Size in Time

Walker's proposed new physical attribute of objects: the depth of an object's minimal construction history, "rolled up as a stack structure in the present." Evolved objects are larger in time than in space, and the deeper they are, the more abstract/virtual they look (language, culture, the technosphere). For molecules this is the assembly index, measurable by spectrometry; for everything else it is extended by analogy. Her headline consequences — Earth is "the largest object in the universe", the technosphere the newest and oldest thing — are claims about size in time, not space. Distinct from clock time: she calls it construction, causal or functional time.