Only when he finally lowered his gaze did it occur to him that there was something unusual about the purple-hued horizon. Instead of the sky and the sea meeting in a straight line - as they ought to and always had before - the juncture between them curved, like the edge of an unimaginably big circle. It was such a strange sight, it took Eragon a half-dozen seconds to understand what he was seeing, and when he did, his scalp tingled and he felt as if the breath had been knocked out of him. "The world is round," he whispered. "The sky is hollow and the world is round."
by Christopher Paolini