“No, Ellie, this is endless. After a dozen years you’ll find no sign of anything. You’ll argue that another Argus facility has to be built at a cost of hundreds of millions of dollars in Australia or Argentina to observe the southern sky. And when that fails, you’ll talk about building some paraboloid with a free-flying feed in Earth orbit so you can get millimeter waves. You’ll always be able to think of some kind of observation that hasn’t been done. You’ll always invent some explanation about why the extraterrestrials like to broadcast where we haven’t looked.”