2001 : WHAT QUESTIONS HAVE DISAPPEARED?

On April 8, 1966, the cover of Time Magazine asked "Is God Dead?" in bold red letters on a jet black background. This is an arresting question that no one asks anymore, but back in 1996 it was a hot issue that received serious comment. In 1882 Friedrich Nietzsche in The Gay Science had a character called "the madman" running through the marketplace shouting "God is dead!", but in the book, no one took the madman seriously.

The Time Magazine article reported that a group of young theologians calling themselves Christian atheists, led by Thomas J. J. Altizer at Emory University, had claimed God was dead. This hit a cultural nerve and in an appearance on "The Merv Griffin Show" Altizer was greeted by shouts of "Kill him! Kill him!" Today Altizer continues to develop an increasingly apocalyptic theology but has not received a grant or much attention since 1966.

The lesson here is that the impact of a question very much depends on the cultural moment. Questions disappear not because they are answered but because they are no longer interesting.

TERRENCE J. SEJNOWSKI, a pioneer in Computational Neurobiology, is regarded by many as one of the world's most foremost theoretical brain scientists. In 1988, he moved from Johns Hopkins University to the Salk Institute, where he is a Howard Hughes Medical Investigator and the director of the Computational Neurobiology Laboratory. In addition to co-authoring The Computational Brain,he has published over 250 scientific articles.

I do not, of course, mean any particular Great Central Theory. I am referring to the once-pervasive habit of relating everything that had human scale — Chinese history, the Odyssey, your mother's fear of heights — to an all-explaining principle. This principle was set forth in a short shelf of classic works and then worked to a fine filigree by close-minded people masquerading as open-minded people. The precise Great Central Theory might be, as it was in my childhood milieu, the theories of Freud. It might be Marx. It might be Levi-Strauss or, more recently, Foucault. At the turn of the last century, there was a Darwinist version going, promulgated by Francis Galton, Herbert Spencer and their ilk.

These monolithic growths had begun, I suppose, as the answers to specific questions, but then they metastasized; their adherents would expect the great central theory to answer any question. Commitment to a Great Central Theory thus became more a religious act than an intellectual one. And, as with all religions, the worldview of the devout crept into popular culture. (When I was in high school we'd say So-and-So was really anal about his locker or that What's-his-name's parents were really bourgeois.) For decades, this was what intellectual life appeared to be: Commit to an overarching explanation, relate it to everything you experienced, defend it against infidels. Die disillusioned, or, worse, die smug.

So why has this sort of question vanished? My guess is that, broadly speaking, it was a product of the Manichean worldview of the last century. Depression, dictators, war, genocide, nuclear terror — all of these lend themselves to a Yes-or-No, With-Us-or-With-Them, Federation vs. Klingons mindset. We were, to put it simply, all a little paranoid. And paranoids love a Great Key: Use this and see the single underlying cause for what seems to be unrelated and random!

Nowadays the world, though no less dangerous, seems to demand attention to the seperateness of things, the distinctiveness of questions. ''Theories of everything'' are terms physicists use to explain their near-theological concerns, but at the human scale most people care about, where we ask questions like ''why can't we dump the Electoral College?'' or ''How come Mom likes my sister better?'', the Great Central Theory question has vanished with the black-or-white arrangement of the human world.

What's next?

Three possibilities.

One, some new Great Central Theory slouches in; some of the Darwinians think they've got the candidate, and they certainly evince signs of quasi-religious commitment. (For example, as a Freudian would say you doubted Freud because of your neuroses, I have heard Darwinians say I doubted their theories because of an evolved predisposition not to believe the truth. I call this quasi-religious because this move makes the theory impregnable to evidence or new ideas.)

Two, the notion that overarching theory is impossible becomes, itself, a new dogma. I lean toward this prejudice myself but I recognize its dangers. An intellectual life that was all boutiques could be, in its way, as stultifying as a giant one-product factory.

Three, we learn from the mistakes of the last two centuries and insist that our answers always match our questions, and that the distinction between theory and religious belief be maintained.

DAVID BERREBY'S writing about science and culture has appeared in The New York Times Magazine, The New Republic, Slate, The Sciences and many other publications.

Despite Seattle and the French farmers, free market advocates of globalization have largely won — even CHina is signing up to be a major player in the international trading and growth-oriented global political economy. So it is rare to hear this question anymore, even from so-called "enterprise institutes" dedicated to protecting property rights.

The problem is, what has been won?? My concern is not with the question no-longer asked in this context, but rather with the companion question not often enough asked: "Is there any such thing as a free market"?

To be sure, markets are generally efficient ways of allocating resources and accomplishing economic goals. However, markets are notorious for leaving out much of what people really value. In different words, the market price of doing business simply excludes much of the full costs or benefits of doing business because many effects aren't measured in traditional monetary units. For example, the cost of a ton of coal isn't just the extraction costs plus transportation costs plus profit, but also real expenses to real people (or real creatures) who happen to be external to the energy market. Such "externalities" are very real to coastal dwellers trying to cope with sea level rises likely to be induced from the global warming driven by massive coal burning.

I recall a discussion at the recent international negotiations to limit emissions of greenhouse gasses in which a chieftain from the tiny Pacific island of Kiribati was being told by an OPEC supporter opposed to international controls on emissions from fossil fuels that the summed economies of all the small island states were only a trivial fraction of the global GDP, and thus even if sea level rise were to drive them out of national existence, this was "not sufficient reason to hold back to economic progress of the planet by constricting the free use of energy markets".

"We are not ungenerous", he said, so in the "unlikely event" that you were a victim of sea level rise, "we'll just pay to relocate all of you and your people to even better homes and jobs than you have now", and this, he went on, will be much cheaper than to "halt industrial growth" (THis isn't the forum to refute the nonsense that controls on emissions will halt industrial growth.) After hearing this offer, the aging and stately chieftain paused, scratched his flowing hair, politely thanked the OPEC man for his thoughtfulness and simply said, "we may be able to move, but what do I do with the buried bones of my grandfather?"

Economists refer to the units of value in cost-benefit analyses as "numeraires" — dollars per ton carbon emitted in the climate example, is the numeraire of choice for "free market" advocates. But what of lives lost per ton of emissions from intensified hurricanes, or species driven off mountain tops to extinction per ton, or heritage sites lost per ton?? Or what if global GDP indeed goes up fastest by free markets but 25% of the world gets left further behind as globally economically efficient markets expand? Is equity a legitimate numeraire too?

Therefore, while market systems seem indeed to have triumphed, it is time to phase in a new, multi-part question: "How can free markets be adjusted to value what is left out of private cost-benefit calculus but represents real value so we can get the price signals in markets to reflect all the costs and benefits to society across all the numeraires, and not simply have market prices rigged to preserve the status quo in which monetary costs to private parties are the primary condition?"

I hope the new US president soon transcends all that obligatory free market rhetoric of the campaign and learns much more about what constitutes a full market price. It is very likely he'll get an earful as he jetsets about the planet in Air Force 1 catching up on the landscapes — political and physical — of the vastly diverse countries in the world that it is time for him to visit. Many world leaders are quite worried about just what we will have won as currently defined free markets triumph.

STEPHEN H. SCHNEIDER is Professor in the Biological Sciences Department at Stanford University and the Former Department Director and Head of Advanced Study Project at the National Center for Atmospheric Research Boulder. He is internationally recognized as one of the world's leading experts in atmospheric research and its implications for environment and society. Dr. Schneider's books include The Genesis Strategy: Climate Change and Global Survival; The Coevolution Of Climate and Life and Global Warming: Are We Entering The Greenhouse Century?; and Laboratory Earth

My vanished question is:"'How does a slide rule work?"' Slide rules were once ubiquitous in labs, classrooms, and the pockets of engineers. They are now as common as dinosaurs; totally replaced by electronic calulators and computers. The interesting question to ponder is: what is it that in the future will do to computers what computers did to slide rules?

JOHN BARROW is a physicist at Cambridge University.. He is the author of The World Within the World, Pi in the Sky, Theories of Everything, The Origins of the Universe (Science Masters Series),The Left Hand of Creation, The Artful Universe, and Impossibility: The Limits of Science and the Science of Limits.

This question was long considered metaphysical, briefly became a scientific question, and has now disappeared again. Victorian intellectuals such as Frederic Myers, Henry Sidgwick and Edmund Gurney founded the Society for Psychical Research in 1882 partly because they realised that the dramatic claims of spiritualist mediums could be empirically tested. They hoped to prove "survival" and thus overturn the growing materialism of the day. Some,
like Faraday, convinced themselves by experiment that the claims were false, and lost interest. Others, like Myers, devoted their entire lives to ultimately inconclusive research. The Society continues to this day, but survival research has all but ceased.

I suggest that no one asks the question any more because the answer seems too obvious. To most scientists it is obviously "No", while to most New Agers and religious people it is obviously "Yes". But perhaps we should. The answer may be obvious (it's "No" — I'm an unreligious scientist) but its implications for living our lives and dealing compassionately with other people are profound.

SUSAN BLACKMORE is a psychologist and ex-parapsychologist, who — when she found no evidence of psychic phenomena — turned her attention to why people believe in them. She is author of several skeptical books on the paranormal and, more recently, The Meme Machine.

Different people on the Edge list seem to have chosen to understand 'questions that have disappeared' in three very different senses:

1. Questions that were once popular but have now been answered 
2. Questions that should never have been asked in the first place 
3. Questions that have disappeared although they never received a satisfactory answer.

This third meaning is, I suspect, the one intended by the organizer of the forum.  It is the most interesting of the three since it suggests real science that we should now be doing, rather than just raking over the historical coals.

The three meanings are too disparate to bring together easily, but I'll try. The popular question 'Has there been enough time for evolution to take place?'  can now confidently be answered in the affirmative.  It should never have been put in the first place since, self-evidently, we are here. But what is more interesting is that the real question that faces us is almost the exact opposite.  Why is evolution so slow, given that natural selection is so powerful?   Far from there being too little time for evolution to play with, there seems to be too much.

Ledyard Stebbins did a theoretical calculation about an extremely weak selection pressure, acting on a population of mouse-sized animals to favor the largest individuals.  His hypothetical selection pressure was so weak as to be below the threshold of detectability in field sampling studies.  Yet the calculated time to evolve elephant-sized descendants from mouse-sized ancestors was only a few tens of thousands of generations: too short to be detected under most circumstances in the fossil record.  To exaggerate somewhat, evolution could be yo-yo-ing from mouse to elephant, and back again, so fast that the changes could seem instantaneous in the fossil record.

