A flop is a picture that mirror reverses the original scene. Some flops are reversed copies. For instance, mirror reversal is systematic with technologies that require contact between a template and an imprint surface. Other flops are just pictures that have undergone the operation of flopping. For example, a slide that is inserted backwards into a projector is a flop.

Ockham's razor is popularly phrased as a prohibition against multiplying entities beyond necessity. This prohibition should extend to the receptacle for these entities. To state my thesis more positively and precisely, both qualitative and quantitative parsimony apply to space, time, and possibility. All other things equal, we ought to prefer a hypothesis that postulates less space. Smaller is better. Admittedly, scientists are ambivalent about economizing on the void. They praise simplicity. Yet astronomers have a history of helping themselves to as (...) much empty space as they wish—staggering common sense with the vastness of the universe. This largesse is abetted by an aesthetic bias for sublime hypotheses. Whereas abductions based on beauty converge with parsimony, abductions based on the sublime diverge from parsimony. Awe stifles our inner accountant. Both types of abduction are popular. Both are dubious because we lack independent assurance that the universe is beautiful or sublime. The analogy between space and time supports an extension of parsimony to time. Uniformitarian geologists regarded time as a free resource. However, geologists and cosmologists must justify their postulation of an immense past. Possibility follows suit. Contrary to David Lewis, possible worlds should be minimized. Parsimony about possibilities provides a rationale for parsimony about absences. Absences are possibilities that are not actual. So proliferation of absences entails proliferation of possibilities. We should admit only those absences which do explanatory work. (shrink)