There's not much to be added to the good arguments from Roger t.s., just three remarks:
- there are also illusions of memory (my study object) adding to the illusions of perception
- "some people are so open-minded that their brains start to fall out" (forgot the source of the ciatation) - Little Hawk, you do not seem to know what 'cardinal numbers' are. 1, 3, 5 are cardinal numbers, true, but so are 2, 4, 6, ...19,...,32,.... And you can measure the crop circle diameters in feet, meters, inches. Taking into account the unavoidable measurement inaccuracy , each conceivable crop circle on earth will have a diameter that is a cardinal number. So what?

Wolfgang

(Three new song circles have been found in the south of Germany. And for all three of them the number of members can be given by a cardinal number. That must have a deeper meaning)