Worse, Stebbins's calculation assumed an exceedingly weak selection pressure.  The real selection pressures measured in the field by Ford and his colleagues on lepidoptera and snails, by Endler and his colleagues on guppies, and by the Grants and their colleagues on the Galapagos finches, are orders of magnitude stronger.  If we fed into the Stebbins calculation a selection pressure as strong as the Grants have measured in the field, it is positively worrying to contemplate how fast evolution could go.  The same conclusion is indirectly suggested by domestic breeding.  We have gone from wolf to Yorkshire terrier in a few centuries, and could presumably go back to something like a wolf in as short a time.

It is indeed the case that evolution on the Galapagos archipelago has been pretty fast, though still nothing like as fast as the measured selection pressures might project.  The islands have been in existence for five million years at the outside, and the whole of their famous endemic fauna has evolved during that time.  But even the Galapagos islands are old compared to Lake Victoria.  In the less than one million years of the lake's brief lifetime, more than 170 species of the genus Haplochromis alone have evolved.

Yet the Coelacanth Latimeria, and the three genera of lungfish, have scarcely changed in hundreds of millions of years.  Surviving Lingula ('lamp shells') are classified in the same genus as their ancestors of 400 million years ago, and could conceivably interbreed with them if introduced through a time machine.  The question that still faces us is this.  How can evolution be both so fast and so leadenly slow?  How can there be so much variance in rates of evolution?  Is stasis just due to stabilizing selection and lack of directional selection?  Or is there something remarkably special going on in the (non) evolution of living fossils?  As William Blake might have written to a coelacanth: Did he who made the haplochromids make thee?

RICHARD DAWKINS is an evolutionary biologist and the Charles Simonyi Professor For The Understanding Of Science at Oxford University; Fellow of New College; author of The Selfish Gene, The Extended Phenotype , The Blind Watchmaker, River out of Eden (ScienceMasters Series), Climbing Mount Improbable, and Unweaving the Rainbow.

Contemporary linguists tend to assume in their work that subordinate clauses, such as "The boy that I saw yesterday" or "I knew what happened when she came down the steps", are an integral part of the innate linguistic endowment, and/or central features of "human speech" writ large. Most laymen would assume the same thing. However, the fact is that when we analyze a great many strictly spoken languages with no written tradition, subordinate clauses are rare to nonexistent. In many Native American languages, for example, the only way to express something like the men who were members is a clause which parses approximately as "The 'membering' men"; the facts are similar in thousands of other languages largely used orally.

In fact, even in earlier documents in today's "tall building" literary languages, one generally finds a preference for stringing simple main clauses together —she came down the steps, and I knew what happened rather than embedding them in one another along the lines of when she came down the steps, I knew what happened. The guilty sense we often have when reading English of the first half of the last millennium that the writing is stylistically somewhat "clunky" is due largely to the marginality of the subordinate clause: here is Thomas Malory in the late fifteenth century:

And thenne they putte on their helmes and departed 
and recommaunded them all wholly unto the Quene
and there was wepynge and grete sorowe
Thenne the Quene departed in to her chamber
and helde her
that no man shold perceyue here grete sorowes

Early Russian parses similarly, and crucially, so do the Hebrew Bible and the Greek of Homer.

At the time that these documents were written, writing conventions had yet to develop, and thus written language hewed closer to the way language is actually spoken on the ground. Over time, subordinate clauses, a sometime thing in speech, were developed as central features in written speech, their economy being aesthetically pleasing, and more easily manipulated via the conscious activity of writing than the spontaneous "on-line" activity of speaking. Educated people, exposed richly to written speech via education, tended to incorporate the subordinate clause mania into their spoken varieties. Hence today we think of subordinate clauses as "English", as the French do "French", and so on — even though if we listen to a tape recording of ourselves speaking casually, even we tend to embrace main clauses strung together in favor of the layered sentential constructions of Cicero.

But the "natural" state of language persists in the many which have had no written tradition. In the 1800s, various linguists casually speculated as to whether subordinate clauses were largely artifactual rather than integral to human language, with one (Karl Brugmann) even going as far as to assert that originally, humans spoke only with main clauses.

Today, however, linguistics operates under the sway of our enlightened valuation of "undeveloped" cultures, which has, healthily, included an acknowledgment of the fact that the languages of "primitive" peoples are as richly complex as written Western languages. (In fact, the more National Geographic the culture, the more fearsomely complex the language tends to be overall.) However, this sense has discouraged most linguists from treading into the realm of noting that one aspect of "complexity", subordinate clauses, is in fact not central to expression in unwritten languages and is most copiously represented in languages with a long written tradition. In general, the idea that First World written languages might exhibit certain complexities atypical of languages spoken by preliterate cultures has largely been tacitly taboo for decades in linguistics, generally only treated in passing in obscure venues.

The problem is that this could be argued to bode ill for investigations of the precise nature of Universal Grammar, which will certainly require a rigorous separation of the cultural and contingent from the encoded.

JOHN H. MCWHORTER is Assistant Professor of Linguistics at the University of California at Berkeley. He taught at Cornell University before entering his current position at Berkeley. He specializes in pidgin and creole languages, particularly of the Caribbean, and is the author of Toward a New Model of Creole Genesisand The Word on the Street : Fact and Fable About American English. He also teaches black musical theater history at Berkeley and is currently writing a musical biography of Adam Clayton Powell, Jr.

One question that has almost disappeared, but which I think should not is the old question about whether our categories of reality are discovered or constructed. In medieval times this was the debate about realism versus nominalism. Earlier this century the question flared up again in the debates about the relativistic nature of knowledge and has more recently given rise to the whole "science wars" debacle, but reading the science press today one would think the question had been finally resolved — on the side of realism. Reading the science press now one gets a strong impression that for most scientists our categories of reality are Platonic, almost God-given entities just waiting for the right mind to uncover them. This hard-nosed realist trend is evident across the spectrum of the sciences, but is particularly strong in physics, where the search is currently on for the supposed "ultimate" category of reality — strings being a favored candidate. What gets lost in all this is any analysis of the role that language plays in our pictures of reality. We literally cannot see things that we have no words for. As Einstein once said "we can only see what our theories allow us to see." I would argue that the question of what role language plays in shaping our picture of reality is one of the most critical questions in science today — and one that should be back on the agenda of every thoughtful scientiist.

Just one example should suffice to illustrate what is at stake here: MIT philosopher of science Evelyn Fox Keller has shown in her book Secrets of Life, Secrets of Death (and elsewhere) the primary role played by language in shaping theories of genetics. Earlier this century physicists like Max Delbruck and Erwin Schrodinger started to have a philosophical impact on the biological sciences, which henceforth became increasingly "physicized." Just as atoms were seen as the ultimate constituents of matter so genes came to be seen as the ultimate constituents of life — the entities in which all power and control over living organisms resided. What this metaphor of the "master molecule" obscured was th role played by the cytoplasm in regulating the function and activation of genes. For half a century study of the cytoplasm was virtually ignored because genetics were so fixed on the idea of the gene as the "master colecule." Sure much good work on genetics was done, but important areas of biological function were also ignored. And are still being ignored by the current "master molecule" camp — the evolutionary psychologists, who cannot seem to see anything but through the prism of genes.

Scientists (like all other humans) can only see reality as their language and their metaphors allow them to see it. This is not to say that scientists "make up" their discoveries, only to point out that language plays a critical role in shaping the way we categorize, and hence theorize, the world around us. Revolutions in science are not just the result of revolutions in the laboratory or at theorists blackboards, they are also linguistic revoluttions. Think of words like inertia, energy, momentum — words which did not have any scientific meaning before the seventeenth century. Or words like quantum, spin, charm and strange, which have only had scientific meaning science the quantum revolution of the early twentieth century. Categories of reality are not merely discovered — they are also constructed by the words we use. Understanding more deeply the interplay between the physical world and human language is, I believe, one of the major tasks for the future of science.

MARGARET WERTHEIM is the author of Pythagoras Trousers, a history of the relationship between physics and religion; and The Pearly Gates of Cyberspace: A History of Space from Dante to the Internet. She is a research associate to the American Museum of Natural History in NY and a fellow of the Los Angeles Institute for the Humanities. She is currently working on a documentary about "outsider physics."

Heavens, I take a couple of days off from reading email over Christmas and when I next log on already there are over twenty responses to the Edgequestion! Maybe the question we should all be asking is "Doesn't anyone take time off any more?"

As to questions that have disappeared, as a mathematician I hope we've seen the last of the question "Why can't girls/women do math?" With women now outnumbering men in mathematics programs in most US colleges and universities, that old wives' tale (old husbands' tale?) has surely been consigned to the garbage can. Some recent research at Brown University confirmed what most of us had long suspected: that past (and any remaining present) performance differences were based on cultural stereotyping. (The researchers found that women students performed worse at math tests when they were given in a mixed gender class than when no men were present. No communication was necessary to cause the difference. The sheer presence of men was enough.)

While I was enjoying my offline Christmas, Roger Schank already raised the other big math question: Why do we make such a big deal of math performance and of teaching math to everyone in the first place? But with the educational math wars still raging, I doubt we've
seen the last of that one!

KEITH DEVLIN is a mathematician, writer, and broadcaster living in California. His latest book is The Math Gene: How Mathematical Thinking Evolved and Why Numbers Are Like Gossip.

The road of knowledge is littered with old questions, but by their very nature, none of them stands out above all others. The diversity of thoughtful responses given on the Edge forum, which just begin to scratch the surface, illustrates how progress happens. The evolution of knowledge is a Schumpterian process of creative destruction, in which weeding out the questions that no longer merit attention is an integral part of formulating better questions that should. Forgetting is a vital part of creation.

Maxwell once worried that the second law of thermodynamics could be violated by a demon who could measure the velocity of individual particles and separate the fast ones from the slow ones, and use this to do work. Charlie Bennet showed that that this is impossible, because to make a measurement the demon has to first put her instruments in a known state.

This involves erasing information. The energy needed to do this is more than can be gained. Thus, the fact that forgetting takes work is essential to the second law of thermodynamics. Why is this relevant? As Gregory Bateson once said, the second law of thermodynamics is the reason that it is easier to mess up a room than it is to clean it. Forgetting is an essential part of the process of creating order. Asking the right questions is the most important part of the creative process. There are lots of people who are good at solving problems, fewer who are good at asking questions.

Around the time I took my qualifying examination in physics, someone showed me the test that Lord Rayleigh took when he graduated as senior wrangler from Cambridge in 1865. I would have failed it. There were no questions on thermodynamics, statistical mechanics, quantum mechanics, nuclear physics, particle physics, condensed matter, or relativity, i.e. no questions covering most of what I had learned.

However, the classical mechanics questions, which comprised most of the bets, were diabolically hard. Their solution involved techniques that are no longer taught, and that a modern physicist would have to work hard to recreate. Of course, in a field like philosophy this would not have surprised me — it just hadn't occurred to me that this was as true for physics as well. The physicists in Rayleigh's generation presumably worked just as hard, and knew just as many things. They just knew different things. After overcoming the shock of how much had seemingly been lost, I rationalized my ignorance with the belief that what I was taught was more useful than what Rayleigh was taught. Whether as a culture or as individuals, to learn new things, we have to forget old things. The notion of what is useful is constantly evolving.

