There must be more life than intelligence (assuming that all intelligent things are alive). Even if you think that the solution to the Fermi paradox is that intelligence is an evolutionary dead end, using our own planet as an example, you would have had 3.5 billion years to observe life prior to the emergence of intelligence.
That's why work by MIT's Sara Seager is so exciting (and brilliant). Instead of looking for signals (that we might not notice as signals) or even for artifacts, Seager is looking for chemical signatures of life, period. These techniques will limit us to a smaller set of closer stars, but a) again, life must be more common than intelligence and b) we actually know what we're looking for. In this case, biosignature gases - gases that cannot be in the atmosphere unless there's some non-geologic process actively replacing them. On Earth, that's oxygen. On terrestrial planets, another one is ammonia. That "smaller set" of stars that she's looking at - all M-class, in line with Seager's technique - is still 30,000 systems.
And most excitingly, she kind of puts odds on it: she plugged values into the Drake equation and, based on the actual data that her project will be generating, she thinks there will be two detections of alien life in the next decade. Not everyone gets to build a spreadsheet that translates budget numbers and processor speed into number of projected alien ecosystems discovered.
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