> A complementary strategy is to search for technological signals from early distant civilizations that harnessed enough energy to make them detectable across the vast cosmic scale.

> Communication signals are not expected to be detectable across the universe, because the signal travel time would require billions of years in each direction and no participant would be patient enough to engage in such a slow exchange of information.

So effectively what we could search for is energy pollution from construction and transportation operations. Although it seems obvious in retrospect, it never occurred to me that intentional communication signals would not have the appropriate characteristics to be detectable across vast distances of space and time.