The most important questions evolve through time as people understand little bits and pieces, and view them from different angles in the attempt to solve them. Each question is replaced by a new one that is (hopefully) better framed than its antecedant. Reflecting on those that have been cast aside is like sifting through flotsam on a beach, and asking what it tells us. Is there a common thread that might give us a clue to posing better questions in the future?

When we examine questions such as "What is a vital force?", "How fast is the earth moving?", "Does God exist?", "Have we seen the end of science?", "Has history ended?", "Can machines think?", there are some common threads. One is that we never really understood what these questions meant in the first place. But these questions (to varying degrees) have been useful in helping us to formulate better, more focused questions. We just have to turn loose of our pet ideas, and make a careful distinction between what we know and what we only think we know, and try to be more precise about what we are really asking.

I would be curious to hear more discussion about the common patterns and the conclusions to be drawn from the questions that have disappeared.

J. DOYNE FARMER, one of the pioneers of what has come to be called chaos theory, is McKinsey Professor, Sante Fe, Institute, and the co founder and former co-president of Prediction Company in Santa Fe, New Mexico.

Progress in the domain that Marvin Minsky once characterized as "making machines do things that would be considered intelligent if done by people" has not been as dramatic as its founders might once have hoped, but the penetration of machine cognition into everyday life (from the computer that plays chess to the computer that determines if your toast is done) has been broad and deep. We now the term "intelligent" to refer to the kind of helpful smartness embedded in such objects. So the language has shifted and the question has disappeared. But until recently, there was a tendency to limit appreciation of machine mental prowess to the realm of the cognitive. In other words, acceptance of artificial intelligence came with a certain "romantic reaction." People were willing to accept that simulated thinking might well be deemed thinking, but simulated feeling was not feeling. Simulated love could never be love.

These days, however, the realm of machine emotion has become a contested terrain. There is research in "affective computing" and in robotics which produces virtual pets and digital dolls — objects that present themselves as experiencing subjects. In artificial intelligence's "essentialist" past, researchers tried to argue that the machines they had built were "really" intelligent. In the current business of building machines that self-present as "creatures," the work of inferring emotion is left in large part to the user. The new artificial creatures are designed to push our evolutionary buttons to respond to their speech, their gestures, and their demands for nurturance by experiencing them as sentient, even emotional. And people are indeed inclined to respond to creatures they teach and nurture by caring about them, often in spite of themselves. People tell themselves that the robot dog is a program embodied in plastic, but they become fond of it all the same. They want to care for it and they want it to care for them.

In cultural terms, old questions about machine intelligence has given way to a question not about the machines but about us: What kind of relationships is it appropriate to have with a machine? It is significant that this question has become relevant in a day-to-day sense during a period of unprecedented human redefinition through genomics and psychopharmacology, fields that along with robotics, encourage us to ask not only whether machines will be able to think like people, but whether people have always thought like machines

SHERRY TURKLE is a professor of the sociology of science at MIT. She is the author of Life on the Screen: Identity in the Age of the Internet; The Second Self: Computers and the Human Spirit; and Psychoanalytic Politics: Jacques Lacan and Freud's French Revolution.

The moment of birth used to be attended by an answer to a nine-month mystery: girl or boy? Now, to anyone with the slightest curiosity and no mystical scruples, simple, non-invasive technology can provide the answer from an early stage of pregnancy. With both of our children, we chose to know the answer (in the UK about half of parents want to know), and I suspect the likelihood of the question continuing to be asked will diminish rapidly.

What's interesting is this is the first of many questions about the anticipated child that will soon not be asked. These will range from the trivial (eye colour, mature height) to the important (propensity to certain diseases and illnesses). The uneasiness many people still have about knowing the sex of the child suggests that society is vastly unprepared for the pre-birth answers to a wide range of questions.

LANCE KNOBEL is a managing director of Vesta Group, an Internet and wireless investment company based in London. He was formerly head of the programme of the World Economic Forum's Annual Meeting in Davos and Editor-in-Chief of World Link.

The ubiquity of upscale coffee houses has eliminated the need to ask "Where can I get a cup of coffee?" But I suspect that the question "What questions have disappeared?" is meant to elicit even deeper and [perhaps] more meaningful responses.

The coffee house glut has been accompanied — although with no necessarily causal link — by an avalanche of information [or, at least, of data] and in the rush to obtain [or "to access" — groan] that information we’ve stopped asking "What does it all mean?" It is as though raw data, in and of itself, has real value, indeed all of the value, and thus there is no need to stop, to assimilate, to ponder. We grasp for faster computers, greater bandwidth, non-stop connectivity. We put computers in every classroom, rewire schools. But, with the exception of a great deal of concern about the business and marketing uses of the new "information age," we pay precious little attention to how the information can be used to change, or improve, our lives, nor do we seem to take the time to slow down and deliberate upon its meaning.

We wire the schools, but never ask what all those computers in classrooms will be used for, or whether teachers know what to do with them, or whether we can devise ways to employ the technology to help people learn in new or better ways. We get cable modems, or high-speed telephone lines, but don’t think about what we can do with them beyond getting more information faster. [Really, does being able to watch the trailer for "Chicken Run" in a 2-inch square window on the computer screen after a several minute long download, constitute a major advance — and if we could cut the download time to several seconds, would that qualify?]

Most insidious, I think, is that the rush to get more information faster almost forces people to avoid the act of thinking. Why stop and try to make sense of the information we’ve obtained when we can click on that icon and get still more data? And more.

RAPHAEL KASPER, a physicist, is Associate Vice Provost for Research at Columbia University and was Associate Director of the Superconducting Super Collider Laboratory.

This can be elaborated by the following anecdote, from an interview (2.99) with Herbert York:

"Donald Hornig, who was head of PSAC [President's Science Advisory Committee, during the Johnson Administration] was not imaginative. I can give you an example of this. I was very enthusiastic about getting a picture of the other side of the moon. And there were various ways of doing it, sooner or later. And I argued with Hornig about it and he said, 'Why? It looks just like this side.' And it turned out it didn't. But nevertheless, that was it, and that's the real Hornig. 'Why are you so enthused about the other side of the moon? The other side of the moon looks just like this side, why would you be so interested to see it?'"

GEORGE DYSON, a historian among futurists, has been excavating the history and prehistory of the digital revolution going back 300 years. His most recent book is Darwin Among the Machines.

"What Questions Have Disappeared...And Why?" Funny you should ask that. "And why? " could itself be the most important question that has disappeared from many fields.

"And why?": in other words, "what is the explanation for what we see happening?" "What is it in reality that brings about the outcome that we predict?" Whenever we fail to take that question seriously enough, we are blinded to gaps in our favoured explanation. And so, when we use that explanation to interpret regularities that we may observe, instead of understanding that the explanation was an assumption in our analysis, we regard it as the inescapable implication of our observations.

"I just can't feel myself split", complained Bryce DeWitt when he first encountered the many-universes interpretation of quantum theory. Then Hugh Everett convinced him that this was the same circular reasoning that Galileo rejected when he explained how the Earth can be in motion even though we observe it to be at rest. The point is, both theories are consistent with that observation. Thanks to Everett, DeWitt and others, the "and why" question began gradually to return to quantum theory, whence it had largely disappeared during the 1930s. I believe that its absence did great harm both in impeding progress and in encouraging all sorts of mystical fads and pseudo-science. But elsewhere, especially in the human philosophies (generally known as social sciences), it is still largely missing. Although behaviourism — the principled refusal to ask "and why?" — is no longer dominant as an explicit ideology, it is still widespread as a psychological attitude in the human philosophies.

Suppose you identified a gene G, and a human behaviour B, and you undertook a study with 1000 randomly chosen people, and the result was that of the 500 people who had G in their genome, 499 did B, while of the 500 who lacked G, 499 failed to do B. You'd conclude, wouldn't you, that G is the predominant cause of B? Obviously there must be other mechanisms involved, but they have little influence on whether a person does B or not. You'd inform the press that all those once-trendy theories that tried to explain B through people's upbringing or culture, or attributed it to the exercise of free will or the logic of the situation or any combination of such factors — were just wrong. You've proved that when people choose to do B, they are at the very least responding to a powerful influence from their genes. And if someone points out that your results are perfectly consistent with B being 100% caused by something other than G (or any other gene), or with G exerting an influence in the direction of not doing B, you will shrug momentarily, and then forget that possibility. Won't you?

DAVID DEUTSCH's research in quantum physics has been influential and highly acclaimed. His papers on quantum computation laid the foundations for that field, breaking new ground in the theory of computation as well as physics, and have triggered an explosion of research efforts worldwide. He is a member of the Centre for Quantum Computation at the Clarendon Laboratory, Oxford University and the author of The Fabric of Reality.

My colleagues in the fashionable fields of string theory and quantum gravity advertise themselves as searching desperately for the 'Theory of Everything", while their experimental colleagues are gravid with the "God Particle", the marvelous Higgson which is the somewhat misattributed source of all mass. (They are also after an understanding of the earliest few microseconds of the Big Bang.) As Bill Clinton might remark, it depends on what the meaning of "everything" is. To these savants, "everything" means a list of some two dozen numbers which are the parameters of the Standard Model. This is a set of equations which already exists and does describe very well what you and I would be willing to settle for as "everything". This is why, following Bob Laughlin, I make the distinction between "everything" and "every thing". Every thing that you and I have encountered in our real lives, or are likely to interact with in the future, is no longer outside of the realm of a physics which is transparent to us: relativity, special and general; electromagnetism; the quantum theory of ordinary, usually condensed, matter; and, for a few remote phenomena, hopefully rare here on earth, our almost equally cut-and-dried understanding of nuclear physics. [Two parenthetic remarks: 1) I don't mention statistical mechanics only because it is a powerful technique, not a body of facts; 2) our colleagues have done only a sloppy job so far of deriving nuclear physics from the Standard Model, but no one really doubts that they can.]

I am not arguing that the search for the meaning of those two dozen parameters isn't exciting, interesting, and worthwhile: yes, it's not boring to wonder why the electron is so much lighter than the proton, or why the proton is stable at least for another 35 powers of ten years, or whether quintessence exists. But learning why can have no real effect on our lives, spiritually inspiring as it would indeed be, even to a hardened old atheist like myself.

