A Question of Immortality


William Sims Bainbridge, Ph.D.

Analog magazine, May 2002, Vol. CXXII No. 5, pp. 40-49.

Arthur C. Clarke's 1953 novel, The City and the Stars, concerns an eternal city inhabited by eternal people. In a thousand-year lifetime, they play adventure games in computer-generated virtual reality, create works of art, and enjoy social activities. Then they enter the Hall of Creation to be archived inside the Central Computer. After a few thousand years, they will be reconstituted again, to experience another life before once again entering the archive.

What science fiction imagines, science can realize. Just as Clarke's prophecy of the communications satellite was brought to reality in the 1960s, his idea of cybernetic immortality is nearly within our capability today. Before making the case for it, I will briefly survey the status of more biological approaches: cryonics (freezing), DNA preservation, and brain scanning. These methods have promise, but each may have inescapable limitations.

A fundamental question in talking about immortality is what you actually consider your own personal identity to be. Are you your body? Or are you your unique attitudes, opinions and beliefs? Your memories? Your deeds, reputation, and legal status as a citizen, or the social roles you play? Are you a unique locus of transcendental consciousness, or an already immortal soul? Technological preservation can be more successful with some of these than with others, and you will have to decide which are most important to you personally.

Biological Approaches

The idea that freezing could protect humans against death has been used many times in science fiction. The 1931 story, "The Jameson Satellite," by Neil R. Jones, concerns a scientist who has himself preserved in the cold of outer space for forty million years. The 1938 movie serial, Buck Rogers, begins as the hero's dirigible crashes in snow-covered Alaskan mountains. Buck floods the cabin with experimental "novano gas" which places him and his teenage side-kick into "suspended animation" until they are revived five hundred years later.

The April 2000 issue of Analog contained a nice article by Dr. H. G. Stratmann about the problems of cryonics. Freezing a human body would destroy delicate tissues as the ice crystals expanded like tiny daggers, and low temperature generates chemical toxins. In his 1956 novel, The Door into Summer, Robert Heinlein argued that a living body could be preserved indefinitely by cooling it to four degrees Celsius, near but not quite to the freezing point. Unfortunately, Dr. Stratmann's article points out that cooled even just to 12 degrees Celsius, the hemoglobin in human blood stops delivering oxygen to the cells.

Inspired by stories like "The Jameson Satellite," more than thirty years ago Robert C. W. Ettinger launched the cryonics movement to freeze actual human beings. Perhaps cryonics will eventually develop the equivalent of novano gas, but while we are waiting for that miracle, we had better explore other options.

A partial answer may be found in the preservation of small samples of DNA. The Center for Reproduction of Endangered Species at the San Diego Zoo has established a collection of cryopreserved animal cells, better known as the Frozen Zoo, "to preserve the legacy of life on Earth for future generations." The Coriell Institute for Medical Research has established a repository of cells from human beings with inherited diseases, and a sufficient sample is four teaspoons of blood.

Frozen DNA samples can be stored indefinitely without deterioration. Under favorable conditions, DNA inside bones can be preserved for very long periods without freezing. Indeed, analysis of ancient DNA has become a prime research technique in physical anthropology, and credible studies have reported success in analyzing DNA fragments from Neanderthal specimens tens of thousands of years old.

However, a clone made from your DNA would not be "you" any more than your identical twin would be if you had one, because it would lack your unique memories. A sample of your DNA could be only part of the preservation process, and there would have to be some way of recording the contents of your brain.

Computer entrepreneur Ray Kurzweil has publicized the idea that magnetic resonance imaging (MRI) could be used to read out the neural structure of a person's brain, which then could be simulated inside a computer. Unfortunately, the spatial resolution of MRI is currently far too poor to reveal how individual neurons connect to each other. A voxel (volume pixel) of one cubic millimeter is considered high resolution today, but it can contain as many as 100,000 neurons.

The resolution of MRI improves by increasing the magnetic field strength, which is typically 1 to 3 tesla. A tesla is 20,000 times the Earth's magnetic field. The US Food and Drug Administration currently requires special permission for field strengths above 4 tesla. MRI equipment also employs radio waves. Fluctuating magnetic fields and radio waves can cause peripheral nerve stimulation, in which the person's muscles start twitching and he or she experiences disturbing sensations. At very high strength, they would cook your brain like a microwave oven.

