"WHAT IS YOUR DANGEROUS IDEA?"

KARL SABBAGH
Writer and Television Producer; Author, The Riemann Hypothesis

The human brain and its products are incapable of understanding the truths about the universe

Our brains may never be well-enough equipped to understand the universe and we are fooling ourselves if we think they will.

Why should we expect to be able eventually to understand how the universe originated, evolved, and operates? While human brains are complex and capable of many amazing things, there is not necessarily any match between the complexity of the universe and the complexity of our brains, any more than a dog's brain is capable of understanding every detail of the world of cats and bones, or the dynamics of stick trajectories when thrown. Dogs get by and so do we, but do we have a right to expect that the harder we puzzle over these things the nearer we will get to the truth? Recently I stood in front of a three metre high model of the Ptolemaic universe in the Museum of the History of Science in Florence and I remembered how well that worked as a representation of the motions of the planets until Copernicus and Kepler came along.

Nowadays, no element of the theory of giant interlocking cogwheels at work is of any use in understanding the motions of the stars and planets (and indeed Ptolemy himself did not argue that the universe really was run by giant cogwheels). Occam's Razor is used to compare two theories and allow us to choose which is more likely to be 'true' but hasn't it become a comfort blanket whenever we are faced with aspects of the universe that seem unutterably complex — string theory for example. But is string theory just the Ptolemaic clockwork de nos jours? Can it be succeeded by some simplification or might the truth be even more complex and far beyond the neural networks of our brain to understand?

The history of science is littered with examples of two types of knowledge advancement. There is imperfect understanding that 'sort of']' works, and is then modified and replaced by something that works better, without destroying the validity of the earlier theory. Newton's theory of gravitation replaced by Einstein. Then there is imperfect understanding that is replaced by some new idea which owes nothing to older ones. Phlogiston theory, the ether, and so on are replaced by ideas which save the phenomena, lead to predictions, and convince us that they are nearer the truth. Which of these categories really covers today's science? Could we be fooling ourselves by playing around with modern phlogiston?

And even if we are on the right lines in some areas, how much of what there is to be understood in the universe do we really understand? Fifty percent? Five percent? The dangerous idea is that perhaps we understand half a percent and all the brain and computer power we can muster may take us up to one or two percent in the lifetime of the human race.

Paradoxically, we may find that the only justification for pursuing scientific knowledge is for the practical applications it leads to — a view that runs contrary to the traditional support of knowledge for knowledge's sake. And why is this paradoxical? Because the most important advances in technology have come out of research that was not seeking to develop those advances but to understand the universe.

So if my dangerous idea is right — that the human brain and its products are actually incapable of understanding the truths about the universe — it will not — and should not — lead to any diminution at all in our attempts to do so. Which means, I suppose, that it's not really dangerous at all.

RUPERT SHELDRAKE
Biologist, London; Author of The Presence of the Past

A sense of direction involving new scientific principles

We don't understand animal navigation.

No one knows how pigeons home, or how swallow migrate, or how green turtles find Ascension Island from thousands of miles away to lay their eggs. These kinds of navigation involve more than following familiar landmarks, or orientating in a particular compass direction; they involve an ability to move towards a goal.

Why is this idea dangerous? Don't we just need a bit more time to explain navigation in terms of standard physics, genes, nerve impulses and brain chemistry? Perhaps.

But there is a dangerous possibility that animal navigation may not be explicable in terms of present-day physics. Over and above the known senses, some species of animals may have a sense of direction that depends on their being attracted towards their goals through direct field-like connections. These spatial attractors are places with which the animals themselves are already familiar, or with which their ancestors were familiar.

What are the facts? We know more about pigeons than any other species. Everyone agrees that within familiar territory, especially within a few miles of their home, pigeons can use landmarks; for example, they can follow roads. But using familiar landmarks near home cannot explain how racing pigeons return across unfamiliar terrain from six hundred miles away, even flying over the sea, as English pigeons do when they are raced from Spain.

Charles Darwin, himself a pigeon fancier, was one of the first to suggest a scientific hypothesis for pigeon homing. He proposed that they might use a kind of dead reckoning, registering all the twists and turns of the outward journey. This idea was tested in the twentieth century by taking pigeons away from their loft in closed vans by devious routes. They still homed normally. So did birds transported on rotating turntables, and so did birds that had been completely anaesthetized during the outward journey.