When I was learning physics, half a century ago, the motivation for much of what was being done was still "is quantum theory really right?" Not just QED, though the solution of that was important, but there were still great mysteries in the behavior of ordinary matter--like superconductivity, for instance. It was only some twenty years later that I woke up to the fact that the battle had been won, probably long before, and that my motivation was no longer to test the underlying equations and ideas, but to understand what is going on. Within the same few years , the molecular biology pioneers convinced us we needed no mysterious "life force" to bring all of life under the same umbrella. Revolutions in geology, in astrophysics, and the remarkable success of the Standard Model in sorting out the fundamental forces and fields, leave us in the enviable position I described above: given any problematic phenomenon, we know where to start, at least. And nothing uncovered in string theory or quantum gravity will make any difference to that starting point.

Is this Horgan's End of Science? Absolutely not. It's just that the most exciting frontier of science no longer lies at the somewhat sophomoric — or quasi-religious — level of the most "fundamental" questions of "what are we made of?" and the like; what needs to be asked is "how did all this delightful complexity arise from the stark simplicity of the fundamental theory?" We have the theory of every thing in any field of science you care to name, and that's about as far as it gets us. If you like, science is now almost universally at the "software" level; the fundamental physicists have given us all the hardware we need, but that doesn't solve the problem, in physics as in every other field. It's a different game, probably a much harder one in fact, as it has often been in the past; but the game is only begun. 

PHILIP W. ANDERSON is a Nobel laureate physicist at Princeton and one of the leading theorists on superconductivity. He is the author of A Career in Theoretical Physics, and Economy as a Complex Evolving System.

The sudden increase in digital information, or bits, in our everyday lives has destroyed any question of permanence or scarcity of those bits. Just consider the example of e-mail.

Years ago when you first got online, you were excited to get e-mail, right? So every day, the big question when you logged in was, Will I have any e-mail? The chirpy announcement that "You've got mail!" actually meant something, since sometimes you didn't have mail.

Today there's no question. There's no such thing as no mail. You don't have to ask; you DO have mail. If it's not the mail you want (from friends or family), it's work-related mail or, worse, spam. Our inboxes may soon be so flooded with spam that we look for entirely different ways to use e-mail.

The death of that question, "Do I have e-mail?" has brought us a new, more interesting question as a result: "What do I do with all this e-mail?" More generally, what do we do with all these bits(e-mail, wireless messages, websites, Palm Pilot files, Napster downloads)? This is the question that will define our relationship with digital technology in coming years.

MARK HURST, founder of Internet consulting firm Creative Good, is widely credited for popularizing the term "customer experience" and the methodology around it. Hurst has worked since the birth of the Web to make Internet technology easier and more relevant to its "average" users. In 1999, InfoWorld magazine named Hurst "Netrepreneur of the Year", saying that "Mark Hurst has done more than any other individual to make Web-commerce sites easier to use." Over 39,000 people subscribe to his Good Experience newsletter, available for free at goodexperience.com or update@goodexperie nce.com.

Is enlightenment a myth or a reality? I mean the enlightenment of the east, not west, the state of supreme mystical awareness also known as nirvana, satori, cosmic consciousnesss, awakening. Enlightenment is the telos of the great Eastern religions, Buddhism and Hinduism, and it crops up occasionally in western religions, too, although in a more marginal fashion. Enlightenment once preoccupied such prominent western intellectuals as William James, Aldous Huxley and Joseph Campbell, and there was a surge of scientific interest in mysticism in the 1960’s and 1970’s. Then mysticism became tainted by its association with the human potential and New Age movements and the psychedelic counterculture, and for the last few decades it has for the most part been banished from serious scientific and intellectual discourse. Recently a few scholars have written excellent books that examine mysticism in the light of modern psychology and neuroscience — Zen and the Brain by the neurologist James Austin; Mysticism, Mind, Consciousness by the philosopher Robert Forman; The Mystical Mind by the late psychiatrist Eugene d'Aquili and the radiologist Andrew Newberg — but their work has received scant attention in the scientific mainstream. My impression is that many scientists are privately fascinated by mysticism but fear being branded as fuzzy-headed by disclosing their interest. If more scientists revealed their interest in mystical consciousness, perhaps it could become a legitimate subject for investigation once again.

JOHN HORGAN is a freelance writer and author of The End of Science and The Undiscovered Mind. A senior writer at Scientific American from 1986 to 1997, he has also written for the New York Times, Washington Post, New Republic, Slate, London Times, Times Literary Supplement and other publications.

Such a simple question. Many of you might think "Has that question really disappeared?" Some questions disappear for ever because they have been answered. Some questions go extinct because they were bad questions to begin with. But there are others that appear to vanish but then we find that they are back with us again in a slightly different guise. They are questions that are just too close to our hearts for us to let them die completely. 

For millennia, human superiority was taken for granted. From the lowest forms of life up to humans and then on to the angels and God, all living thing were seen as arranged in the Great Chain of Being. Ascend the chain and perfection grows. It is a hierarchical philosophy that conveniently allows for the exploitation of dumber beasts — of other species or races — as a right by their superiors. We dispose of them as God disposes of us.

The idea of human superiority should have died when Darwin came on the scene. 

Unfortunately, the full implications of what he said have been difficult to take in: there is no Great Chain of Being, no higher and no lower. All creatures have adapted effectively to their own environments in their own way. Human "smartness" is just a particular survival strategy among many others, not the top of a long ladder.

It took a surprisingly long time for scientists to grasp this. For decades, comparative psychologists tried to work out the learning abilities of different species so that they could be arranged on a single scale. Animal equivalents of intelligence tests were used and people seriously asked whether fish were smarter than birds. It took the new science of ethology, created by Nobel-prize winners Konrad Lorenz, Niko Tinbergen and Karl von Frisch, to show that each species had the abilities it needed for its own lifestyle and they could not be not arranged on a universal scale. Human smartness is no smarter than anyone else's smartness. The question should have died for good. 

Artificial intelligence researchers came along later but they too could not easily part from medieval thinking. The most important problems to tackle were agreed to be those that represented our "highest" abilities. Solve them and everything else would be easy. As a result, we have ended up with computer programs that can play chess as well as a grandmaster. But unfortunately we have none that can make a robot walk as well as a 2-year old, yet alone run like a cat. The really hard problems turn out to be those that we share with "lower" animals. 

Strangley enough, even evolutionary biologists still get caught up with the notion that humans stand at the apex of existence. There are endless books from evolutionary biologists speculating on the reasons why humans evolved such wonderful big brains, but a complete absence of those which ask if a big brains is a really useful organ to have. The evidence is far from persuasive. If you look at a wide range of organisms, those with bigger brains are generally no more successful than those with smaller brains — hey go extinct just as fast. 

Of course, it would be really nice to sample a large range of different planets where life is to be found and see if big-brained creatures do better over really long time scales (the Earth is quite a young place). Unfortunately, we cannot yet do that, although the fact that we have never been contacted by any intelligent life from older parts of the Universe suggests that it usually comes to a bad end. 

Still, as we are humans it's just so hard not to be seduced by the question "What makes us so special" which is just the same as the question above but in a different form. When you switch on a kitchen light and see a cockroach scuttle for safety you can't help seeing it as a lower form of life. Unfortunately, there are a lot more of them than there are of us and they have been around far, far longer. Cockroach philosophers doubtless entertain their six-legged friends by asking "What makes us so special".

ALUN ANDERSON is Editor-in-Chief of New Scientist.

This question was at the heart of heated debates for decades during the recently past century, and it was at the ambitious origins of the Artificial Intelligence adventure. It had profound implications not only for science, but also for philosophy, technology, business, and even theology. In the 50's and 60's, for instance, it made a lot of sense to ask the question whether one day a computer could defeat an international chess master, and if it did, it was assumed that we would learn a great deal about how human thought works. Today we know that building such a machine is possible, but the reach of the issue has dramatically changed. Nowadays not many would claim that building such a computer actually informs us in an interesting way about what human thought is and how it works. Beyond the (indeed impressive) engineering achievements involved in building such machines, we got from them little (if any) insight into the mysteries, variability, depth, plasticity, and richness of human thought. Today, the question "do computers think?" has become completely uninteresting and it has disappeared from the cutting edge academic circus, remaining mainly in the realm of pop science, Hollywood films, and video games.

And why it disappeared?

It disappeared because it was finally answered with categorical responses that stopped generating fruitful work. The question became useless and uninspiring, ... boring. What is interesting, however, is that the question disappeared with no single definitive answer! It disappeared with categorical "of-course-yes" and "of-course-not" responses. Of-course-yes people, in general motivated by a technological goal (i.e., "to design and to build something") and implicitly based on functionalist views, built their arguments on the amazing ongoing improvement in the design and development of hardware and software technologies. For them the question became uninteresting because it didn't help to design or to build anything anymore. What became relevant for of-course-yes people was mainly the engineering challenge, that is, to actually design and to build computers capable of processing algorithms in a faster, cheaper, and more flexible manner. (And also, for many, what became relevant was to build computers for human activities and purposes). Now when of-course-yes people are presented with serious problems that challenge their view, they provide the usual response: "just wait until we get better computers" (once known as the wait-until the-year-2000 argument). On the other hand there were the of-course not people, who were mainly motivated by a scientific task (i.e., "to describe, explain, and predict a phenomenon"), which was not necessarily technology-driven. They mainly dealt with real-time and real-world biological, psychological, and cultural realities. These people understood that most of the arrogant predictions made by Artificial Intelligence researchers in the 60's and 70's hadn't been realized because of fundamental theoretical problems, not because of the lack of powerful enough machines. They observed that even the simplest everyday aspects of human thought, such as common sense, sense of humor, spontaneous metaphorical thought, use of counterfactuals in natural language, to mention only a few, were in fact intractable for the most sophisticated machines. They also observed that the nature of the brain and other bodily mechanisms that make thinking and the mind possible, were by several orders of magnitude, way more complex than what it was thought during the hey-days of Artificial Intelligence. Thus for of course-not people the question whether computers think became uninteresting, since it didn't provide insights into a genuine understanding of the intricacies of human thinking. Today the question is dead. The answer had become a matter of faith.

RAFAEL E. NÚÑEZ, currently at the Department of Psychology of the University of Freiburg, is a research associate of the University of California, Berkeley. He has worked for more than a decade on the foundations of embodied cognition, with special research into the nature and origin of mathematical concepts. He has published in several languages in a variety of areas, and has taught in leading academic institutions in Europe, the United States, and South America. He is the author (with George Lakoff) of Where Mathematics Comes From: How the Embodied Mind Brings Mathematics into Being; and co-editor (with Walter Freeman) of Reclaiming Cognition: The Primacy of Action, Intention, and Emotion.

Speculation about the possibility of a "plurality of worlds" goes back at least as far as Epicurus in the fourth century BC. Admittedly, Epicurus' definition of a "world" was closer to what we would currently regard as a solar system — but he imagined innumerable such spheres, each containing a system of planets, packed together. "There are," he declared, "infinite worlds both like and unlike this world [i.e., solar system] of ours."

