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| Rearranging the elements with help from Mendeleyev and Pauling. | |
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Dateline: May 23, 2001
Nanotechnology can be qualitatively understood as an approach to alchemy that is based on the current model of matter. For more than 2000 years, the Aristotelian model of matter went relatively unquestioned in the western world. In this model, matter consisted of four elements: earth, air, fire and water. The variety of materials in existence was explained by the idea that the ratios of these elements within a material determined the form that the matter took. Based on this theory, the idea that one might rearrange the elements to create a desired material naturally followed. The arts of alchemy were early attempts to achieve this goal. In the last centuries, alchemy became more of a philosophy while its techniques were divided between chemistry, nuclear physics and various other disciplines.
In the 18th and 19th century, a far more accurate and productive model of the elements was finally developed. Lavoisier started the change with the discovery of a material that he called "oxygen" and began to arrange the other known elements into four groups. Dalton then proposed the importance of atomic masses, after which Mendeleyev noticed a pattern that resulted in the periodic table of the elements. Early in the 20th century, Pauling provided an accurate model of how these elements bond together to form molecules. These molecules can in turn interact by means of weak interactions. The chemical bonds and molecular interactions seem to be flawlessly explained by quantum mechanics, making our model of matter relatively complete.
With the new model being far more complex than the original one, the alchemist's goal of arbitrarily rearranging the elements became too confusing to pursue directly, until recently. During the last century, physicists and mathematicians have been ironing out the kinks in quantum mechanics. Chemists have found numerous ways to synthesize and characterize a plethora of molecules. Biologists have made enormous progress in understanding the molecular mechanisms and weak interactions that allow life to function. Meanwhile, the industrial revolution has provided us with machines, computers and other tools enabling further progress.
Our technology has now reached a point where the idea to more or less arbitrarily arrange the elements to create materials ranging from nanomachines to food is beginning to seem achievable. In 1959, Feynman translated the goals of alchemy into more modern terms, proposing that we miniaturize our tools for observing and manipulating matter until atomic precision is reached. In 1991, Drexler coined the term molecular nanotechnology referring to thorough, inexpensive control of the structure of matter. In the last decade, the concept of nanotechnology has been accepted by the scientific community and numerous organizations have been formed.
Unlike alchemy, nanotechnology is based on a more modern model of matter. Nanotechnology does not try to transmute elements as it is far cheaper to extract and purify elements or molecules from existing materials. Arranging the atoms in a material to get the desired elements where we want them is a far more economical approach but still requires significant effort and cooperation. Thus, nanotechnology is an interdisciplinary subject drawing from biology, chemistry, physics, engineering and computer science, to name a few. Each discipline contains an important piece of the puzzle, and as the puzzle is assembled we are witnessing remarkable advancements in our ability to economically control the structure of matter.
The latest examples include molecular imprinting, single molecule detection, DNA arrays and better sunscreens. However, with nanotechnology just now beginning, what might result is still a matter of imagination. For instance, the Drexlerian nanotech community is looking forward to a future where a nanorobotic assembler could be programmed to build just about any stable arrangement of atoms, including more assemblers. Others imagine quantum computers or long term life extension. Only time will tell whether these dreams will be realized or face the same fate as the philosopher's stone and the elixir of life. Regardless of whether the ultimate goal of atomic precision is reached, novel materials, methods and models are resulting from this second attempt at alchemy.