Links for 27th May 2009

Fresh from the clogged tubes of teh intarwubs…

  1. ARE VON NEUMANN PROBES ETHICAL?

    "Would a more advanced civilization, if they were also more ethically developed than we are (not hard to imagine) consider von Neumann probes a form of cancer and take steps to eradicate them? Worse, would they take punitive measures against any civilization irresponsible enough to set them loose? Maybe the reason no one else's von Neumann probes have arrived here in our solar system yet is because every enlightened species out there considers them a form of environmental pollution."

    Tagged with: von-neumannself-replicatingmachinesnanotechprobesFermiParadoxethicscivilisation

  2. Growing the Interstellar Probe

    "… a small interstellar probe could theoretically create a molecular computer which could then, upon arrival, create electronic equipment of the sort needed for observations. Think of a probe that gets around the payload mass problem by using molecular processes to create cameras and imaging systems not by mechanical nanotech but by inherently biological methods.

    A Von Neumann self-replicating probe comes to mind, but we may not have to go to that level in our earliest iterations. The biggest challenge to our interstellar ambitions is propulsion, with the need to push a payload sufficient to conduct a science mission to speeds up to an appreciable percentage of lightspeed. The more we reduce payload size, the more feasible some missions become — Koester was motivated to write by considering ‘Sundiver’ mission strategies coupled with microwave beaming."

    Tagged with: DNAorganicmolecularcomputerself-replicationinterstellarprobetheoryscience

  3. Turbo-evolution shows cod speeding to extinction

    "They have discovered a gene in cod, Pan I, that seems to govern the depth at which the fish live.

    Cod with the B form of Pan I live deeper down, except when they are on the shallow spawning grounds. Cod with the A form of the gene spend all their time closer to the surface.

    As the cod close to the surface are most likely to get caught, survival chances of fish with the A gene are only 8 per cent of those with the B gene. As a result, fish with the A gene are disappearing rapidly."

    Tagged with: sciencebiologyevolutioncodfisheriesselective-pressureenvironment

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