The same question was subsequently considered by astronomers and philosophers over the course of many centuries; within the past half century, the idea of the existence of other planets has become a science fiction staple, and people have started looking for evidence of extraterrestrial civilizations. Like Epicurus, many people have concluded that there must be other solar systems out there, consisting of planets orbiting other stars. But they didn't know for sure. Today, we do.

The first "extrasolar" planet (ie, beyond the solar system) was found in 1995 by two Swiss astronomers, and since then another 48 planets have been found orbiting dozens of nearby sun-like stars. This figure is subject to change, because planets are now being found at an average rate of more than one per month; more planets are now known to exist outside the solar system than within it. Furthermore, one star is known to have at least two planets, and another has at least three. We can, in other words, now draw maps of alien solar systems — maps that were previously restricted to the realm of science fiction.

The discovery that there are other planets out there has not, however, caused as much of a fuss as might have been expected, for two reasons. First, decades of Star Trek and its ilk meant that the existence of other worlds was assumed; the discovery has merely confirmed what has lately become a widely-held belief. And second, none of these new planets has actually been seen. Instead, their existence has been inferred through the tiny wobbles that they cause in the motion of their parent stars. The first picture of an extrasolar planet is, however, probably just a few years away. Like the first picture of Earth from space, it is likely to become an iconic image that once again redefines the way we as humans think about our place in the universe.

Incidentally, none of these new planets has a name yet, because the International Astronomical Union, the body which handles astronomical naming, has yet to rule on the matter. But the two astronomers who found the first extrasolar planet have proposed a name for it anyway, and one that seems highly appropriate: they think it should be called Epicurus.

TOM STANDAGE is technology correspondent at The Economist in London and author of the books The Victorian Internet and The Neptune File, both of which draw parallels between episodes in the history of science and modern events. He has also written for the Daily Telegraph, The Guardian, Prospect, and Wired.He is married and lives in Greenwich, England, just down the hill from the Old Royal Observatory.

Another question that has fallen into the dustbin of history is this: Is human nature innately good or evil? This became a gripping topic in the late 17th century, as Enlightment thinkers began to challenge the Christian assumption that man was born a fallen creature. It was a great debate while it lasted: original sin vs. tabla rasa and the perfectability of man; Edmund Burke vs. Tom Paine; Dostoyevsky vs. the Russian reformers. But Darwin and Freud undermined the foundations of both sides, by discrediting the very possibility of discussing human nature in moral or teleological terms. Now the debate has been recast as "nature vs. nurture" and in secular scientific circles at least, man is the higher primate -- a beast with distinctly mixed potential.   

ANN CRITTENDEN is an award-winning journalist and author. She was a reporter for The New York Times from 1975 to 1983, where her work on a broad range of economic issues was nominated for the Pulitzer Prize. She is the author of several books inncluding The Price of Motherhood: Why the Most Important Job in the World is Still the Least Valued. Her articles have appeared in numerous magazines, including The Nation, Foreign Affairs, McCall's, Lear's, and Working Woman.

Metaphysical questions. 

Metaphysical answers haven't disappeared: the new agers are full of them, and so are the old religionists. 

Cosmological questions haven't disappeared: but scientists press them as real questions about the very physical universe. 

But the old Platonic questions about the nature of the good and the form of beauty — they went away when we weren't looking. They won't be back.

JAMES J. O'DONNELL, Professor of Classical Studies and Vice Provost for Information Systems and Computing at the University of Pennsylvania, is the author of Avatars of the Word: From Papyrus to Cyberspace.

At a particular point (yet to be clearly defined) in human cultural evolution, a specific idea took hold that there were two, partially separable, elements present in a living creature: the material body and the force that animated it. On the death of the body the animating force would, naturally, desire the continuation of this-worldly action and struggle to reassert itself (just as one might strive to retrieve a flint axe one had accidentally dropped). If the soul (or spirit) succeeded, it would also seek to repossess its property, including its spouse, and reassert its material appetites. 

The desire of the disembodied soul was viewed as dangerous by the living, who had by all means to enchant, cajole, fight off, sedate, or otherwise distract and disable it. This requirement to keep the soul from the body after death did not last forever, only so long as the flesh lay on the bones. For the progress of the body's decomposition was seen as analogous to the slow progress the soul made toward the threshold of the Otherworld. When the bones where white (or were sent up in smoke or whatever the rite in that community was), then it was deemed that the person had finally left this life and was no longer a danger to the living. Thus it was, that for most of recent human history (roughly the last 35,000 years) funerary rites were twofold: the primary rites zoned off the freshly dead and instantiated the delicate ritual powers designed to keep the unquiet soul at bay; the secondary rites, occurring after weeks or months (or, sometimes — in the case of people who had wielded tremendous worldly power — years), firmly and finally incorporated the deceased into the realm of the ancestors.

Since the rise of science and scepticism, the idea of the danger of the disembodied soul has, for an increasing number of communities, simply evaporated. But there is a law of conservation of questions. "How can I stop the soul of the deceased reanimating the body?" is now being replaced with "How can I live so long that my life becomes indefinite?," a question previously only asked by the most arrogant pharaohs and emperors.

TIMOTHY TAYLOR lecturers in the Department of Archaeological Sciences, University of Bradford, UK. He is the author of The Prehistory of Sex.

The detection of "questions that are no longer asked" is difficult. Old questions, like MacArthur's old soldiers, just fade away. Scientists and scholars in hot pursuit of new questions neither note nor mourn their passing. I regularly face a modest form of the disappearing question challenge when a textbook used in one of my classes is revised. Deletions are hard to find; they leave no voids and are more stealthy than black holes, not even affecting their surrounds. New text content stands out, while missing material must be established through careful line-by-line reading. Whether in textbooks or in life, we don't think much about what is no longer relevant.

My response to the inquiry about questions that are no longer asked is to reframe it and suggest instead a common class of missing questions, those associated with obsolete and inappropriate metaphors. Metaphor is a powerful cognitive tool, which, like all models, clarifies thinking when appropriate, but constrains it when inappropriate. Science is full of them. My professional specialties of neuroscience and biopsychology has mind/brain metaphors ranging from Locke's ancient blank slate (tabula rasa), to the more technologically advanced switchboard, and the metaphor de jour, the computer. None do justice to the brain as a soggy lump of wetware, but linger as cognitive/linguistic models. Natural selection in the realm of metaphors is slow and imperfect. Witness the reference to DNA as a "blueprint" for an organism, when Dawkins' "recipe" metaphor more accurately reflects DNA's incoding of instructions for organismic assembly.

ROBERT R. PROVINE is Professor of Psychology and Neuroscience at the University of Maryland, Baltimore County, and author of Laughter: A Scientific Investigation.

Questions...

We ask many questions ...

...about our species, our gender, our friends, lovers and ourselves, the mystery who each of us is and where in the ant hill the intelligence lies, if each ant has no clue.

We search for the variations amongst a set, try to define the set in its limits and borders against other sets, look for analogies, anomalies and statistical outliers....

There is in fact an almost universal algorithm, like cats stalking their prey, to makes sense of our nature by boundary conditions, alas compiled with spotty statistics and messy heuristics, gullible souls, political machinations, cheats, lies and video tape, in short: human nature. We search and probe, the literate digerati confer virtually, each wondering about the other, each looking at their unique sets of parents, and the impossibility to imagine them in the act of procreation.

In other words, we still have no idea what-so-ever who we really are, what mankind as a whole is all about. We have mild inclinations on where we have been, sort of, and contradictory intentions on where we may be headed, kind of, but all in all, we are remarkably clue-free.

But that question at least need no longer be asked and has indeed vanished after this:

Even when they had way too much to drink, pigs don´t turn into men.

KAI KRAUSE is currently building a research lab dubbed "Byteburg" in a thousand year old castle above the Rhein river in the geometric center of Europe. He asked not to be summed up by previous accomplishments, titles or awards.

A hundred years ago, one of the most fundamental questions in physical science was: How fast is the Earth moving? Many experiments had been performed to measure the speed of the Earth through space as it orbits the sun, and as the solar system orbits the galaxy. The most famous was conducted in 1887 by Albert Michelson and Edward Morley using an optical interferometer. The result they obtained was... zero. Today, scientists regard the question of the Earth's speed through space as meaningless and misconceived, although many non-scientists still refer to the concept.

Why has the question disappeared? Einstein's theory of relativity, published in 1905, denied any absolute frame of rest in the universe; speed is meaningful only relative to other bodies or physical systems. Ironically, some decades later, it was discovered there is a special frame of reference in the universe defined by the cosmic microwave background radiation, the fading afterglow of the big bang. The Earth sweeps through this radiation at roughly 600 km per second (over a million miles per hour) in the direction of the constellation Leo. This is the closest that modern astronomy gets to the notion of an absolute cosmic velocity.

PAUL DAVIES is an internationally acclaimed physicist, writer and broadcaster, now based in South Australia. Professor Davies is the author of some twenty books, including Other Worlds, God and the New Physics, The Edge of Infinity, The Mind of God, The Cosmic Blueprint, Are We Alone? and About Time. He is the recipient of a Glaxo Science Writers' Fellowship, an Advance Australia Award and a Eureka prize for his contributions to Australian science, and in 1995 he won the prestigious Templeton Prize for his work on the deeper meaning of science.

People in the Western world assume women have it all: education, job opportunities, birth control, love control, and financial freedom. But women still lack the essential freedom — equality — they lacked a century ago. Women are minorities in every sector of our government and economy, and women are still expected to raise families while at the same time earning incomes that are comparably lower than what males earn. And in our culture, women are still depicted as whores, bimbos, or bloodsuckers by advertisers to sell everything from computers to cars.

Will it take another century or another millenium before the biological differences between men and women are taken as a carte blanche justification for the unequal treatment of women?

SYLVIA PAULL is Founder, Gracenet (www.gracenet.net) Serving women in high-tech and business media.

I am taking the liberty of sending two questions. (After all, the people on the list like to push the boundaries.)

"Have We Seen the End of Science?"

John Horgan announced the end of science in his book of the same title. Almost weekly the most spectacular advances are being announced and intriguing questions being asked in fields such as biology and physics. The answer was always a resounding no; now nobody asks the question.

"Will the Internet Stock Bubble Burst?"

We certainly know the answer to that one now.

On February 22, 2000 I gave a talk at the Century Association in NYC titled "Modern Finance and Computers". One of the topics that i covered was "will the internet stock bubble burst?" I said it was a classic bubble and would end in the usual way. I cited the example of an Fall, 1999 IPO for VA Linux. This was a company that had a market capitalization of 10 billion dollars at the end of the first day even though it had never shown a profit and was up against competitors such as Dell and IBM.

The NASDAQ reached its high on March 10, 2000, and the internet sector collapsed a couple of weeks later. The high for VA Linux in 2000 was $247;yesterday it closed below $10.

