: "Given sufficient time and effort to develop artificial molecular machines and to conduct detailed studies of the molecular biology of the cell, very broad abilities should emerge. Among these could be the ability to separate the proteins (or other biomolecules) in cross-linked structures, and to identify, repair, and replace them." This statement addresses a significant part of the cell repair problem. It was consistently endorsed by a sample of biochemists and molecular biologists at MIT and Harvard after similar discussions.

After a discussion of the brain and the physical nature of memory and personality - again, a discussion not touching on medical implications - Dr. Walle Nauta (Institute Professor of Neuroanatomy at MIT) gave permission to be quoted as stating that: "Based on our present knowledge of the molecular biology of neurons, I think most would agree that the changes produced during the consolidation of long-term memory are reflected in corresponding changes in the number and distribution of different protein molecules in the neurons of the brain." Like Dr. Brown's statement, this addresses a key point regarding the workability of biostasis. It, too, was consistently endorsed by other experts when discussed in a context that insulated the experts from any emotional bias that might result from the medical implications of the statement. Further, since these points relate directly to their specialties, Dr. Brown and Dr. Nauta were appropriate experts to ask.

It seems that the human urge to live will incline many millions of people toward using biostasis (as a last resort) tf they consider it workable. As molecular technology advances, understanding of cell repair will spread through the popular culture. Expert opinion will increasingly support the idea. Biostasis will grow more common, and its costs will fall. It seems likely that many people will eventually consider biostasis to be the norm, to be a standard lifesaving treatment for patients who have expired.

But until cell repair machines are demonstrated, the all too human tendency to ignore what we haven't seen will slow the acceptance of biostasis. Millions will no doubt pass from expiration to irreversible dissolution because of habit and tradition, supported by weak arguments. The importance of clear foresight in this matter makes it important to consider possible arguments before leaving the topic of life extension and moving on to other matters. Why, then, might biostasis not seem a natural, obvious idea?

Because cell repair machines aren't here yet.

It may seem strange to save a person from dissolution in the expectation of restoring health, since the repair technology doesn't exist yet. But is this so much stranger than saving money to put a child through college? After all, the college student doesn't exist yet, either. Saving money makes sense because the child will mature; saving a person makes sense because molecular technology will mature.

We expect a child to mature because we have seen many children mature; we can expect this technology to mature because we have seen many technologies mature. True, some children suffer from congenital shortcomings, as do some technologies, but experts often can estimate the potential of children or technologies while they remain young.

Microelectronic technology started with a few spots and wires on a chip of silicon, but grew into computers on chips. Physicists such as Richard Feynman saw, in part, how far it would lead.

Nuclear technology started with a few atoms splitting in the laboratory under neutron bombardment, but grew into billion-watt reactors and nuclear bombs. Leo Szilard saw, in part, how far it would lead.

Liquid rocket technology started with crude rockets launched from a Massachusetts field, but grew into Moonships and space shuttles. Robert Goddard saw, in part, how far it would lead.

Molecular engineering has started with ordinary chemistry and molecular machines borrowed from cells, but it, too, will grow mighty. It, too, has discernible consequences.

Because tiny machines lack drama.

We tend to expect dramatic results only from dramatic causes, but the world often fails to cooperate. Nature delivers both triumph and disaster in brown paper wrappers.

DULL FACT: Certain electric switches can turn one another on and off. These switches can be made very small, and frugal of electricity.
THE DRAMATIC CONSEQUENCE: When properly connected, these switches form computers, the engines of the information revolution.

DULL FACT: Ether is not too poisonous, yet temporarily interferes with the activity of the brain.
THE DRAMATIC CONSEQUENCE: An end to the agony of surgery on conscious patients, opening a new era in medicine.

DULL FACT: Molds and bacteria compete for food, so some molds have evolved to secrete poisons that kill bacteria.
THE DRAMATIC CONSEQUENCE: Penicillin, the conquest of many bacterial diseases, and the saving of millions of lives.

DULL FACT: Molecular machines can be used to handle molecules and build mechanical switches of molecular size.
THE DRAMATIC CONSEQUENCE: Computer-directed cell repair machines, bringing cures for virtually all diseases.

