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Eliezer S. Yudkowsky <email@example.com>
>I heard someone pointing out the flaw in a commonly-used
>analogy. If the maximum size for assemblers is smaller than the minimum size
>for chemically powered cells, the analogy is invalid and that's that.
Cells are huge, cells are conglomerates containing thousands of factories, but who said anything about cells? Drexler made an analogy between nano machines and something that was the same size, Ribosomes. Ribosomes are machines that input digital information (messenger RNA) and raw materials (amino acids) and output a finished product (a protein). The analogy isn't perfect, a ribosome can't make anything, but it's not bad because it can make any protein and there are a hell of a lot of them.
A full rod logic nanocomputer with the power of a modern mainframe would be far larger than a ribosome of course, it would need to have about 150 billion atoms, a cube 1000 nanometers on an edge would do it, that's about as big as another machine, a mitochondria. A complete cell is about 20,000 nanometers in diameter and has 8000 times the volume.
John K Clark firstname.lastname@example.org
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