JOSEPH F. TRAUB is the Edwin Howard Armstrong Professor of Computer Science at Columbia University and External Professor at the Santa Fe Institute. He was founding Chairman of the Computer Science Department at Columbia University from 1979 to 1989, and founding chair of the Computer Science and Telecommunications Board of the National Academy of Sciences from 1986 to 1992. From 1971 to 1979 he was Head of the Computer Science Department at Carnegie-Mellon University. Traub is the founding editor of the Journal of Complexity and an associate editor of Complexity. A Festschrift in celebration of his sixtieth birthday was recently published. He is the author of nine books including the recently published Complexity and Information.

Questions disappear when they seem to be answered or unanswerable. The interesting missing questions are the apparently answered ones that are not, and the apparently unanswerable ones that are.

One of life's most profound questions has been thought to be unanswerable. That question is, "Why is life so full of suffering?" Impatience with centuries of theological and philosophical speculation has led many to give up on the big question, and to ask instead only how brain mechanisms work, and why people differ in their experiences of suffering. But the larger question has an answer, an evolutionary answer. The capacities for suffering — pain, hunger, cough, anxiety, sadness, boredom and all the res — have been shaped by natural selection. They seem to be problems because they are so painful and because they are aroused only in adverse circumstances, but they are, in fact, solutions.

The illusion that they are problems is further fostered by the smoke-detector principle — selection has shaped control mechanisms that express defensive responses whenever the costs are less than the protection they provide. This is often indeed, much more often than is absolutely necessary. Thus, while the capacities for suffering are useful and generally well-regulated, most individual instances are excessive or entirely unnecessary. It has not escaped notice that this principle has profound implications for the power and limits of pharmacology to relieve human suffering.

RANDOLPH M. NESSE is Professor of Psychiatry and Director of the Evolution and Human Adaptation Program at the University of Michigan. He is the author, with George Williams, of Why We Get Sick: The New Science of Darwinian Medicine.

Why:

1. If Barbour's theory of Platonia is even roughly correct, then everything exists in a timless universe, and therefore doesn't actually "disappear". Therefore, all questions are always asked, as everything is actually happening at once. I know that doesn't help much, and it dodges the main thrust of the question, but it's one support for my answer, if oblique.

2. Other than forgotten questions that disappear of their own accord, or are in some dead language, or are too personal/particular/atomised (i.e., What did you think of the latest excretion from Hollywood? Is it snowing now? Why is that weirdo across the library reading room looking at me?!?! When will I lose these 35 "friends" who are perched on my belt buckle? etc.) questions don't really disappear. They are asked again and again and are answered again and again, and this is a very good thing. Three Year Olds will always ask "Daddy, where do the stars come fwum?" And daddys will always answer as best they can. Eventually, some little three year old will grow into an adult astronomer and might find even better answers than their daddy supplied them on a cold Christmas night. And they will answer the same simple question with a long involved answer, or possibly, a better and simpler answer. In this way, questions come up again and again, but over time they spin out in new directions with new answers.

3. It's important to not let questions disappear. By doubting the obvious, examining the the same ground with fresh ideas, and questioning recieved ideas, great strides in the collected knowledge of this human project can be (and historically, have been) gained. When we consign a question to the scrap heap of history we run many risks — risks of blind arrogance, deaf self righteousness, and finally choking on the bland pablum of unquestioned dogma.

4. It's important to question the questions. It keeps the question alive, as it refines the question. Question the questions, and then reverse the process - question the questioning of questions. Permit the mind everything, even if it seems repetitive. If you spin your wheels long enough you'll blow a bearing or snap a spring, and the question is re-invented, re-asked, and re-known, but in a way not previously understood. In this way, questions don't disappear, they evolve into other questions. For a while they might bloat up in the sun and smell really weird, but it's all part of the process...

HENRY WARWICK sometimes works as a scientist in the computer industry. He always works as an artist, composer, and writer. He lives in San Francisco, California.

The reason this question is dead is because traditional Skinnerianism, which viewed rats and pigeons as furry and feathered black boxes, guided by simple principles of reinforcement and punishment, is theoretically caput. It can no longer account for the extraordinary things that animals do, spontaneously.

Thus, we now know that animals form cognitive maps of their environment, compute numerosities, represent the relationships among individuals in their social group, and most recently, have some understanding of what others know.

The questions for the future, then, are not "Do animals think?", but "What precisely do they think about, and to what extent do their thoughts differ from our own?"

MARC D. HAUSER is an evolutionary psychologist, and a professor at Harvard University where he is a fellow of the Mind, Brain, and Behavior Program. He is a professor in the departments of Anthropology and Psychology, as well as the Program in Neurosciences. He is the author of The Evolution of Communication, and Wild Minds: What AnimalsThink.

Like mathematics whose symbols can represent physical properties when applied to some scientific problem, God is a convenient symbol for nature, for the way the world works. Einstein's reaction of utter incredibility to the quantum theory from its development in the late 20's until his death in 1955, was echoed by colleagues who had participated in the early creation of the quantum revolution, which Richard Feynman had termed the most radical theory ever.

Well does she?

The simplest example of what sure looks like God playing dice happens when you walk past a store window on a sunny day. Of course you are not just admiring your posture and checking your attire, you are probably watching the guy undressing the manikin, but that is another story.

So how do you see yourself, albeit dimly, while the manikin abuser sees you very clearly? Everyone knows that light is a stream of photons, here from the sun, some striking your nose, then reflected in all directions. We focus on two photons heading for the window. We'll need thousands to get a good picture but two will do for a start. One penetrates the window and impacts the eye of the manikin dresser. The second is reflected from the store window and hits your eye, a fine picture of a good looking pedestrian! What determines what the photons will do? The photons are identical...trust me. Philosophers of science assure us that identical experiments give identical results.

Not so!

The only rational conclusion would seem to be that she plays dice at each impact of the photon. Using a die with 10 faces, good enough for managing this bit of the world, numbers one to nine determine that the photon goes through, a ten and the photon is reflected. Its random...a matter of probability.

Dress this concept up in shiny mathematics and we have quantum science which underlies physics, most of chemistry and molecular biology. It now accounts for 43.7% of our GNP. (this is consistent with 87.1% of all numbers being made up.)

So what was wrong with Einstein and his friends? Probabilistic nature which is applicable to the world of atoms and smaller, has implications which are bizarre, spooky, wierd. Granting that it works, Einstein could not accept it and hoped for a deeper explanation. Today, many really smart physicists are are seeking a kinder, gentler formulation but 99.3% of working physicists go along with the notion that she is one hell-of-a crap shooter.

LEON M. LEDERMAN , the director emeritus of Fermi National Accelerator Laboratory, has received the Wolf Prize in Physics (1982), and the Nobel Prize in Physics (1988). In 1993 he was awarded the Enrico Fermi Prize by President Clinton. He is the author of several books, including (with David Schramm) From Quarks to the Cosmos : Tools of Discovery, and (with Dick Teresi) The God Particle: If the Universe Is the Answer, What Is the Question?

The question disappeared in most of Europe and North America, of course, because of the great movement toward women's employment and career advancement even after marrying and bearing children. Feminist historians have long documented how the "story" of the female heroine used to end with marriage; indeed, this story was so set in stone as late as the 1950's and early 60's in this country that Sylvia Plath's heroine in The Bell Jar had to flirt with suicide in order to try to find a way out of it. Betty Friedan noted in The Feminine Mystique that women (meaning middle class white women; the narrative was always different for women of color and working class women) couldn't "think their way past" marriage and family in terms of imagining a future that had greater dimension. But the narrative shifted and it's safe to say that the female sense of identity in the West, for the first time ever, no longer hinges on the identity of her mate — which is a truly new story in terms of our larger history.

NAOMI WOLF, author, feminist, and social critic, is s an outspoken and influential voice for women's rights and empowerment. she is the author of The Beauty Myth, Fire with Fire, and Promiscuities.

During the early 1980s, I had the wonderful fortune to spend a great deal of time with Richard Feynman, and our innumerable conversations extended over a very broad range of topics (not always physics!). At that time, I had just finished re-reading his wonderful book, The Character of Physical Law, and wanted to discuss an interesting question with him, not directly addressed by his book:

Why is our sense of beauty and elegance such a useful tool for discriminating between a good theory and a bad theory?

And a related question:

Why are the fundamental laws of the universe self-similar?

Over lunch, I put the questions to him.

"It's goddam useless to discuss these things. It's a waste of time," was Dick's initial response. Dick always had an immediate gut-wrenching approach to philosophical questions. Nevertheless, I persisted, because it certainly was to be admitted that he had a strong intuitive sense of the elegance of fundamental theories, and might be able to provide some insight rather than just philosophizing. It was also true that this notion was a successful guiding principle for many great physicists of the twentieth century including Einstein, Bohr, Dirac, Gell-Mann, etc. Why this was so, was interesting to me.

We spent several hours trying to get at the heart of the problem and, indeed, trying to determine if it was even a true notion rather than some romantic representation of science.

We did agree that it was impossible to explain honestly the beauties of the laws of nature in a way that people can feel, without their having some deep understanding of mathematics. It wasn't that mathematics was just another language for physicists, it was a tool for reasoning by which you could connect one statement with another. The physicist has meaning to all his phrases. He needs to have a connection of words to the real world.

Certainly, a beautiful theory meant being able to describe it very simply in terms of fundamental mathematical quantities. "Simply" meant compression into a small mathematical expression with tremendous explanatory powers, which required only a finite amount of interpretation. In other words, a huge number of relationships between data are concisely fit into a single statement. Later, Murray Gell-Mann expressed this point well, when he wrote, "The complexity of what you have to learn in order to be able to read the statement of the law is not really very great compared to the apparent complexity of the data that are being summarized by that law. That apparent complexity is partly removed when the law is formed."

Another driving principle was that the laws of the universe are self similar, in that there are connections between two sets of phenomena previously thought to be distinct. There seemed to be a beauty in the inter-relationships fed by perhaps a prejudice that at the bottom of it all was a simple unifying law.

It was easy to find numerous examples from the history of modern science that fit within this framework (Maxwell's equations for electromagnetism, Einstein's general-relativistic equations for gravitation, Dirac's relativistic quantum mechanics, etc.,), but Dick and I were still working away at the fringes of the problem. So far, all we could do was describe the problem, find numerous examples, but we could not answer what provided the feeling for great intuitive guesses.

Perhaps, our love of symmetries and patterns, are an integral part of why would embrace certain theories and not others. For example, for every conservation law, there was a corresponding symmetry, albeit sometimes these symmetries would be broken. But this led us to another question: Is symmetry inherent in nature or is it something we create? When we spoke of symmetries, we were referring to the symmetry of the mathematical laws of physics, not to the symmetry of objects commonly found in nature. We felt that symmetry was inherent in nature, because it was not something that we expected to find in physics. Another psychological prejudice was our love for patterns. The simplicity of the patterns in physics were beautiful. This does not mean simple in action ­ the motion of the planets and of atoms can be very complex, but the basic patterns underneath are simple. This is what is common to all of our fundamental laws.