Laboratory methods are being developed to trace the actual connections among neurons, but this is not a simple business. The rootlike structures called dendrites that connect synapses to the neuron cell body can be extremely difficult to disentangle in slices of brain tissue, let alone in the living brain. Human neurons are not hard-wired, and it is quite uncertain how much one would need to know about the fine structure of synapses, glial cells, and neurotransmitter receptors to understand how any group of neurons really interact.

A better course may be to observe how electrical potentials or local metabolisms vary dynamically as a person thinks, perceives, and acts. Some experimenters are working with voltage-sensitive fluorescent dyes, and others are using diluted solutions of calcium indicators. These methods work only on relatively small exposed surfaces of the brain.

Thus, purely biological approaches to immortality may not be the whole answer. Barring the invention of Buck Rogers' novano gas, freezing is a dubious choice. DMA preservation and brain scanning are not ready to provide immortality, but both can make useful contributions to a multidimensional attack on the problem, especially in combination with psychological and behavioral measures.

Social-Psychological Approaches

Over the past century, psychologists and sociologists have created a bewildering array of questionnaire items to measure aspects of a person. The American Psychological Association has recently published a seven-volume series of books describing a vast number of such tests. Anybody can visit the website of the Inter-university Consortium for Political and Social Research and scan through the codebooks of hundreds of questionnaires, gathering useful items by the bushel.

However, many tests are "protected" by copyright, and publishers defend their sources of income. Psychologists try to keep the public from obtaining copies of certain tests because widespread familiarity with them might invalidate their use as diagnostic tools. Unfortunately, most tests have been created for a purpose almost opposite to the one we are interested in here.

To explain, I will use a classic example: the work of Richard Christie in creating the "Mach Scale." Christie belonged to a major tradition in social psychology that sought to discover distinct types of human personality. He noted that the sixteenth-century Italian political theorist, Niccolo Machiavelli, had come to represent guile and deceit in interpersonal relations, so he decided to cull Machiavelli's writings for potential questionnaire items that might reveal people who had a similar perspective.

Christie developed 71 candidate statements, then put them in a questionnaire filled out by 1,196 college students, asking how much they agreed or disagreed with each. The students' responses were scored, and they were divided into those scoring high on Machiavellianism, and those scoring low. Then Christie went through the 71 items to see which discriminated between high and low scorers. This reduced the list to 20 statements that all seemed to be tapping the same personality characteristic, the famous Machiavellianism or "Mach" scale. Half the items were written so that a Machiavellian would tend to agree with them, and the other half so that a Machiavellian would disagree.

One of my students, Lyn Jacobson Hoefer, created what is called a short form of the Mach Scale, reducing the number of items still further. She included the 20-item scale in a questionnaire she administered to 810 college students, and analyzed the results using a statistical technique called factor analysis. Her aim was to find the subset of items that correlated most strongly with each other, while being alert to the possibility that subgroups of items might measure slightly different aspects of Machiavellianism. The 10 items of her short-form Mach Scale are given here in Table 1.

Table 1: A Short Form Machiavellianism Scale

High Mach Tactics:
    1. Never tell anyone the real reason you did something unless it is useful to do so.
    2. It is safest to assume that all people have a vicious streak and it will come out when they are given a chance.
    3. It is wise to flatter important people.
Low Mach Tactics:
    4. Honesty is the best policy in all cases.
    5. There is no excuse for lying to someone else.
    6. One should take action only when sure it is morally right
High Mach Perspective:
    7. Generally speaking, people won't work hard unless they're forced to do so.
    8. The biggest difference between most criminals and other people is that criminals are stupid enough to get caught.
Low Mach Perspective:
    9. Most people are basically good and kind.
    10. Most people who get ahead in the world lead clean, moral lives

Six items concern tactics, providing advice on how you should behave. The other four express perspectives about people and the world. The ten items can also be divided into two groups of five, one set that Machiavellians would tend to agree with (High Mach), and the other that they would disagree with (Low Mach). For many research purposes, one would combine responses to the ten items to get a single number, for example, counting how many of the High Mach items a person agreed with, plus the Low Mach items he or she disagreed with.

