<font color="yellow">"I don't think this particular effort will produce a true self-replicating machine; all they seem to be talking about is a machine which prioduces the parts for its own assembly from a pre-prepared feedstock"</font><br /><br />Good point. In this light we and all animal aren't truly self replicating either. We need pre-prepared proteins, fats, sugars etc. to survive and grow. Only plants and some microbes are truly self-replicating using just inorganic raw materials. Not even all plants, many have sophisticated symbiotic relationships with microbes, fungus, some even eat animals. To have self-replicating machine that needs preprocessed feedstock isn't such a bad deal to start with. It's a bullet proof safe mechanism to avoid the unlikely but possible catastrophe stevehw33 described.<br /><br />First truly self-replicating machine probably isn't a single machine but a system of machines. A long and complex process starting from ore-collectors ending to assembly line, mimicking the way we build things. It might consist of numerous special robots, one mining, other transporting, third assembling. Or maybe there could be just one universal model that is able to use tools. This system would have many critical points suitable for human control to prevent disasters. <br /><br />Common necessity for both above systems is power. If the machines are dependent on external power grid their riot would end by flipping a switch. But if they are capable of, say, building solar cells to power themselves then ... we apply operation Dark Storm and hope for the best <img src="/images/icons/wink.gif" /><br /><br />It's relatively easy to imagine fully automated system making metals, ceramics and even semiconductors. What about plastics, rubber, oils etc, it's difficult to imagine a functioning robots made without those. So I guess the new machine overlords have to either learn how to drill oil or do farming.