The concept of opposites is described to children as representing the maximum dissimilarity possible between two things that share a relation—hot and cold are opposites sharing a relation in temperature, approaching and receding are opposites sharing a relation in proximity over time, etc. So when some of these children become adults and find themselves contemplating the universe while in transit to work, they might conclude that no planet could be more different from Earth than a planet that was in every way Earth’s opposite. Let’s visit such a planet to find out why this view is flawed. Briefly, first, nomenclature: enclosing a word in / represents its opposite.

One of the most immediate differences a traveler to /Earth/ would notice is the necessity of wearing bizarre accoutrements consisting, crucially, of a downward-pointing—and always ignited—rocket. This, to counteract the effects of /gravity/. Walking in the Pacific Desert under a heavy snowrise, a native of Earth would quickly discover that maneuvering through this new planet is not nearly as difficult as they had supposed. Familiar with the concept of opposites, and well acquainted with the nature of things on the reference planet, the traveler would be able to predict the outcome of behaviors. For example, seeing a house in the distance, they would know that walking towards it would only make it recede, and that it would be brought near by walking in the opposite direction.

This ability to predict strikes me as being very much at odds with the notion of maximum dissimilarity. True dissimilarity would make no accommodation for understanding. The crux is owed to the limitation imposed by the condition that the two things being compared share a relation. This limits you to a 2-dimensional spectrum, a line. Lukewarm is the midpoint of one such line, between the extremes of hot and cold. Removing the relation restriction opens myriad options. The possibilities no longer march single file, but break away chaotically in all directions, vaguely contained by the suggestion of a sphere. Certainly, a planet wherein walking towards a house resulted not in its recession but in its transformation into the sculpture of a human head would be a planet more dissimilar to Earth than /Earth/.