DULL FACT: Memory and personality are embodied in preservable brain structures.
THE DRAMATIC CONSEQUENCE: Present techniques can prevent dissolution, letting the present generation take advantage of tomorrow's cell repair machines.

In fact, molecular machines aren't even so dull. Since tissues are made of atoms, one should expect a technology able to handle and rearrange atoms to have dramatic medical consequences.

Because this seems too incredible.

We live in a century of the incredible.

In an article entitled "The Idea of Progress" in Astronautics and Aeronautics, aerospace engineer Robert T. Jones wrote: "In 1910, the year I was born, my father was a prosecuting attorney. He traveled all the dirt roads in Macon County in a buggy behind a single horse. Last year I flew nonstop from London to San Francisco over the polar regions, pulled through the air by engines of 50,000 horsepower." In his father's day, such aircraft lay at the fringe of science fiction, too incredible to consider.

In an article entitled "Basic Medical Research: A Long-Term Investment" in MIT's Technology Review, Dr. Lewis Thomas wrote: "Forty years ago, just before the profession underwent transformation from an art to science and technology, it was taken for granted that the medicine we were being taught was precisely the medicine that would be with us for most of our lives. If anyone had tried to tell us that the power to control bacterial infections was just around the corner, that open-heart surgery or kidney transplants would be possible within a couple of decades, that some kinds of cancer could be cured by chemotherapy, and that we would soon be within reach of a comprehensive, biochemical explanation for genetics and genetically determined diseases, we would have reacted in blank disbelief. We had no reason to believe that medicine would ever change.... What this recollection suggests is that we should keep our minds wide open in the future."

Because this sounds too good to be true.

News of a way to avoid the fatality of most fatal diseases may indeed sound too good to be true - as it should, since it is but a small part of a more balanced story. In fact, the dangers of molecular technology roughly balance its promise. In Part Three I will outline reasons for considering nanotechnology more dangerous than nuclear weapons.

Fundamentally, though, nature cares nothing for our sense of good and bad and nothing for our sense of balance. In particular, nature does not hate human beings enough to stack the deck against us. Ancient horrors have vanished before.

Years ago, surgeons strove to amputate legs fast. Robert Liston of Edinburgh, Scotland, once sawed through a patient's thigh in a record thirty-three seconds, removing three of his assistant's fingers in the process. Surgeons worked fast to shorten their patients' agony, because their patients remained conscious.

If terminal illness without biostasis is a nightmare today, consider surgery without anesthesia in the days of our ancestors: the knife slicing through flesh, the blood flowing, the saw grating on the bone of a conscious patient. . . . Yet in October of 1846, W. T. G. Morton and J. C. Warren removed a tumor from a patient under ether anesthesia; Arthur Slater states that their success "was rightly hailed as the great discovery of the age." With simple techniques based on a known chemical, the waking nightmare of knife and saw at long last was ended.

With agony ended, surgery increased, and with it surgical infection and the horror of routine death from flesh rotting in the body. Yet in 1867 Joseph Lister published the results of his experiments with phenol, establishing the principles of antiseptic surgery. With simple techniques based on a known chemical, the nightmare of rotting alive shrank dramatically.

Then came sulfa drugs and penicillin, which ended many deadly diseases in a single blow... the list goes on.

Dramatic medical breakthroughs have come before, sometimes from new uses of known chemicals, as in anesthesia and antiseptic surgery. Though these advances may have seemed too good to be true, they were true nonetheless. Saving lives by using known chemicals and procedures to produce biostasis can likewise be true. Because doctors don't use biostasis today.

Robert Ettinger proposed a biostasis technique in 1962. He states that Professor Jean Rostand had proposed the same approach years earlier, and had predicted its eventual use in medicine. Why did biostasis by freezing fail to become popular? In part because of its initial expense, in part because of human inertia, and in part because means for repairing cells remained obscure. Yet the ingrained conservatism of the medical profession has also played a role. Consider again the history of anesthesia.

In 1846, Morton and Warren amazed the world with the "discovery of the age", ether anesthesia. Yet two years earlier, Horace Wells had used nitrous oxide anesthesia, and two years before that, Crawford W. Long had performed an operation using ether. In 1824, Henry Hickman had successfully anesthetized animals using ordinary carbon dioxide; he later spent years urging surgeons in England and France to test nitrous oxide as an anesthetic. In 1799, a full forty-seven years before the great "discovery", and years before Liston's assistant lost his fingers, Sir Humphry Davy wrote: "As nitrous oxide in its extensive operation appears capable of destroying physical pain, it may possibly be used during surgical operations."

