We draw a picture of an infinite cylindrical bullet on the board. This is what mathematicians call homogeneity. Instructor indulges in 17th century skepticism here. There are lot's of interesting historical questions here about what a new idea is and how ideas come to be accepted. Now we think space is curved, just like a circle limit print, and we think of the curvature as the source of gravity.
Gravity is given by the shape of space.
Circle limit slide. Escher circle limit. In the case of the visual arts, in addition to illuminating, imitating, and interpreting reality, a few artists create a language of symbols for things for which there are yet to be words. Just as Sigmund Freud in his Civilization and Its Discontent s compared the progress of a civilization's entire people to the development of a single individual, I propose that the radical innovations of art embody the preverbal stages of new concepts that will eventually change a civilization. Whether for an infant or a society on the verge of change, a new way to think about reality begins with the assimilation of unfamiliar images.