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David Deutsch
IF CONSCIOUSNESS TERRY IS ENERGY, THEN I SUPPOSE YOU DON’T SEJNOWSKI Fifty years is about the time it takes for NEED PROOF THAT breakthroughs to occur that you cannot IT SURVIVES DEATH, anticipate. The structure of DNA was discovered in 1953 and the human genome BECAUSE PROOF was sequenced in 2003. I once asked Francis Crick if back then he thought the human ALREADY EXISTS genome would be sequenced in his lifetime.
to prove that there is (or isn’t) an afterlife, I met a Duke University professor, Gerry Nahum, who would very much like to undertake a consciousness-weighing project of his own (offing not sheep nor men but leeches). Though he taught gynaecology and obstetrics, Nahum has a background in thermodynamics and information theory and has even worked out a 25-page proposal of exactly how to do it, if only someone will fund him the $100,000 he estimates it will cost. If consciousness is energy, then I suppose you don’t need proof that it survives death, because proof already exists: the First Law of Thermodynamics – energy is neither created or destroyed. Though it’s hard to take much comfort from this. Who wants to spend eternity as a blip, a gnat’s fart, of disordered energy, with no brain at your disposal to help you remember or imagine or solve the Sunday crossword? What would it be like? Would there even be a be? Nahum uses the analogy of the computer: perhaps you’d be the operating system, stripped of its programs and interfaces. Heaven as the back of the closet where the broken-down Dells and Compaqs go. If we are to eventually have our answer, our proof, it will no doubt come to us courtesy of quantum theory, or whatever takes its place. Few of us will understand it well enough to take much comfort, however, if indeed comfort is what it offers. I recommend that you enjoy life without worrying about the “after” bit, and keep in mind that one day altogether too soon, bad luck or genetics will hand you the answer. In the meantime, be nice to sheep. ● Mary Roach is a writer based in San Francisco. She is the author of Spook: Science tackles the afterlife (W. W. Norton, 2006) and Stiff: The curious lives of human cadavers (Thorndike, 2004) www.newscientist.com
061118_F_7_Die 69
He said it never occurred to him. Crick also worked on consciousness, which was not solved during his lifetime. How far will we get in 50 years? By then we will have machines that pass the Turing test. However, this is a weak test that does not get at the harder problem, which is to understand how the brain creates consciousness. To crack this we must first understand unconscious processing, which does most of the heavy lifting for us. I suspect that when we start to make progress with this the problem of consciousness will, like the Cheshire cat, disappear, leaving only a smile in the air. Terry Sejnowski is head of computational neurobiology at the Salk Institute and a professor of biology at the University of California, San Diego
DAVID DEUTSCH On the experimental side, the construction of a working, general-purpose quantum computer is what we are all hoping for. With luck, and with the help of recent theoretical advances, this may take a lot less than 50 years. It would be important not so much for its applications (which would be significant but rather specialised, such as code-breaking and the simulation of quantum-mechanical systems) but because it would be an entirely new way of harnessing nature. Some physicists, myself included, believe that even present-day quantum technology relies on the sharing of informationprocessing tasks between parallel universes. On the theoretical side, I expect a further major integration between physics and information science. The key breakthrough would be the development of a quantum theory of construction – the general theory of what, according to the laws of physics, can or cannot be built and with what resources. If only we had such a theory today: it could tell us how hard it will be to build a quantum computer. David Deutsch is professor of physics at the University of Oxford
NATHAN MYHRVOLD Applied physics will be revolutionised in the next 50 years in ways we never thought possible, by advances in metamaterials, substances whose intricate synthetic structures enable them to transcend many of the limitations of natural materials. From the Stone Age to modern times, technology has relied exclusively on materials whose properties are defined by the natural elements from which they are composed. In recent years researchers have used nanotechnology and quantum mechanics to engineer a new class of materials bearing a far richer internal structure. Some of these metamaterials can perform feats that would have seemed miraculous a few decades ago, such as optics that have a negative index of refraction and thus bend light in the opposite direction to natural materials such as glass. We can now envision telescopes and microscopes that beat the diffraction limit, resolving objects that are far finer than half the wavelength of light. Last month, scientists at Duke University in North Carolina and Imperial College London unveiled a “cloak of invisibility” made from a tunable metamaterial that bends microwaves around whatever it surrounds. These are the earliest indications of what is bound to be a renaissance in materials science. Metamaterials will completely change the way we approach optics and nearly every aspect of electronics. Just as solid-state devices replaced vacuum tubes, metamaterial optics will make glass lenses a quaint artefact of an obsolete era. Other metamaterials designed to shepherd electrons more precisely and efficiently could solve the heat and scaling problems that plague microcircuitry. The greatest impacts of these materials, though, are likely to come from inventions that no one has thought of yet. Nathan Myhrvold is former chief technology officer at Microsoft and co-founder of the invention company Intellectual Ventures in Bellevue, Washington
