Nonetheless, if Warwick is already invoking The Matrix when speaking about cyborg technology, Lipson isn’t quite ready to talk The Terminator when it comes to self-replication. All the same, he says, “I think the idea could extend in the future to machines that are made of many more smaller modules — sort of high-resolution replication.” The better, perhaps, for the machines to more easily mimic human appearance as they reproduce within our ranks — and plot our destruction.
While the technology itself is still new, people have been theorizing and fantasizing about out-of-control self-replication — especially when it comes to nanotechnology — for a while now. In 1998, Wil McCarthy, an aerospace engineer and sci-fi writer, wrote a book, Bloom, in which planet Earth was overrun by “technogenic life” — ravenous microscopic machines that devour the ecosystem in short order as they reproduce infinitely.
It’s not as crazy as it sounds. Bloom was based on science: the “gray goo” theory — so named for what the Earth would eventually be enveloped in, as these tiny, tiny robots reproduced ever faster — first put forth by K. Eric Drexler, the “father of molecular nanotechnology,” in 1986.
Drexler himself has since backed off from some of these more fantastical scenarios. “The ‘gray goo’ scare stories that have been circulating for the past 20 years or so are based on a distortion of some ideas in my first book on the subject, Engines of Creation,” he says. “These ideas became obsolete a few years later. People sometimes picture advanced nanotechnology as being about breeding nanobugs, [but] there’s no reason to try to make anything like that. Nanomanufacturing will [instead] be based on factories, and current designs look like desktop boxes with fans, power cords, and little rubber feet. These boxes would contain a lot of equipment remarkably similar to what you’d see in a modern automated factory, but with the smallest gears, conveyors, and so on being near the molecular size scale.”
“When people write about nanotechnology, they have a tendency to assume, incorrectly, that it can do anything,” says McCarthy. “But just because the machines are microscopic in size doesn’t mean that the laws of physics are any different for them. They still have to consume energy, they still have to obey certain conservation laws. Are there self-replicating nanomachines? No. Are there likely to be in the next 10 years? No. Is it a good idea for people to do? I don’t know.”
So breathe easy. For now. Could it ever happen? “I think, on a 15-year horizon, things like that will start to become possible, although difficult,” says McCarthy. Even then, though, “I don’t think it could happen by accident. I don’t think something like that could get out of control, unless a lot of people made a lot of very bad choices along the way. I don’t worry about it in that sense.”
And even if it was possible to unleash this world-devouring “ecophagy” by accident, says McCarthy, “there are a lot of ways to prevent the scenario from occurring. One of the ways that Drexler proposed was just to require the nanomachines to eat some particular food that’s not found in nature: some artificial amino acid or something; if they find themselves in an environment where that chemical is absent, they shut down.”