What about celestial navigation? One problem for hypothetical solar or stellar navigation systems is that many animals still navigate in cloudy weather. Another problem is that celestial navigation depends on a precise time sense. To test the sun navigation theory, homing pigeons were clock-shifted by six or twelve hours and taken many miles from their lofts before being released. On sunny days, they set off in the wrong direction, as if a clock-dependent sun compass had been shifted. But in spite of their initial confusion, the pigeons soon corrected their courses and flew homewards normally.

Two main hypotheses remain: smell and magnetism. Smelling the home position from hundreds of miles away is generally agreed to be implausible. Even the most ardent defenders of the smell hypothesis (the Italian school of Floriano Papi and his colleagues) concede that smell navigation is unlikely to work at distances over 30 miles.

That leaves a magnetic sense. A range of animal species can detect magnetic fields, including termites, bees and migrating birds. But even if pigeons have a compass sense, this cannot by itself explain homing. Imagine that you are taken to an unfamiliar place and given a compass. You will know from the compass where north is, but not where home is.

The obvious way of dealing with this problem is to postulate complex interactions between known sensory modalities, with multiple back-up systems. The complex interaction theory is safe, sounds sophisticated, and is vague enough to be irrefutable. The idea of a sense of direction involving new scientific principles is dangerous, but it may be inevitable.

TOR NØRRETRANDERS
Science Writer; Consultant; Lecturer, Copenhagen; Author, The User Illusion

Social Relativity

Relativity is my dangerous idea. Well, neither the special nor the general theory of relativity, but what could be called social relativity: The idea that the only thing that matters to human well-being is how one stands relatively to others. That is, only the relative wealth of a person is important, the absolute level does not really matter, as soon as everyone is above the level of having their immediate survival needs fulfilled.

There is now strong and consistent evidence (from fields such as microeconomics, experimental economics, psychology, sociolology and primatology) that it doesn't really matter how much you earn, as long as you earn more than your wife's sister's husband. Pioneers in these discussions are the late British social thinker Fred Hirsch and the American economist Robert Frank.

Why is this idea dangerous? It seems to imply that equality will never become possible in human societies: The driving force is always to get ahead of the rest. Nobody will ever settle down and share.

So it would seem that we are forever stuck with poverty, disease and unjust hierarchies. This idea could make the rich and the smart lean back and forget about the rest of the pack.

But it shouldn't.

Inequality may subjectively seem nice to the rich, but objectively it is not in their interest.

A huge body of epidemiological evidence points to the fact that inequality is in fact the prime cause for human disease. Rich people in poor countries are more healthy than poor people in rich countries, even though the latter group has more resources in absolute terms. Societies with strong gradients of wealth show higher death rates and more disease, also amongst the people at the top. Pioneers in these studies are the British epidemiologists Michael Marmot and Richard Wilkinson.

Poverty means spreading of disease, degradation of ecosystems and social violence and crime — which are also bad for the rich. Inequality means stress to everyone.

Social relativity then boils down to an illusion: It seems nice to me to be better off than the rest, but in terms of vitals — survival, good health — it is not.

Believing in social relativity can be dangerous to your health.

ERIC R. KANDEL
Biochemist and University Professor, Columbia University; Recipient, The Nobel Prize, 2000; Author, Cellular Basis of Behavior

Free will is exercised unconsciously, without awareness

It is clear that consciousness is central to understanding human mental processes, and therefore is the holy grail of modern neuroscience. What is less clear is that much of our mental processes are unconscious and that these unconscious processes are as important as conscious mental processes for understanding the mind. Indeed most cognitive processes never reach consciousness.

As Sigmund Freud emphasized at the beginning of the 20th century most of our perceptual and cognitive processes are unconscious, except those that are in the immediate focus of our attention. Based on these insights Freud emphasized that unconscious mental processes guide much of human behavior.