Notice that this process began with 71 candidate Machiavellian statements, and used statistical processes of elimination to arrive at just 10 items, and then combined responses to get a single mathematical score. The aim of much quantitative personality research is to discover a few very general dimensions of human variation at a very abstract level. That is the opposite of what you would want if you were trying to discover the multitude of characteristics that made a particular individual unique.

The Question Factory

Based on a decade of work on computerized survey research methodologies, in May 1997, I launched a website called The Question Factory. The aim was to enlist the help of thousands of people to mass produce new questionnaire items covering many of the major spheres of human thought and activity. People were invited to respond to online questionnaires asking them to express themselves by writing anything from a phrase to a paragraph on various topics.

Their responses were then collated, combined, and edited to create new fixed-choice questionnaire items, and I then wrote eight new software modules to administer, archive, and analyze an individual's reactions to these new items.

Late in 1998,1 helped develop a complex web-based questionnaire called Survey2000, on a team led by sociologist James Witte and sponsored by the National Geographic Society (see my article in the July/August 2000 issue of Analog). Survey2000 included an item developed on The Question Factory about the future, and approximately 20,000 adults wrote ideas about how the world might be a century from now. This vast sea of verbiage was distilled down to 2,000 statements, 100 in each of 20 topic categories, and incorporated in a software database called "The Year 2100." Ten of these items from five categories are listed in Table 2.

Table 2: Sample Items in the "Year 2100" Module

    A9. A few giant corporations will have control over all fields of entertainment.
    A67. Classical art will make a comeback, to replace the tawdry, cheap, sensationalism of popular music and movies.
    G27. Governments will lose both revenue and power, because it will be difficult to track, value, and tax the many private currencies that will exist in the digital economy.
    G78. Democracy will be threatened by under-educated, chronically lazy citizens who demand benefits from their government but do not feel responsibility to defend it.
    I9. China will dictate policies to the rest of the worid, feeling its huge population gives it the right to do so.
    I63. The European union will have reclaimed for Europe its former intellectual, financial, and political dominance in world affairs.
    R12. A new major religion will rise to prominence, fed by the masses looking for something to combat the modern world.
    R64. There will be a resurgence of the old Earth-based religions that worship a female deity.
    T33. Environmental protection agencies will mandate more and more expensive fixes for pollution, until the average citizen is unable to afford personal transportation.
    T75. People will have communications devices implanted for a technological form of telepathy or ESP.

"The Year 2100" is a time machine for the imagination that helps you develop your own personal picture of how the world might be a century from now. Like the other modules in the series, it consists of two main parts:

DATA INPUT: In a series of sessions at the computer, you evaluate the 2,000 ideas about what the future will hold for humanity. You judge how good each idea is, on a scale from 1 (bad) to 8 (good), and how likely it is to come true, from 1 (unlikely) to 8 (likely).

DATA ANALYSIS: Several options help you understand yourself better and compile your alternative views of the future. For one example, a statistical analysis measures your optimism or pessimism in 20 areas of life. For another example, your Utopia is a word processing file of the ideas you rated very good but very unlikely.

"Self-Esteem" is the second software module derived from The Question Factory. It is a tool for exploring the image you have of yourself. It provides a record of your values, habits, interactive style, and personality. You evaluate 1,600 personal qualities in terms of how good each quality is and how much you possess it.

The statistical data analysis measures your self-esteem in 20 areas of life. There is also qualitative output. For example, your Ideal is the qualities you rate very good but feel you lack. The Biography function creates a word processing file of your prime qualities, where you may prepare material for your autobiography by describing episodes in your life when you exhibited each of them.

"Experience" is a software tool for exploring the actions and events that make up your life, providing a record of the things you do, the things that happen to you, and the experiences you fear or desire. You judge how good each of 2,000 personal experiences is, and how recently you have had it.

"Beliefs" is a software system for exploring your fundamental assumptions (what you consider true) and your ultimate values (what you consider important). The 2,000 items were collected from a large number of questionnaire respondents in surveys sponsored by The Question Factory. Ten sample items are listed in Table 3.

