This really tells us extremely little about advanced civilizations, beyond that we haven&#x27;t seen them doing a few variations on a very specific activity—harnessing all the stellar radiation in their galaxy.<p>There are huge number of assumptions based on that idea.  A fundamental one is that a civilization in a relativistic universe would grow to densely inhabit a galaxy.  Another is that they would <i>need</i> that much energy.  Another is that even if they <i>did</i> have need for that much energy, they&#x27;d bother collecting EM radiation from stars.<p>That third is an interesting one to me.  Now, you could muck up the night sky for the entire Milky Way, or you could, with Sufficiently Advanced Technology (tm), annihilate a total of 10 Jupiter-masses a year across the whole galaxy.  For your average star system, that&#x27;s extracting energy from 1.1 billion kg of mass a year, or roughly what NYC&#x27;s garbage collection services dispose of every two weeks.<p>Pondering that, I suspect it&#x27;s the wrong idea to imagine that a very advanced civilization, something we can only understand in the dimmest sense, would be constrained by something as specific as stellar energy emissions.