Freud's idea was a natural extension of the notion of unconscious inference proposed in the 1860s by Hermann Helmholtz, the German physicist turned neural scientist. Helmholtz was the first to measure the conduction of electrical signals in nerves. He had expected it to be as the speed of light, fast as the conduction of electricity in copper cables, and found to his surprise that it was much slower, only about 90m sec. He then examined the reaction time, the time it takes a subject to respond to a consciously a perceived stimulus, and found that it was much, much slower than even the combined conduction times required for sensory and motor activities.

This caused Helmholz to argue that a great deal of brain processing occurred unconsciously prior to conscious perception of an object. Helmholtz went on to argue that much of what goes on in the brain is not represented in consciousness and that the perception of objects depends upon "unconscious inferences" made by the brain, based on thinking and reasoning without awareness. This view was not accepted by many brain scientists who believed that consciousness is necessary for making inferences. However, in the 1970s a number of experiments began to accumulate in favor of the idea that most cognitive processes that occur in the brain never enter consciousness.

Perhaps the most influential of these experiments were those carried out by Benjamin Libet in 1986. Libet used as his starting point a discovery made by the German neurologist Hans Kornhuber. Kornhuber asked volunteers to move their right index finger. He then measured this voluntary movement with a strain gauge while at the same time recording the electrical activity of the brain by means of an electrode on the skull. After hundreds of trials, Kornhuber found that, invariably, each movement was preceded by a little blip in the electrical record from the brain, a spark of free will! He called this potential in the brain the "readiness potential" and found that it occurred one second before the voluntary movement.

Libet followed up on Kornhuber's finding with an experiment in which he asked volunteers to lift a finger whenever they felt the urge to do so. He placed an electrode on a volunteer's skull and confirmed a readiness potential about one second before the person lifted his or her finger. He then compared the time it took for the person to will the movement with the time of the readiness potential.

Amazingly, Libet found that the readiness potential appeared not after, but 200 milliseconds before a person felt the urge to move his or her finger! Thus by merely observing the electrical activity of the brain, Libet could predict what a person would do before the person was actually aware of having decided to do it.

These experiments led to the radical insight that by observing another person's brain activity, one can predict what someone is going to do before he is aware that he has made the decision to do it. This finding has caused philosophers of mind to ask: If the choice is determined in the brain unconsciously before we decide to act, where is free will?

Are these choices predetermined? Is our experience of freely willing our actions only an illusion, a rationalization after the fact for what has happened? Freud, Helmholtz and Libet would disagree and argue that the choice is freely made but that it happens without our awareness. According to their view, the unconscious inference of Helmholtz also applies to decision-making.

They would argue that the choice is made freely, but not consciously. Libet for example proposes that the process of initiating a voluntary action occurs in an unconscious part of the brain, but that just before the action is initiated, consciousness is recruited to approve or veto the action. In the 200 milliseconds before a finger is lifted, consciousness determines whether it moves or not.

Whatever the reasons for the delay between decision and awareness, Libet's findings now raise the moral question: Is one to be held responsible for decisions that are made without conscious awareness?

DANIEL GOLEMAN
Psychologist; Author, Emotional Intelligence

Cyber-disinhibition

The Internet inadvertently undermines the quality of human interaction, allowing destructive emotional impulses freer reign under specific circumstances. The reason is a neural fluke that results in cyber-disinhibition of brain systems that keep our more unruly urges in check. The tech problem: a major disconnect between the ways our brains are wired to connect, and the interface offered in online interactions.

Communication via the Internet can mislead the brain's social systems. The key mechanisms are in the prefrontal cortex; these circuits instantaneously monitor ourselves and the other person during a live interaction, and automatically guide our responses so they are appropriate and smooth. A key mechanism for this involves circuits that ordinarily inhibit impulses for actions that would be rude or simply inappropriate — or outright dangerous.

In order for this regulatory mechanism to operate well, we depend on real-time, ongoing feedback from the other person. The Internet has no means to allow such realtime feedback (other than rarely used two-way audio/video streams). That puts our inhibitory circuitry at a loss — there is no signal to monitor from the other person. This results in disinhibition: impulse unleashed.

Such disinhibition seems state-specific, and typically occurs rarely while people are in positive or neutral emotional states. That's why the Internet works admirably for the vast majority of communication. Rather, this disinhibition becomes far more likely when people feel strong, negative emotions. What fails to be inhibited are the impulses those emotions generate.

