This is the Discworld, which travels through space on the back of four elephants, which themselves stand on the shell of Great A'Tuin, the Sky Turtle.
Once upon a time, such a universe was considered unusual and possibly impossible. But then, it used to be so simple once upon a time, because the universe was full of ignorance all around. The scientist panned through it like a prospector crouched over a mountain stream, looking for the gold of knowledge among the gravel of unreason, the sand of uncertainty, and the little whiskery eight-legged swimming things of superstition. Occasionally, he would straighten up and say things like, "Harrah! I've discovered Bo's Third Law," and everyone knew where they stood. But the trouble was that ignorance became more interesting, especially big, fascinating ignorance about huge and important things like matter and creation. People stopped patiently building their little houses of rational sticks in the chaos of the universe and started getting inte…