RODNEY BROOKS is the director of the MIT Computer Science and Artificial Intelligence Laboratory. He is the author of Flesh and Machines: How Robots Will Change Us.
The thing I worry about most, that may or may not be true, is that perhaps the spontaneous transformation from nonliving to living matter is extraordinarily unlikely. We know that it has happened once, but what if we gain lots of evidence over the next few decades that it happens very rarely?
In my lifetime, we can expect to examine the surface of Mars and the moons of the gas giants in some detail. We can also expect to image extrasolar planets within a few tens of light-years to resolutions where we will be able to detect evidence of large-scale biological activity.
What if none of these observations indicates any life whatsoever? What does that do to our scientific belief that life arose spontaneously? It should not change it, but it will make it harder to defend against nonscientific attacks. And wouldn’t we be immensely saddened if we were to discover that there is a vanishingly small probability that life will arise even once in any given galaxy?
Being alone in this solar system will not be such a shock, but to be alone in the galaxy—or worse, alone in the universe—would, I think, drive us to despair and back toward religion as our salve.
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