How will life on Earth end? International nuclear bombardment? Another asteroid? Enslavement by aliens? The devouring of all of our resources by a Skynet-esque batch of self-replicating microscopic robots? You laugh, but a lot of people (including a batch of anti-science terrorists) believe our demise will come in the form of self-replicating nanobots. So let's take a look at whether such a thing could happen, and what we could do to stop it.

The Grey Goo Scenario

"Grey goo" is a term coined by Eric Drexler in his 1986 book about nanotechnology, Engines of Creation. In one section of the book, Drexler speculates about what could happen if we created self-reproducing "nanobots." If they got out of control, they could conceivably use the resources of the entire planet to replicate in an exponential manner akin to bacterial replication. Every living creature, every useful mineral, would be converted into more of the "gray goo."
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