SETI Senior Astronomer Seth Shostak argues that SETI might be more successful if it shifts the search away from biology and focuses squarely on artificial intelligence. Shostak sees a clear distinction between life and intelligence: he says we should be searching for extraterrestrial machines.

The window between a society’s technological birth and its shift to AI is amazingly small. “Once any society invents the technology that could put them in touch with the cosmos, they are at most only a few hundred years away from changing their own paradigm of sentience to artificial intelligence,” he says. Because artificial sentience would almost inevitably outlast and outperform its fleshy, needy predecessors, Shostak concludes that any aliens we detect will be machines.

“Machines have … no obvious limits to the length of their existence, and consequently could easily dominate the intelligence of the cosmos. In particular, since they can evolve on timescales far, far shorter than biological evolution, it could very well be that the first machines on the scene thoroughly dominate the intelligence in the galaxy.”

The machines would require two primary resources: energy to operate with and materials to maintain or advance their structure. Because of these requirements, Shostak thinks SETI ought to consider expanding its search to the energy- and matter-rich neighborhoods of hot stars, black holes and neutron stars, and to Bok globules (dense regions of dust and gas that produce multiple-star systems at around negative 441 degrees Fahrenheit, and are more efficient, since cooling is not required).