Yet as late as 1839 the conquest of pain still seemed an impossible dream to many physicians. Dr. Alfred Velpeau stated: "The abolishment of pain in surgery is a chimera. It is absurd to go on seeking it today. 'Knife' and 'pain' are two words in surgery that must forever be associated in the consciousness of the patient. To this compulsory combination we shall have to adjust ourselves."

Many feared the pain of surgery more than death itself. Perhaps the time has come to awaken from the final medical nightmare.

Because it hasn't been proved to work.

It is true that no experiment can now demonstrate the resuscitation of a patient in biostasis. But a demand for such a demonstration would carry the hidden assumption that modern medicine has neared the final limits of the possible, that it will never be humbled by the achievements of the future. Such a demand might sound cautious and reasonable, but in fact it would smack of overwhelming arrogance.

Unfortunately, a demonstration is exactly what physicians have been trained to request, and for good reason: they wish to avoid useless procedures that may do harm. Perhaps it will suffice that neglect of biostasis leads to obvious and irreversible harm.

Time, Cost, & Human Action

Whether people choose to use biostasis will depend on whether they see it as worth the gamble. This gamble involves the value of life (which is a personal matter), the cost of biostasis (which seems reasonable by the standards of modern medicine), the odds that the technology will work (which seem excellent), and the odds that humanity will survive, develop the technology, and revive people. This final point accounts for most of the overall uncertainty.

Assume that human beings and free societies will indeed survive. (No one can calculate the odds of this, but to assume failure would discourage the very efforts that will promote success.) If so, then technology will continue to advance. Developing assemblers will take years. Studying cells and learning to repair the tissues of patients in biostasis will take still longer. At a guess, developing repair systems and adapting them to resuscitation will take three to ten decades, though advances in automated engineering may speed the process.

The time required seems unimportant, however. Most resuscitated patients will care more about the conditions of life - including the presence of their friends and family - than they will care about the date on the calendar. With abundant resources, the physical conditions of life could be very good indeed. The presence of companions is another matter.

In a recently published survey, over half of those responding said that they would like to live for at least five hundred years, if given a free choice. Informal surveys show that most people would prefer biostasis to dissolution, if they could regain good health and explore a new future with old companions. A few people say that they "want to go when their time comes," but they generally agree that, so long as they can choose further life, their time has not yet come. It seems that many people today share Benjamin Franklin's desire, but in a century able to satisfy it. If biostasis catches on fast enough (or if other life-extension technologies advance fast enough), then a resuscitated patient will awake not to a world of strangers, but to the smiles of familiar faces.

But will people in biostasis be resuscitated? Techniques for placing patients in biostasis are already known, and the costs could become low, at least compared to the costs of major surgery or prolonged hospital care. Resuscitation technology, though, will be complex and expensive to develop. Will people in the future bother?

It seems likely that they will. They may not develop nanotechnology with medicine in mind - but if not, then they will surely develop it to build better computers. They may not develop cell repair machines with resuscitation in mind, but they will surely do so to heal themselves. They may not program repair machines for resuscitation as an act of impersonal charity, but they will have time, wealth, and automated engineering systems, and some of them will have loved ones waiting in biostasis. Resuscitation techniques seem sure to be developed.

With replicators and space resources, a time will come when people have wealth and living space over a thousandfold greater than we have today. Resuscitation itself will require little energy and material even by today's standards. Thus, people contemplating resuscitation will find little conflict between their self-interest and their humanitarian concerns. Common human motives seem enough to ensure that the active population of the future will awaken those in biostasis.

The first generation that will regain youth without being forced to resort to biostasis may well be with us today. The prospect of biostasis simply gives more people more reason to expect long life - it offers an opportunity for the old and a form of insurance for the young. As advances in biotechnology lead toward protein design, assemblers, and cell repair, and as the implications sink in, the expectation of long life will spread. By broadening the path to long life, the biostasis option will encourage a more lively interest in the future. And this will spur efforts to prepare for the dangers ahead.