Friday, November 07, 2003

Merkle and the case of the misleading metaphor

This recent article in The Scientist describes the daily dilemma facing scientists and science journalists: How do you describe what can't be seen? Well, thank goodness for the marvelous metaphor. If you took all the metaphors I've used over the years and stacked them up end to end, they would reach from Earth to the far side of Uranus and back. But all the good metaphors I've used could dance on the head of pin, their substance a thousand times thinner than the width of a human hair.

Which takes me back to nanotechnology. It's suffering from a chronic case of misleading metaphor. It's actually no joke, since much of the gooey fear surrounding the concept of self-replicating nanosystems stems from the use of a bad biotech analogy.

A few weeks ago, nanotechnology and cryptography poo-bah Ralph Merkle sat down with me to talk about a number of issues, including the need to alter the analogy.

"I think one of the fundamental things which is not understood at this point is that artificial replicating systems, manufacturing systems, are going to bear about as much resemblance to the biological variety as, say, a 747 bears to a duck," Merkle said.

He gave a simple example: When a biological cell replicates, the copy contains the DNA that describes its own blueprints. But these onboard blueprints would be unnecessary in an artificial system, where a human controller could broadcast instructions to the device and tell it to make a copy of itself. It's called a broadcast architecture, something that's well known among those who study self-replicating systems and it's "very nonbiological," Merkle said.

"It's inherently safe. You cut off the broadcasts, it stops working. You can flush these things down the toilet and they just twitch randomly once they're out in the sewage and the sludge. They just won't function."

Maybe we need a new word, he said. "Simply to use the word ("self-replication") is in and of itself misleading because what people think about are biological systems. They don't think about the broadcast architecture because they've never heard of it."

I was a little amazed that this brilliant theorist placed so much importance on the only skill that I allegedly have -- word choices. So, I asked him why metaphors matter at all.

"Look. This is a democracy, right? So, the basic ground rules are laid by what people understand," Merkle said. "As we get closer and closer to this technology it's important people understand what's going on, it's important we clarify these issues, so it's important we have an understanding of what it is we're talking about.

"If you're thinking about biological systems and trying to apply biological analogies while regulating and controlling a field which is totally nonbiological, you get a bad mismatch."

Change the analogy to reflect reality, and thus change public perception? Now, that's an idea I can put into my pipe and smoke.


No comments: