The theory is that an advanced civilization would give off significant heat waste products, which would be detectable in the infrared part of the RF spectrum. So a team of astronomers took at look at several hundred galaxies where there was “unusually extreme” mid-IR emissions. But the team found out that in the vast majority of these galaxies, the emissions were explainable by natural astrophysical processes. As Garrett said, “The original research at Penn State has already told us that such systems are very rare, but the new analysis suggests that this is probably an understatement, and that advanced Kardashev Type III civilizations basically don’t exist in the local universe. In my view, it means we can all sleep safely in our beds tonight—an alien invasion doesn’t seem at all likely!”
The Drake equation definitely implies that alien life is out there, simply because of the sheer vastness of the universe. But it does look unlikely that there are advanced civilizations nearby — we would’ve seen evidence. There’s also the possibility that advanced alien life is so advanced that they don’t really generate waste heat. Of course, more research is required, and astronomers will continue scouring the skies for evidence of life.