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This is one of the more compelling arguments to this. It at least certainly puts it into the bounds of possible. God did it, so there's a way that doesn't viola

This is one of the more compelling arguments to this. It at least certainly puts it into the bounds of possible. God did it, so there's a way that doesn't violate the laws of nature. I think this touches on my main beef with a specificity of Drexler's argument: He's written that biological systems are akin to a bit of a chaotic soup of machinery, while the APM systems he proposes are neat, organized; more like a factory. This begs the questions of #1: why nature hasn't built something like his APM factories, and #2: Why shouldn't we persue something more like biology vice his version of current-tech-but-smaller APM. Drexler uses Biology as an example of APM being feasible, but his vision is distinct from biology's.

abecedarius 4y ago
Those are the obvious first questions, yeah. I don't think #1 is very puzzling: can you expect a gradual continuous evolution from wiggly machines in solution, which communicate primarily by diffusion, and which must be robust to genetic variation, to a factory in hard vacuum? The path must be not just possible, but fitness-enhancing in each neighborhood (on the scale of the steps evolution took historically). In our history there was some evolution in this direction: introduction of compartments, active transport, complexes which cut out most of the diffusion step between related enzymes. But the compartments and the complexes are not qualitatively different. It seems a harder question why life stuck with protein/bone/enamel instead of discovering lighter and stronger densely-linked carbon structural materials. Maybe because bone is continually incrementally torn down and rebuilt? Re #2. I think anyone would agree that biology-style nanomachinery is interesting and promising. But factory-style opens up a whole new level of possibilities with orders of magnitude greater performance on multiple measures. People can pursue both! Flapping-wing flight had both scientific interest and potential applications in more-agile flying machines; that doesn't mean fixed-wing wasn't a much more strategic direction in the years around 1900.
- BlueTemplar 4y ago
  Spider silk is a keratin protein that is plenty light and strong...
  - abecedarius 4y ago
    Yes, the tensile strength is like steel but lighter. (And if you ever get gored by a rhino horn you aren't going to shrug and say "hey it's just protein.") But it's a long way from the limit of strength.

abecedarius 4y ago

Those are the obvious first questions, yeah. I don't think #1 is very puzzling: can you expect a gradual continuous evolution from wiggly machines in solution, which communicate primarily by diffusion, and which must be robust to genetic variation, to a factory in hard vacuum? The path must be not just possible, but fitness-enhancing in each neighborhood (on the scale of the steps evolution took historically). In our history there was some evolution in this direction: introduction of compartments, active transport, complexes which cut out most of the diffusion step between related enzymes. But the compartments and the complexes are not qualitatively different. It seems a harder question why life stuck with protein/bone/enamel instead of discovering lighter and stronger densely-linked carbon structural materials. Maybe because bone is continually incrementally torn down and rebuilt? Re #2. I think anyone would agree that biology-style nanomachinery is interesting and promising. But factory-style opens up a whole new level of possibilities with orders of magnitude greater performance on multiple measures. People can pursue both! Flapping-wing flight had both scientific interest and potential applications in more-agile flying machines; that doesn't mean fixed-wing wasn't a much more strategic direction in the years around 1900.

BlueTemplar 4y ago
Spider silk is a keratin protein that is plenty light and strong...
- abecedarius 4y ago
  Yes, the tensile strength is like steel but lighter. (And if you ever get gored by a rhino horn you aren't going to shrug and say "hey it's just protein.") But it's a long way from the limit of strength.