This phenomenon has been recognized since the earliest days of the Internet (then the Arpanet, used by a small circle of scientists) as "flaming," the tendency to send abrasive, angry or otherwise emotionally "off" cyber-messages. The hallmark of a flame is that the same person would never say the words in the email to the recipient were they face-to-face. His inhibitory circuits would not allow it — and so the interaction would go more smoothly. He might still communicate the same core information face-to-face, but in a more skillful manner. Offline and in life, people who flame repeatedly tend to become friendless, or get fired (unless they already run the company).

The greatest danger from cyber-disinhibition may be to young people. The prefrontal inhibitory circuitry is among the last part of the brain to become fully mature, doing so sometime in the twenties. During adolescence there is a developmental lag, with teenagers having fragile inhibitory capacities, but fully ripe emotional impulsivity.

Strengthening these inhibitory circuits can be seen as the singular task in neural development of the adolescent years.

One way this teenage neural gap manifests online is "cyber-bullying," which has emerged among girls in their early teens. Cliques of girls post or send cruel, harassing messages to a target girl, who typically is both reduced to tears and socially humiliated. The posts and messages are anonymous, though they become widely known among the target's peers. The anonymity and social distance of the Internet allow an escalation of such petty cruelty to levels that are rarely found in person: face-to-face seeing someone cry typically halts bullying among girls — but that inhibitory signal cannot come via Internet.

A more ominous manifestation of cyber-disinhibition can be seen in the susceptibility of teenagers induced to perform sexual acts in front of webcams for an anonymous adult audience who pay to watch and direct. Apparently hundreds of teenagers have been lured into this corner of child pornography, with an equally large audience of pedophiles. The Internet gives strangers access to children in their own homes, who are tempted to do things online they would never consider in person.

Cyber-bullying was reported last week in my local paper. The Webcam teenage sex circuit was a front-page story in The New York Times two days later.

As with any new technology, the Internet is an experiment in progress. It's time we considered what other such downsides of cyber-disinhibition may be emerging — and looked for a technological fix, if possible. The dangerous thought: the Internet may harbor social perils our inhibitory circuitry was not designed to handle in evolution.

BRIAN GREENE
Physicist & Mathematician, Columbia University; Author, The Fabric of the Cosmos; Presenter, three-part Nova program, The Elegant Universe

The Multiverse

The notion that there are universes beyond our own — the idea that we are but one member of a vast collection of universes called the multiverse — is highly speculative, but both exciting and humbling. It's also an idea that suggests a radically new, but inherently risky approach to certain scientific problems.

An essential working assumption in the sciences is that with adequate ingenuity, technical facility, and hard work, we can explain what we observe. The impressive progress made over the past few hundred years is testament to the apparent validity of this assumption. But if we are part of a multiverse, then our universe may have properties that are beyond traditional scientific explanation. Here's why:

Theoretical studies of the multiverse (within inflationary cosmology and string theory, for example) suggest that the detailed properties of the other universes may be significantly different from our own. In some, the particles making up matter may have different masses or electric charges; in others, the fundamental forces may differ in strength and even number from those we experience; in others still, the very structure of space and time may be unlike anything we've ever seen.

In this context, the quest for fundamental explanations of particular properties of our universe — for example, the observed strengths of the nuclear and electromagnetic forces — takes on a very different character. The strengths of these forces may vary from universe to universe and thus it may simply be a matter of chance that, in our universe, these forces have the particular strengths with which we're familiar. More intriguingly, we can even imagine that in the other universes where their strengths are different, conditions are not hospitable to our form of life. (With different force strengths, the processes giving rise to long-lived stars and stable planetary systems — on which life can form and evolve — can easily be disrupted.) In this setting, there would be no deep explanation for the observed force strengths. Instead, we would find ourselves living in a universe in which the forces have their familiar strengths simply because we couldn't survive in any of the others where the strengths were different.

If true, the idea of a multiverse would be a Copernican revolution realized on a cosmic scale. It would be a rich and astounding upheaval, but one with potentially hazardous consequences. Beyond the inherent difficulty in assessing its validity, when should we allow the multiverse framework to be invoked in lieu of a more traditional scientific explanation? Had this idea surfaced a hundred years ago, might researchers have chalked up various mysteries to how things just happen to be in our corner of the multiverse, and not pressed on to discover all the wondrous science of the last century?

