So, I've been reading The Lies of Locke Lamora, by Scott Lynch. I'm sure everyone here is familiar with it. And I came across this line of dialogue: "What on earth do you mean?" I'm not sure how to handle such lines -- either in my own writing or in someone else's work. As far as I understood it, we are not on Earth. On the other hand, he doesn't capitalize "earth," so it's not a proper noun...in which case, he means the equivalent of "What on soil do you mean?" On another forum, I read some criticism of an author's use of "Adam's Apple," because the "Adam & Eve" mythos didn't exist in that world. How do you feel about such things? Does it take you out of the story, however briefly, or do you assume that these words are just substitutes for similar terms in these fantasy worlds? In other words, is Lynch just using "earth" in place of whatever the people of Camorr would call it? I'd love to hear the group consensus, if there is one. This kinda shit keeps me up at night!