Table 3: Sample Items in the "Beliefs" Modul

    C8. Humans were meant to reproduce sexually, so cloning is obscene.
    C38. When a beloved child has a terminal disease, cloning can give the child's parents a second opportunity to raise him or her.
    D19. At death we will meet our maker, review our lives, and ask forgiveness for our wrongdoings.
    D72. The traditional view of Heaven - where one is forced to worship an arrogant and self-centered god - is really Hell.
    F14. People who experiment with new forms of life, such as group marriages, should be admired for their courage.
    F39. The traditional family is being destroyed by increased female employment, higher divorce, spreading non-marital fertility, and liberalized sexual codes.
    M38. When humans begin to live on the planet Mars, they should experiment with alternative social systems, creating a meta-utopia composed of varied societies.
    M83. Martian culture should place a premium on personal accountability, responsibility, strong work ethic, and individual skills.
Outer Space:
    O25. The Moon or the Sun could be used for safe disposal of toxic materials and nuclear waste.
    O86. The space program provides a goal and a feeling of long-term purpose for humanity.

"Wisdom" derived its 2,000 items from the Babylon 5 science fiction universe, all 120 hours of SF television plus about 30 books. In Babylon 5 there are many examples of the idea that the human personality could be preserved. In the episode titled "The Deconstruction of Falling Stars," four characters are revived after five hundred years in the form of holograms, but with such complete memories and thought patterns that their ghosts are able to defeat the evil people who restored them to existence. Table 4 lists ten items.

Table 4: Sample Items in the "Wisdom Module" from Babylon 5

    A25. You should be both terrified and reassured to know that there are still wonders in the universe.
    A47. You should explore the past to create a better future.
    E25. The avalanche has already started; it is too late for the pebbles to vote.
     E35. There is a hole in your mind.
    G62. It is an honor to aid any true seekers in their quests.
     G83. All of this will be for nothing, unless we go to the stars.
Order versus Chaos:
    O33. Strength comes through order and discipline.
     O41. One should become an instrument of chaos.
    S51. If you do the right thing for the wrong reasons, the work becomes corrupted.
    S77. If you're falling off a cliff, you might as well try to fly.

"Taste" asks you to evaluate 2,000 foods in terms of how much you like each and believe that each is healthy. The output incidentally encourages you to try new foods and to improve your nutrition.

"Emotions" was created through surveys on The Question Factory asking people to write in what stimuli might cause them to have each of twenty emotions: love, fear, joy, sadness, gratitude, anger, pleasure, pain, pride, shame, desire, hate, satisfaction, frustration, surprise, boredom, lust, disgust, excitement, and indifference. You judge how good 2,000 stimuli are, and how much each would give you one of the 20 particular feelings.

"Association" traces some of the pathways in your neural network by presenting you with 2,000 pairs of words, asking how strongly you associate the words with each other and how important the concepts they describe are to you personally.

These eight modules offer fully 15,600 stimuli, with two responses for each; a total of 31,200 measurements. A person may repeat the modules annually, building up a dynamic record of personality changes and variability over time. Also in the testing phase are two different methods for archiving aspects of your mind. One measures parameters of your short-term memory (or "working memory") by asking you to briefly memorize 5,760 sequences of digits and letters of the alphabet. The other is an extension of the Association software word-association test. A person responds to each of 4,000 words with the first other word that comes to mind and then uses both words in a sentence. This process is videotaped, to provide images needed to create animated computer graphics of the person speaking any words or sentences.


It makes sense to work on means for recording human personalities before we have worked out all the details of resurrecting them, because many people may not survive until the entire technological system has been perfected. But much research is currently in progress on means for archiving and playing back aspects of a human being.

Several projects of the federally-funded Digital Library Initiative (DLI) are developing needed technology, incidentally to other work. Notable is the Informedia project by a team at Carnegie-Mellon University headed by Howard D. Wactlar. In its first stage, this multimedia DL developed automatic methods to index, search, and summarize audio-visual material, such as television news and science programs.

