The argument for both of the chapters can be summarized using the term “time is a social construct”, and Rosenberg and Grafton were trying to push forth the concept of using motives a social development to inform the cartographical decisions when constructing timelines, and how the construction and representations feedback into each other.

Although this might be slightly off-topic, the relationship between geography and time echos with a lot of the ancient philosophical discussions around categorial conceptualism and the “discovery” aspect of our access to intrinsic division and categories that govern human understanding and cognitions ( a.k.a. Kant & Kantian Conceptualism ). They’re both concrete, some-what “absolute” categories that are currently universally defined by people, yet when discussed from a humanities / digital humanities perspective, they’re the core to subjective interpretations. Time is constantly moving, and geographical identities contribute to (and are affected by) social-culture movements. It was interesting when they talked about accuracy associated with non-linear narratives and mapping potentials. On one hand, they’ve become “laws” that any representation and visualization created with data relevant to these two aspects should not be doubted or questioned in terms of graphical integrity. On the other hand, they are limiting our interpretations.

We use time as a method of interpreting the reasoning behind the history, to map our current position within a proposed narrative. Not only the cartography of it is influenced by our focus on what is important to consider in history, but also how technological advancement creates new discoveries that push the existing boundaries of time into new dimensions. Essentially, more is different.

Discus chronologicus’s pivoting arm considers the time from a multidimensional perspective (somewhat analogous to timezones). We’re used making correlations between time, geography and humanities in a fluid manner, but for the audience of these chronographies from ~150 years ago, the concept of understanding time as a tree with multiple branches rather than a single list of events requires these types of figurative and interactive interfaces, and reveals some rather interesting things about their method of justification and precision of spatial information.