The Fabric of the Cosmos the book, such as discussions revolving around classical physics, quantum mechanics, and cosmological physics. Chapter 2, "The Universe and the Bucket", features space as its key point. The question posed by Greene is this: "Is space a human abstraction, or is it a physical entity?" The key thought experiment is a spinning bucket of water, designed to make one think about what creates the force felt inside the bucket when it is spinning. The ideas of Isaac Newton, Ernst Mach, and Gottfried Leibniz on this thought experiment are discussed in detail. Chapter 3, "Relativity and the Absolute", focuses on spacetime.
Interaction technique line and direct manipulation user interfaces. While interaction techniques are typically technology-, platform-, and/or implementation-dependent (see #level of granularity above), human-computer or human-information interactions can be characterized at higher levels of abstraction that are independent of particular technologies and platforms. At such levels of abstraction, the concern is not precisely how an interaction is performed; rather, the concern is a conceptual characterization of what the interaction is, and what the general utility of the interaction is for the user(s). Thus, any single interaction pattern may be instantiated by any number of interaction techniques, on any number of different technologies and