Thankfully that's not how the history of science played itself out, at least not in our universe. But the point is manifest. While some mysteries may indeed reflect nothing more than the particular universe, within the multiverse, we find ourselves inhabiting, other mysteries are worth struggling with because they are the result of deep, underlying physical laws. The danger, if the multiverse idea takes root, is that researchers may too quickly give up the search for such underlying explanations. When faced with seemingly inexplicable observations, researchers may invoke the framework of the multiverse prematurely — proclaiming some or other phenomenon to merely reflect conditions in our bubble universe — thereby failing to discover the deeper understanding that awaits us.

DAVID GELERNTER
Computer Scientist, Yale University; Chief Scientist, Mirror Worlds Technologies; Author, Drawing Life

What are people well-informed about in the Information Age?

Let's date the Information Age to 1982, when the Internet went into operation & the PC had just been born. What if people have been growing less well-informed ever since? What if people have been growing steadily more ignorant ever since the so-called Information Age began?

Suppose an average US voter, college teacher, 5th-grade teacher, 5th-grade student are each less well-informed today than they were in '95, and were less well-informed then than in '85? Suppose, for that matter, they were less well-informed in '85 than in '65?

If this is indeed the "information age," what exactly are people well-informed about? Video games? Clearly history, literature, philosophy, scholarship in general are not our specialities. This is some sort of technology age — are people better informed about science? Not that I can tell. In previous technology ages, there was interest across the population in the era's leading technology.

In the 1960s, for example, all sorts of people were interested in the space program and rocket technology. Lots of people learned a little about the basics — what a "service module" or "trans-lunar injection" was, why a Redstone-Mercury vehicle was different from an Atlas-Mercury — all sorts of grade-school students, lawyers, housewives, English profs were up on these topics. Today there is no comparable interest in computers & the internet, and no comparable knowledge. "TCP/IP," "Routers," "Ethernet protocol," "cache hits" — these are topics of no interest whatsoever outside the technical community. The contrast is striking.

MAHZARIN R. BANAJI
Professor of Psychology, Harvard University

Using science to get to the next and perhaps last frontier

We do not (and to a large extent, cannot) know who we are through introspection.

Conscious awareness is a sliver of the machine that is human intelligence but it's the only aspect we experience and hence the only aspect we come to believe exists. Thoughts, feelings, and behavior operate largely without deliberation or conscious recognition — it's the routinized, automatic, classically conditioned, pre-compiled aspects of our thoughts and feelings that make up a large part of who we are. We don't know what motivates us even though we are certain we know just why we do the things we do. We have no idea that our perceptions and judgments are incorrect (as measured objectively) even when they are. Even more stunning, our behavior is often discrepant from our own conscious intentions and goals, not just objective standards or somebody else's standards.

The same lack of introspective access that keeps us from seeing the truth in a visual illusion is the lack of introspective access that keeps us from seeing the truth of our own minds and behavior. The "bounds" on our ethical sense rarely come to light because the input into those decisions is kept firmly outside our awareness. Or at least, they don't come to light until science brings them into the light in a way that no longer permits them to remain in the dark.

It is the fact that human minds have a tendency to categorize and learn in particular ways, that the sorts of feelings for one's ingroup and fear of outgroups are part of our evolutionary history. That fearing things that are different from oneself, holding what's not part of the dominant culture (not American, not male, not White, not college-educated) to be "less good" whether one wants to or not, reflects a part of our history that made sense in a particular time and place - because without it we would not have survived. To know this is to understand the barriers to change honestly and with adequate preparation.

As everybody's favorite biologist Richard Dawkins said thirty years ago:

Let us understand what our own selfish genes are up to, because we may then at least have a chance to upset their designs, something that no other species has ever aspired to do.

We cannot know ourselves without the methods of science. The mind sciences have made it possible to look into the universe between the ear drums in ways that were unimagined.

Emily Dickinson wrote in a letter to a mentor asking him to tell her how good a poet she was: "The sailor cannot see the north, but knows the needle can" she said. We have the needle and it involves direct, concerted effort, using science to get to the next and perhaps last frontier, of understanding not just our place among other planets, our place among other species, but our very nature.