Thinking about scale in abstract terms is difficult. While it is easy to consider in terms of differences of size, the fact that applies in a host of different dimensions, and addresses, essentially, almost any aspect of variability, means thinking about the concept of scale generally very easily collapses into "big things and small things".

In this book, Zachary Horton approaches the topic through a series of specific examples - mostly related to the book "A Cosmic View" by Kees Boeke, and various films derived from it, most notably "Powers of Ten", produced by the Office of Charles and Ray Eames.

By keeping the focus on particular examples, and by examining the specific actions and decisions taken in order to produce them, Horton does an excellent job of bringing scale as a more general concept into view.

He ultimately argues that scale comes in two forms. The first, primary scale, is an ontological one. There are just some parts of the universe that differentiate themselves and have limitations on the ways that they can interact because of their differences. Phenomena at one scale either cannot impact on the other, or can only constrain because of those scalar differences.

The second form is medial scale, which is a process of creating a relationship between one scale and another that allows an observing/acting agent (us, basically), to make sense of it. The various examples explored by Horton are illustrations of this process of medial scale. The necessary use of different technologies, and the fact that choices must be made in the construction and use of these technologies, means that medial scales are inherently political. The enable the stabilisation (and thus perception and interaction) of certain things, and limit others. Horton refers tot his as a 'resolving cut', which follows Karen Barad's concept of an 'agential cut', if you know their work.

While there are some frustrating limitations in the text - most notably a tendency to elide over the role of the subject or agent in the process of mediation in the central chapters, and not really get to grips with it in final one where it's a core topic - this feels like a classic. It takes a new, crucial concept and makes available for study and more systematic discourse. That is vitally important work, and on that will have significant impact to come.

I came across this following a conference presentation of Horton's appearing in a Mastodon feed for me, I think. There has already been a whole conference dedicated to the topic, therefore, and so I've some catching up to do. But the different aspects of media theory, philosophy, and cognitive science that this text entangles make for compelling reader (at least for this reader).