“The thing about television used to be that once you saw it, it was gone. It was disposable, and it was mostly dispensed with—the old signals, from what we used to watch, streaming out past the Oort Cloud, carrying Lancelot Link, Secret Chimp away into infinity. Suddenly, via YouTube links, those lost moments click back into view, as if a telegram from your great-grandfather were showing up in your e-mail.”