One application of such technology is the virtual interview. Suppose you are a student doing a report on President John F. Kennedy's policies. Either by speaking into a microphone or typing on a keyboard, you ask him a question. The DL's computer system searches its archives for everything he wrote or said that might be an answer to your question, and presents the material to you. Taken just a few steps forward, adding an "avatar" computer-animated image of a person, such a system would allow you to carry on a virtual conversation with someone who was deceased but had earlier contributed much verbal material to the DL.

A new phase of Informedia, sponsored by the Defense Advanced Projects Agency, is Experience on Demand. This "develops tools, techniques and systems allowing people to capture a record of their experiences unobtrusively, and share them in collaborative settings spanning both time and space . . . Personal EOD units record audio, video, Global Positioning System (GPS) spatial information, and other sensory data, which can be annotated by human participants." Two obvious military uses are battlefield reconnaissance in which the EOD unit worn by a scout records what he sees and hears, and training in which an expert goes through the actions and environment that a neophyte must learn about.

The most impressive project to record human experience is the privately funded Survivors of the Shoah Visual History Foundation. This magnificent and expensive effort was established by director Steven Spielberg in 1994 to videotape the reminiscences of survivors of the European Holocaust. At latest count, interviews had been completed in 32 languages with over 52,000 survivors of the concentration camps. It would take more than thirteen years to watch the entire collection straight through. Advanced DL techniques will make it possible to link all testimonies that concern the same topics, and to navigate from record to record in a myriad of enlightening ways.

The Shoah project is already confronting some of the ethical issues that future archives of human personalities will have to face. For example, it is necessary to protect the privacy and integrity of the interviews. Malicious people could misuse the pictures, voices and personal information in many hideous ways, if they could readily be downloaded from the Internet. Therefore, the current plan is to use secure fiberoptic computer networks to provide the material to protected sites, such as the United States Holocaust Memorial Museum.

Imagine that we record your personality and life's experience, using a variety of social-science and computer methods like those pioneered by The Question Factory, Experience on Demand, and Survivors of the Shoah Visual History Foundation. The few dozen terabytes of your data could be stored simultaneously in several high-security archives. But a working copy could be in custody of your great-grandchild or someone of the future who simply wants you for a virtual friend.

Even with today's primitive technology, your voice could speak again, advising your future friend about prosaic things like what to have for dinner, helping him or her through a rough time of life by sharing how you have experienced and dealt with disappointment, and suggesting ways that he or she might build a better future.

A politically radical but technically easy option would allow you to vote posthumously in elections of your nation, community, or organization. Today, you would answer several thousand questions about political issues, policies, and your general philosophy of life.

Long after your demise, a random sample of the population would answer these same questions plus new questions that were part of a referendum on some key decisions of the day. Statistical analysis of the future respondents' answers would make it possible to predict how you would answer the new referendum questions, and your vote could be included with theirs.

Any innovation that overturns prevailing social norms will meet opposition, but often innovations can get started in especially conducive contexts, and spread out from there. For example, opponents might argue that only living people should vote, because the dead have no interest in how society is run. Taken to the extreme, this argument implies that old people, who will die before the full effect of new laws has been felt, should have only fractional votes, whereas young people with many years to live under the regime should have full votes. Posthumous voting, however, could get started in voluntary organizations, before gradually invading the society's political process.

For example, imagine that an elderly rich person named Bill Getty wanted to leave a billion dollars in a foundation for struggling artists. A scientifically designed art appreciation test would measure his tastes and aesthetic sensitivities. After his death, every year hundreds of artists would submit works of art that would be displayed to the public. Visitors to the exhibition would take the same art appreciation test that Bill Getty had, and they would rate each of the artists. A statistical technique such as multiple regression analysis would produce an equation, based both on Bill's test scores and those of the given year's exhibition visitors, that would estimate which artists Bill would have wanted to support, and they would win grants from his foundation. Because the money belonged to Bill in the first place, no one could complain about the fact that his tastes continued to determine the grants made by his foundation after his death. Once it was established in the special case of individual legacies, posthumous voting could gradually be adopted by university clubs, churches and other private organizations, before being tried out with political districts.