It should be noted that we could also come up with numerous examples where one's sense of elegance and beauty led to beautiful theories that were wrong. A perfect example of a mathematically elegant theory that turned out to be wrong is Francis Crick's 1957 attempt at working out the genetic coding problem (Codes without Commas). It was also true that there were many examples of physical theories that were pursued on the basis of lovely symmetries and patterns, and that these also turned out to be false. Usually, these were false because of some logical inconsistency or the crude fact that they did not agree with experiment.

The best that Dick and I could come up with was an unscientific response, which is, given our fondness for patterns and symmetry, we have a prejudice — that nature is simple and therefore beautiful.

Since that time, the question has disappeared from my mind, and it is fun thinking about it again, but in doing scientific research, I now have to concern myself with more pragmatic questions.

AL SECKEL is acknowledged as one of the world's leading authorities on illusions. He has given invited lectures on illusions at Caltech, Harvard, MIT, Berkeley, Oxford University, University of Cambridge, UCLA, UCSD, University of Lund, University of Utrecht, and many other fine institutions. Seckel is currently under contract with the Brain and Cognitive Division of the MIT Press to author a comprehensive treatise on illusions, perception, and cognitive science.

Psychology for much of the 20th century was dominated by the view that men and women were psychologically identical. So pervasive was this assumption that research articles in psychology journals prior to the 1970's rarely bothered to report the sex of their study participants. Women and men were understood to be interchangeable. Findings for one sex were presumed to be applicable to the other. Once the American Psychological Association required sex of participants to be reported in published experiments, controversy erupted over whether men and women were psychologically different. The past three decades of empirical research has resolved this issue, at least in delimited domains. Although women and men show great psychological similarity, they also differ in profound ways. They diverge in the sexual desires they express and mating strategies they pursue. They differ in the time they allocate to friends and relentlessness with which they pursue status. They display distinct abilities in reading other's minds, feeling other's feelings, and responding emotionally to specific traumas in their lives. Men opt for a wider range of risky activities, are more prone to violence against others, make sharper in-group versus out-group distinctions, and commit the vast majority of homicides worldwide. The question 'Do men and women differ psychologically?' has been replaced with more interesting questions. In what ways do these sex differences create conflict between men and women? Have the selection pressures that created these differences vanished in the modern world? How can societies premised on equality grapple with the profound psychological divergences of the sexes?

DAVID M. BUSS is Professor of Psychology at the University of Texas, Austin, and author of several books, most recently The Dangerous Passion:  Why Jealousy is as Necessary as Love and Evolutionary Psychology:  The New Science of the Mind , and The Evolution of Desire:  Strategies of Human Mating. 

The greatest idea that's disappeared from mainstream science this past 400 years is surely that of God. The greats who laid the foundations of modern science in the 17th century (Galileo, Newton, Leibnitz, Descartes) and the significant-but-not-quite-so-greats (Robert Boyle, John Ray, etc.) were theologians as much as they were scientists and philosophers. They wanted to know how things are, of course — but also what God had in mind when he made them this way. They took it for granted, or contrived to prove to their own satisfaction, that unless there is a God, omniscient and mindful, then there could be no Universe at all.

Although David Hume did much to erode such argument, it persisted well into the 19th century. Recently I have been intrigued to find James Hutton — who, as one of the founders of modern geology, is one of the boldest and most imaginative of all scientists — earnestly wondering in a late 18th century essay what God could possibly have intended when he made volcanoes. The notion that there could be no complex and adapted beings at all without a God to create them, was effectively the default position in orthodox biology until (as Dan Dennett has so succinctly explained) Charles Darwin showed how natural selection could produce complexity out of simplicity, and adaptation out of mere juxtaposition. Today, very obviously, no Hutton-style musing would find its way into a refereed journal. In Nature, God features only as the subject of (generally rather feeble) sociological and sometimes evolutionary speculation.

Religion obviously flourishes still, but are religion and science now condemned to mortal conflict? Fundamentalist-atheists would have it so, but I think not. The greatest ideas in philosophy and science never really go away, even if they do change their form or go out of fashion, but they do take a very long time to unfold. For at least 300 years — from the 16th to the 19th centuries — emergent science and post- medieval theology were deliberately intertwined, in many ingenious ways. Through the past 150, they have been just as assiduously disentangled. But the game is far from over. Cosmologists and metaphysicians continue to eye and circle each other. Epistemology — how we know what's true — is of equal interest to scientists and theologians, and each would be foolish to suppose that the other has nothing to offer. How distant is the religious notion of revelation from Dirac's — or Keats's? — perception of truth as beauty? Most intriguingly of all, serious theologians are now discussing the role of religion in shaping emotional response while modern aficionados of artificial intelligence acknowledge (as Hume did) that emotion is an essential component of thought itself. Lastly, the ethics of science and technology — how we should use our new-found power — are the key discussions of our age and it is destructive to write religion out of the act, even if the priests, rabbis and mullahs who so far have been invited to take part have often proved disappointing.

I don't share the modern enthusiasm for over-extended life but I would like to see how the dialogue unfolds in the centuries to come.

COLIN TUDGE is a Research Fellow at the Centre for Philosophy, London School of Economics. His two latest books are The Variety of Life and In Mendel's Footnotes.

This question is no longer asked, not because the question has been answered (although I happen to believe the answer is e to the i pi) but because the search for knowledge about the spiritual world has shifted focus as a result of science and maths cornering all the physical and numerical answers. Along with "Did Adam have a navel?" and "Did Jesus' mother give birth parthenogenetically?", this question is no longer asked by anyone of reasonable intelligence. Those who would in the past have searched for scientific support for their spiritual ideas have finally been persuaded that this is a demeaning use for human brainpower and that by moving questions about the reality of spiritual and religious ideas into the same category as questions about mind (as opposed to brain) they will retain the respect of unbelievers and actually get nearer to an understanding of the sources of their preoccupations.

As an addendum, although I wasn't asked I would like also to answer the question "What questions should disappear and why?"

The one question that should disappear as soon as possible ­ and to a certain extent scientists are to blame for the fact that it is still asked ­ is: What is the explanation for astrology/UFOs/clairvoyance/telepathy/any other 'paranormal' phenomenon you care to name?

This question is still asked because scientists and science educators have failed to get over to the public the fact that there is only one method of explaining phenomena ­ the scientific method. Therefore, anything that people are puzzled by that has not been explained either doesn't exist or there isn't yet enough evidence to prove that it does. But still I get the impression that for believers in these phenomena there are two types of explanatory system ­ science and nonscience (you can pronounce the latter 'nonsense' if you like). When you try to argue with these people by pointing out that there isn't sufficient repeatable evidence even to begin to attempt an explanation in scientific terms, they just say that this particular phenomenon doesn't require that degree of stringency. When the evidence is strong enough to puzzle scientists as well as nonscientists, they'll begin to devise explanations ­ scientific explanations.

There's a good example of how this works currently with the interest taken in St John's wort as a possible treatment for depression. Once there was enough consistent evidence to suggest that there might be an effect, clinical trials were planned and are now under way. Interestingly, an indication that there might be a genuine effect comes from a substantial body of information suggesting that there are adverse drug interactions between St John's wort and immunosuppressive drugs taken by transplant patients. Once an 'alternative' remedy actually causes harm as well as having alleged benefits, it's claimed effects are more likely to be genuine. One argument against most of the quack remedies around, such as homoeopathy, is that they are entirely safe (although this is seen as a recommendation, by the gullible.)

The demand that phenomena that are not explainable in scientific terms should be accepted on the basis of some other explanation similar to the argument you might care to use with your bank manager that there is more than one type of arithmetic. Using his conventional accounting methods he might think your account is overdrawn but you would argue that, although the evidence isn't as strong as his method might require, you believe you still have lots of money in your account and therefore will continue writing cheques. (As like as not, this belief in a positive balance in your account will be based on some erroneous assumption ­ for example, that you still have a lot of blank cheques left in your chequebook.)

KARL SABBAGH is a television producer who has turned to writing. Among his television programs are "Skyscraper" ­ a four-hour series about the design and construction of a New York skyscraper; "Race for the Top" ­ a documentary about the hunt for top quark; and "21st Century Jet" ­ a five part series following Boeing's new 777 airliner from computer design to entry into passenger service.He is the author of six books including Skyscraper, 21st Century Jet, and A Rum Affair .

My colleagues in the fashionable fields of string theory and quantum gravity advertise themselves as searching desperately for the 'Theory of Everything", while their experimental colleagues are gravid with the "God Particle", the marvelous Higgson which is the somewhat misattributed source of all mass. (They are also after an understanding of the earliest few microseconds of the Big Bang.) As Bill Clinton might remark, it depends on what the meaning of "everything" is. To these savants, "everything" means a list of some two dozen numbers which are the parameters of the Standard Model. This is a set of equations which already exists and does describe very well what you and I would be willing to settle for as "everything". This is why, following Bob Laughlin, I make the distinction between "everything" and "every thing". Every thing that you and I have encountered in our real lives, or are likely to interact with in the future, is no longer outside of the realm of a physics which is transparent to us: relativity, special and general; electromagnetism; the quantum theory of ordinary, usually condensed, matter; and, for a few remote phenomena, hopefully rare here on earth, our almost equally cut-and-dried understanding of nuclear physics. [Two parenthetic remarks: 1) I don't mention statistical mechanics only because it is a powerful technique, not a body of facts; 2) our colleagues have done only a sloppy job so far of deriving nuclear physics from the Standard Model, but no one really doubts that they can.]

I am not arguing that the search for the meaning of those two dozen parameters isn't exciting, interesting, and worthwhile: yes, it's not boring to wonder why the electron is so much lighter than the proton, or why the proton is stable at least for another 35 powers of ten years, or whether quintessence exists. But learning why can have no real effect on our lives, spiritually inspiring as it would indeed be, even to a hardened old atheist like myself.

When I was learning physics, half a century ago, the motivation for much of what was being done was still "is quantum theory really right?" Not just QED, though the solution of that was important, but there were still great mysteries in the behavior of ordinary matter--like superconductivity, for instance. It was only some twenty years later that I woke up to the fact that the battle had been won, probably long before, and that my motivation was no longer to test the underlying equations and ideas, but to understand what is going on. Within the same few years , the molecular biology pioneers convinced us we needed no mysterious "life force" to bring all of life under the same umbrella. Revolutions in geology, in astrophysics, and the remarkable success of the Standard Model in sorting out the fundamental forces and fields, leave us in the enviable position I described above: given any problematic phenomenon, we know where to start, at least. And nothing uncovered in string theory or quantum gravity will make any difference to that starting point.

