Perhaps a better and more nuanced example can be found in Koreshanity.  This sect, which was prominent in the 19th century, believed that certain laws of optics and gravity were inverted.  They held that the whole of the universe was a hollow sphere, and we were living on the inner surface, with all of known space compressed into the center.  The thing is, if you actually invert certain rules of optics, you can form a consistent system the way they did - except that the results to a few crucial experiments contradict that.  If memory serves, they aren't results that you would come across in everyday life; only in conducting a specifically designed experiment to differentiate between Koreshanite optics and normal optics would you get the result.

I think that it is actually quite valuable to briefly entertain these wild theories, no matter how absurd they seem to us now.  The important part is that they can be tested and discarded once the data discredit them (conversely, if they turn out to be right, we learn something valuable.)  Koreshanity served to underline the fact that certain experiments were needed to prove that the laws of optics are the way they are, and without those experiments we would not have that data and there would be more ambiguity.