ABSTRACT
Our knowledge of the solar system would be quite limited if ancient astronomers had measured only the latencies, from dusk to first appearance, of the various planets. Given several centuries of such measures, astronomers could argue convincingly that the accumulated observations produced more confusion than order and that less refined measures of planetary performance might expose otherwise undiscoverable natural laws. A clear candidate for simplified data would be the presence or absence of a planet from the night sky, because this measure avoids the awkward problem of defining latencies for planets that do not appear. Armed with these binary performance measures, astronomers could produce an impressive array of statistics, but the heliocentric theory would most likely exist only in stargazers, eyes. Moreover, the call to reason, proclaiming that it would be better to obtain more than one response measure (e.g., latency and spatial position), might drown beneath a chorus of assertions that, like music from the spheres, drones out the common refrain: We can’t understand the performance of one variable, so why measure two?