Today it is also technically possible to combine archived aspects of several people in a virtual-reality simulation of a community, although with nothing like the fidelity Arthur C. Clarke imagined the distant future could achieve. The Valley of the Shadow is a website commemorating two communities of the American Civil War, for example. In a few years, there may be online virtual historical communities analogous to Williamsburg, Virginia, and Mystic Seaport, Connecticut. Aspects of your personality could be put to work there, in the form of what computer scientists call an "intelligent agent," for the benefit of future students and tourists. The simulation could be kept running all the time, regardless of whether there were any living visitors, and your agent could debate with the others whether their lives were real or not.


Questionnaires and computerized databases may lack the drama associated with cryonics, cloning, and brain scanning. Answering questions in the comfort of your home is less exciting than plunging your severed head into a vat of liquid nitrogen, or feeding slices of your brain into a fax machine. But gentle technology may sometimes be most effective.

Already, it is possible to place a deceased person's record in a computer database that can participate in social life by advising living people and serving as a virtual friend. In time, it should be possible to incorporate a recorded personality in a robot - for example, a space probe or a cyborg astronaut helping to colonize the galaxy. Eventually, it may be possible to resurrect the personality in a cloned body that is identical to the original, whether on this world or on a distant planet that has been terraformed to make it livable.

To me, the most attractive feature of this approach is that we can begin to record ourselves today, without waiting for radical scientific breakthroughs, and that any of us can contribute to development of the technology. The most severe question is whether we would consider this to be real immortality, and many people would say that it was not.

From one perspective, even a perfect duplicate of you, capable of self-awareness and of impersonating you in public, is not really you. William F. Temple's 1951 novel, Four-Sided Triangle, concerns the duplication of a woman so that the two men who love her will each have a copy, leading of course to tragic results. If the woman had put her copy into cryonic suspension, we would still be reluctant to say she had found a way to preserve herself - her very own unique self.

We already possess technology that can allow aspects of your personality to influence the world in a dynamic manner, even after you are no longer living in it. This falls short of true immortality, because you (as conventionally defined) will not be conscious of it. Your evaluation of the possibilities for future cybernetic immortality will depend, therefore, not merely upon your estimate of the technical possibilities but also upon your personal conception of yourself.



Ray Kurzweil. The Age of Spiritual Machines: When Computers Exceed Human Intelligence. New York: Viking, 1999, see pp. 6, 122-123.


Robert C. W. Ettinger, "A Matter of Life and Death," Analog, June 1979, pp. 67-75.

H. G. Stratmann, "Suspended Animation: The Cold Facts," Analog, April 2000, pp. 43-55.

Ancient DNA:

Matthias Krings, Anne Stone, Ralf W. Schmitz, Heike Krainitzki, Mark Stoneking, and Svante Paabo, "Neandertal DNA Sequences and the Origin of Modern Humans," Cell, (1997) 90:19-30.


Zita A. Peterlin, James Kozloski, Bu-Qing Mao, Areti Tsiola, and Rafael Yuste, "Optical Probing of Neuronal Circuits with Calcium Indicators," Proceedings of the National Academy of Sciences, 97 C7): 3619-3624, March 28, 2000.

Doron Shoham, Daniel E. Glaser, Amos Arieli, Tal Kenet, Chaipi Wijnbergen, Yuval Toledo, Rina Hildesheim, and Amiram Grinvald, "Imaging Cortical Dynamics and High Spatial and Temporal Resolution with Novel Blue Voltage-Sensitive Dyes," Neuron, vol. 24, pp. 791-801, December 1999.

Social-Psychological Measures:

William Sims Bainbridge, Survey Research: A Computer-Assisted Introduction. Belmont, California: Wadsworth, 1989.

Richard Christie and Florence L. Gets, Studies in Machiavellianism. New York: Academic Press, 1970.

Bert Arthur Goldman et al., Directory of Unpublished Experimental Mental Measures. Washington, DC: American Psychological Association, 7 volumes 1995-1997.


Center for Reproduction of Endangered Species, Zoological Society of San Diego

Coriell Cell Repositories, Coriell Institute for Medical Research

Informedia Experience-on-Demand Project

The Question Factory: http://www. erols.com/bainbri/qf.htm (obsolete URL)

Survivors of the Shoah Visual History Foundation

The Valley of the Shadow