Is this Horgan's End of Science? Absolutely not. It's just that the most exciting frontier of science no longer lies at the somewhat sophomoric — or quasi-religious — level of the most "fundamental" questions of "what are we made of?" and the like; what needs to be asked is "how did all this delightful complexity arise from the stark simplicity of the fundamental theory?" We have the theory of every thing in any field of science you care to name, and that's about as far as it gets us. If you like, science is now almost universally at the "software" level; the fundamental physicists have given us all the hardware we need, but that doesn't solve the problem, in physics as in every other field. It's a different game, probably a much harder one in fact, as it has often been in the past; but the game is only begun. 

PHILIP W. ANDERSON is a Nobel laureate physicist at Princeton and one of the leading theorists on superconductivity. He is the author of A Career in Theoretical Physics, and Economy as a Complex Evolving System.

It has become unfashionable to ask about the structure of reality without already having chosen a framework in which to ponder the answer, be it scientific, religious or sceptical. A sense of wonder at the sheer appearance of the world, moment by moment, has been lost.

To look at the world in wonder, and to stay with that sense of wonder without jumping straight past it, has become almost impossible for someone taking science seriously. The three dominant reactions are: to see science as the only way to get at the truth, at what is really real; to accept science but to postulate a more encompassing reality around or next to it, based on an existing religion; or to accept science as one useful approach in a plurality of many approaches, neither of which has anything to say about reality in any ultimate way.

The first reaction leads to a sense of wonder scaled down to the question of wonder about the underlying mathematical equations of physics, their interpretation, and the complexity of the phenomena found on the level of chemistry and biology. The second reaction tends to allow wonder to occur only within the particular religous framework that is accepted on faith. The third reaction allows no room for wonder about reality, since there is no ultimate reality to wonder about.

Having lost our ability to ask what reality is like means having lost our innocence. The challenge is to regain a new form of innocence, by accepting all that we can learn from science, while simultaneously daring to ask 'what else is true?' In each period of history, the greatest philosophers struggled with the question of how to confront skepticism and cynicism, from Socrates and Descartes to Kant and Husserl in Europe, and Nagarjuna and many others in Asia and elsewhere. I hope that the question "What is Reality?" will reappear soon, as a viable intellectual question and at the same time as an invitation to try to put all our beliefs and frameworks on hold. Looking at reality without any filter may or may not be possible, but without at least trying to do so we will have given up too soon.

PIET HUT is professor of astrophysics at the Institute for Advanced Study, in Princeton. He is involved in the project of building GRAPEs, the world's fastest special-purpose computers, at Tokyo University, and he is also a founding member of the Kira Institute.

Or at least, certainly not the ones that have so far been submitted to this list, since the questions posted are proof positive that they have not disappeared at all, or at least, not altogether. Sure, some questions have their heyday for a while, and then they may disappear for many a moon. But the great question you posed -- what questions have disappeared? -- shows that they were just waiting for a question like this for someone to be reminded just how much emptier our existence would be without certain questions.

But I also think that some questions certainly have gone by the wayside for a long time, though not necessarily the ones that so far have been posed. We may ask, for instance, questions like, Has history ended?, and then go on to offer up a response of one sort or another. But when is the last time we asked, what *is* history? What different types of history are there? What makes history history, regardless of which type it is?

Or we may ask: Why have certain questions been discarded? But when's the last time anyone has asked, What is a question? What does a question do? What does a question to do us, and what do we do to it?

We may ask: How do people differ in how they think and learn? But do we still ask: What is thinking? What is learning?

Instead, we seem to take for granted that we know what history is, that we know what thinking is, that we know what learning is, when in fact if we delved a little more into these questions, we may well find that none of us hold the same views on what these rich concepts mean and how they function. Which leads me to this perspective: What *has* all but disappeared, I think, is a way of answering questions, regardless of which one is being posed, regardless of how seemingly profound or off-beat or mundane it is. I'm speaking of the kind of rigorous, exhaustive, methodical yet highly imaginative scrutiny of a Socrates or a Plato that challenged all assumptions embedded in a question, and that revealed breathtakingly new vistas and hidden likenesses between seemingly disparate entities.

Who these days takes the time and effort, much less has the critical and creative acumen, to answer questions as those I've already posed, much less such questions as ¨What is human good?¨ or ¨What is a good human?¨in the soul-stirringly visionary yet at the same time down-to-earth way they did? We need a new generation of questioners in the mold of Plato and Sorcrates, people who dare to think a bit outside the lines, who take nothing for granted when a question is posed, and who subject their scrutiny to continual examination and consideration of cogent objections and alternative ways of seeing.

CHRISTOPHER PHILLIPS is the author of ¨Socrates Cafe: A Fresh Taste of Philosophy¨, and founder-executive director of the nonprofit Society for Philosophical Inquiry.

This question haunted serious writers in the early 20th century, when critics sought a product that measured up to the European standard. Now it is dead, and the underlying notion is in ICU. What happened?

Well, the idea itself was never a very good one. It had breathtakingly hazy contours. It ignored the work of authors like Melville, Hawthorne, Wharton, and Twain. And it seemed to assume that a single novel could sum up this vast and complex nation. I'd like to think its disappearance reflects these problems. 

But technology also helped shelve the question. As media proliferated, literature grew less central. If the Great American Novel appeared tomorrow, how many people would actually read it? My guess: Most would wait for the movie.

DANIEL McNEILL is the author of The Face, and principal author of the best-selling Fuzzy Logic, which won the Los Angeles Times Book Prize in Science and Technology, and was a New York Times "Notable Book of the Year".

Did Fermat's question, "is it true that there are no integers x, y, z and n, all greater than 2, such that x^n + y^n = z^n?", F? for short, raised in the 17th century, disappear when Andrew Wiles answered it affirmatively by a proof of Fermat's theorem F in 1995?

The answer is no.

The question F? can be explained to every child, but the proof of F is extremely sophisticated requiring techniques and results way beyond the reach of elementary arithmetic, thus raising the quest for conceptually simpler proofs. What is going on here, why do such elementary theorems require such intricate machinery for their proof? The fact of the truth of F itself is hardly of vital interest. But, in the wake of Goedel's incompleteness proof of 1931, F? finds it place in a sequence of elementary number theoretic questions for which there provably cannot exist any algorithmic proof procedure!

Or take the question D? raised by the gut feeling that there are more points on a straight line segment than there are integers in the infinite sequence 1,2,3,4,.... Before it can be answered the question what is meant by "more" must be dealt with. This done by the 18th Century's progress in the Foundations, D? became amenable to Cantor's diagonal argument, establishing theorem D. But this was by no means the end of the question!

The proof gave rise to new fields of investigation and new ideas. In particular, the Continuum hypothesis C?, a direct descendant of D? was shown to be "independent" of the accepted formal system of set theory. A whole new realm of questions sprang up; questions X? that are answered by proofs of independence, bluntly by: "that depends" ‹ on what you are talking about, what system you are using, on your definition of the word "is" and so forth. With this they give rise to comparative studies of systems without as well as with the assumption X added. Euclid's parallel axiom in geometry, is the most popular early example.

What about the question as to the nature of infinitesimal's, a question that has plagued us ever since Leibniz. Euler and his colleagues had used them with remarkable success boldly following their intuition. But in the 18th Century mathematicians became self conscious. By the time we were teaching our calculus classes by means of epsilon's, delta's and Dedekind cuts some of us might have thought that Cauchy, Weierstrass and Dedekind had chased the question away. But then along came logicians like Abraham Robinson with a new take on it with so-called non standard quantities ‹ another favorite of the popular science press.

Finally, turning to a controversial issue; the question of the existence of God can neither be dismissed by a rational "No" nor by a politically expedient "Yes". Actually as a plain yes-or-no question it ought to have disappeared long ago. Nietzsche, in particular, did his very best over a hundred years ago to make it go away. But the concept of God persists and keeps a maze of questions afloat, such as "who means what by Him"?, "do we need a boogie man to keep us in line"?, "do we need a crutch to hold despair at bay"? and so forth, all questions concerning human nature.

Good questions do not disappear, they mature, mutate and spawn new questions.

VERENA HUBER-DYSON, is a mathematician who taught at UC Berkeley in the early sixties, then at the U of Illinois' at Chicago Circle, before retiring from the University of Calgary. Her research papers on the interface between Logic and Algebra concern decision problems in group theory. Her monograph Goedel's theorem: a workbook on formalization is an attempt at a self contained interdisciplinary introduction to logic and the foundations of mathematics.

I am going to take slight liberty with your question. With the publication a decade ago of Francis Fukuyama's justly acclaimed article The End Of History, many pundits and non-pundits assumed that historical forces and trends had been spent. The era of the "isms" was at an end; liberal democracy, market forces, and globalization had triumphed; the heavy weight of the past was attenuating around the globe.

At the start of 2001, we are no longer asking "Has History Ended?" History seems all too alive. The events of Seattle challenged the globalization behemoth; the world is no longer beating a path to internet startups; Communist and fascist revivals have emerged in several countries; the historical legacies in areas like the Balkans and the Middle East are as vivid as ever; and, as I noted in response to last year's question, much of Africa is at war. As if to remind us of our naivete, Fidel Castro and Saddam Hussein have been in "office" as long as most Americans can remember. If George II is ignorant of this history, he is likely to see it repeated.

HOWARD GARDNER, the major proponent of the theory of multiple intelligences, is Professor of Education at Harvard University and author of numerous books including The Mind's New Science and Extraordinary Minds: Portraits of Four Exceptional Individuals.

This question (or pair of questions) was on everyone's lips in the 1970s, following the oil shortage and lines at gas stations. It stimulated a lot of good thinking and good work on alternative energy sources, renewable energy sources, and energy efficiency. Although this question is still asked by many knowledgeable and concerned people, it has disappeared from the public's radar screen (or, better, television screen). Even the recent escalation of fuel prices and the electricity shortage in California have not lent urgency to thinking ahead about energy.

But we should be asking, we should be worrying, and we should be planning. A real energy crisis is closer now than it was when the question had high currency. The energy-crisis question is only part of a larger question: How is humankind going to deal in the long term with its impact on the physical world we inhabit (of which the exhaustion of fossil fuels is only a part)? Another way to phrase the larger question: Are we going to manage more or less gracefully a transition to a sustainable world, or will eventual sustainability be what's left, willy nilly, after the chaos of unplanned, unanticipated change?

Science will provide no miracles (as the Wall Street Journal, in its justification of inaction, would have us believe), but science can do a lot to ameliorate the dislocations that this century will bring. We need to encourage our public figures to lift their eyes beyond the two-, four-, and six-year time horizons of their jobs.

KENNETH FORD is a retired physicist who teaches at Germantown Friends School in Philadelphia. He is the co-author, with John Wheeler, of Geons, Black Holes, and Quantum Foam: A Life in Physics.