Seti (Search for Extraterrestrial Intelligence) astronomer Seth Shostak says instead of listening for radio waves and looking for biological signs in our search for life beyond Earth, we need to start trying to detect alien artificial intelligence. This is apparently a growing sentiment in the Seti community. It’s based on the idea that technology evolves much more quickly than humans.  Here’s a quote from Shostak:

“If you look at the timescales for the development of technology, at some point you invent radio and then you go on the air and then we have a chance of finding you,” he told BBC News.

“But within a few hundred years of inventing radio – at least if we’re any example – you invent thinking machines; we’re probably going to do that in this century.

“So you’ve invented your successors and only for a few hundred years are you… a ‘biological’ intelligence.”