Because a lot of science is really about this non-existent world of thought experiments, our understanding of science must concern itself with worlds of the imagination as well as with worlds of reality. Imagination, rather than mere intelligence, is the truly human quality. And what better world of the imagination to start from than Discworld? Discworld is a consistent, well-developed universe with its own kinds of rules, and convincingly real people live on it despite the substantial differences between their universe's rules and ours. Many of them also have a thoroughgoing grounding in 'common sense', one of science's natural enemies.
Appearing regularly within the Discworld canon are the buildings and faculty of Unseen University, the Discworld's premier college of magic. The wizards are a lively bunch, always ready to open any door that has 'This door to be kept shut' written on it or pick up anything that has just started to fizz. It seemed to us that they could be useful ...
If we, or they, compare Discworld's magic to Roundworld science, the more similarities and parallels we find. Clearly, as the wizards of Unseen University believe, this world is a parody of the Discworld one. And when we didn't discover those, we found that the differences were very revealing. Science takes on a new character when you stop asking questions like 'What does newt DNA look like?' and instead ask 'I wonder how the wizards would react to this way of thinking about newts?'
There is no science as such on Discworld. So we have put some there. By magical means, the wizards on Discworld must be led to create their own brand of science, some kind of pocket universe' in which magic no longer works, but rules do. Then, as the wizards learn to understand how the rules make interesting things happen -rocks, bacteria, civilizations, we watch them watching ... well, us. It's a sort of recursive thought experiment, or a Russian doll wherein the smaller dolls are opened up to find the largest doll inside.