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Peter Cochrane's Hard Drive 1997 There's nothing to the universe WE live in a physical domain where things appear to be solid, of manageable dimensions and spacing comparable with the human form and mind. Broadly speaking, everything we see, feel, hear, smell, and taste, is bounded by about 12 orders of magnitude. However, travel into outer space, or down into the depths of atoms and the dominant material is nothing, just emptiness; solidity is hard to find. There are many more orders of magnitude difference spanning these domains. For us this is counterintuitive as our senses and practical experience lead us to perceive and think in terms of a solidity, of finite space and physical limits to what we might do. The smallest thing we can see with the naked eye is only slightly smaller than 10-4 m (0.0001m), and with an optical microscope around 10-7 m. Using an atom smasher the smallest objects detected are w and z particles of about 10-17 m diameter. Conversely the largest man made objects, and those of nature, range in the tens and thousands of metres. At the other extreme, the largest detected clusters of galaxies in the universe span some 10m diameter. From the smallest to the largest the span is some 42 orders of magnitude, compared with our very limited 12 or so. So what percentage of space is more than nothing? Well it depends on precisely how we form an estimate, but the critical density of the universe is about three hydrogen atoms per cubic metre. So on average, all space is very empty. In terms of volume there is a factor of 10 of emptiness - that is 1,000,000,000 parts of nothing and only 1 part of something. Clearly, nothing (emptiness) dominates, and we have a lot of vacant space to exploit. This has important implications for the future of everything. For example, we currently minimise the weight of aircraft, cars and bridge structures by removing material from areas that do not experience significant stress. In the crudest realisations we just drill or mill out large holes with rounded profiles to reduce the incidence and risk of stress cracks. But if we could manipulate the space in materials more efficiently, at an atomic and molecular level, then we could perhaps reduce the weight of an aircraft by 90 per cent and yet make it much stronger. Every piece of technology has to live with and accommodate material imperfections that limit physical strength, bit storage, processing, and display. If we could eradicate imperfections we would see dramatic performance improvements, with reductions in manufacturing cost, wasted material, energy and time. If we could build electronic and photonic devices an atom at a time we might see another technological leap on a par with the change from the thermionic valve to the transistor. The perfecting of nanotechnology to build devices an atom at a time, to get their type and geometry precise, relative to their peers, may be a vital step for the future. It looks feasible to enhance many of our technologies at least a millionfold over the projections we currently hold to be true. We also stand to discover many new and unthought of properties. For example, every atom could be engineered to represent at least one bit, and so atoms equal bits. Peter Cochrane holds the Collier Chair for the Public Understanding of Science & Technology at the University of Bristol. His home page is: |
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