18 November 2006 | NewScientist | 69
10/11/06 12:12:11 pm
to prove that there is (or isn’t) an afterlife, I met a Duke University professor, Gerry Nahum, who would very much like to undertake a consciousness-weighing project of his own (offing not sheep nor men but leeches). Though he taught gynaecology and obstetrics, Nahum has a background in thermodynamics and information theory and has even worked out a 25-page proposal of exactly how to do it, if only someone will fund him the $100,000 he estimates it will cost. If consciousness is energy, then I suppose you don’t need proof that it survives death, because proof already exists: the First Law of Thermodynamics – energy is neither created or destroyed. Though it’s hard to take much comfort from this. Who wants to spend eternity as a blip, a gnat’s fart, of disordered energy, with no brain at your disposal to help you remember or imagine or solve the Sunday crossword? What would it be like? Would there even be a be? Nahum uses the analogy of the computer: perhaps you’d be the operating system, stripped of its programs and interfaces. Heaven as the back of the closet where the broken-down Dells and Compaqs go. If we are to eventually have our answer, our proof, it will no doubt come to us courtesy of quantum theory, or whatever takes its place. Few of us will understand it well enough to take much comfort, however, if indeed comfort is what it offers. I recommend that you enjoy life without worrying about the “after” bit, and keep in mind that one day altogether too soon, bad luck or genetics will hand you the answer. In the meantime, be nice to sheep. ● Mary Roach is a writer based in San Francisco. She is the author of Spook: Science tackles the afterlife (W. W. Norton, 2006) and Stiff: The curious lives of human cadavers (Thorndike, 2004) www.newscientist.com
061118_F_7_Die 69
He said it never occurred to him. Crick also worked on consciousness, which was not solved during his lifetime. How far will we get in 50 years? By then we will have machines that pass the Turing test. However, this is a weak test that does not get at the harder problem, which is to understand how the brain creates consciousness. To crack this we must first understand unconscious processing, which does most of the heavy lifting for us. I suspect that when we start to make progress with this the problem of consciousness will, like the Cheshire cat, disappear, leaving only a smile in the air. Terry Sejnowski is head of computational neurobiology at the Salk Institute and a professor of biology at the University of California, San Diego
DAVID DEUTSCH On the experimental side, the construction of a working, general-purpose quantum computer is what we are all hoping for. With luck, and with the help of recent theoretical advances, this may take a lot less than 50 years. It would be important not so much for its applications (which would be significant but rather specialised, such as code-breaking and the simulation of quantum-mechanical systems) but because it would be an entirely new way of harnessing nature. Some physicists, myself included, believe that even present-day quantum technology relies on the sharing of informationprocessing tasks between parallel universes. On the theoretical side, I expect a further major integration between physics and information science. The key breakthrough would be the development of a quantum theory of construction – the general theory of what, according to the laws of physics, can or cannot be built and with what resources. If only we had such a theory today: it could tell us how hard it will be to build a quantum computer. David Deutsch is professor of physics at the University of Oxford
NATHAN MYHRVOLD Applied physics will be revolutionised in the next 50 years in ways we never thought possible, by advances in metamaterials, substances whose intricate synthetic structures enable them to transcend many of the limitations of natural materials. From the Stone Age to modern times, technology has relied exclusively on materials whose properties are defined by the natural elements from which they are composed. In recent years researchers have used nanotechnology and quantum mechanics to engineer a new class of materials bearing a far richer internal structure. Some of these metamaterials can perform feats that would have seemed miraculous a few decades ago, such as optics that have a negative index of refraction and thus bend light in the opposite direction to natural materials such as glass. We can now envision telescopes and microscopes that beat the diffraction limit, resolving objects that are far finer than half the wavelength of light. Last month, scientists at Duke University in North Carolina and Imperial College London unveiled a “cloak of invisibility” made from a tunable metamaterial that bends microwaves around whatever it surrounds. These are the earliest indications of what is bound to be a renaissance in materials science. Metamaterials will completely change the way we approach optics and nearly every aspect of electronics. Just as solid-state devices replaced vacuum tubes, metamaterial optics will make glass lenses a quaint artefact of an obsolete era. Other metamaterials designed to shepherd electrons more precisely and efficiently could solve the heat and scaling problems that plague microcircuitry. The greatest impacts of these materials, though, are likely to come from inventions that no one has thought of yet. Nathan Myhrvold is former chief technology officer at Microsoft and co-founder of the invention company Intellectual Ventures in Bellevue, Washington
18 November 2006 | NewScientist | 69
10/11/06 12:12:11 pm