Dirac equation in the algebra of physical space Dirac equation in the algebra of physical space The Dirac equation, as the relativistic equation that describes spin 1/2 particles in quantum mechanics, can be written in terms of the Algebra of physical space (APS), which is a case of a Clifford algebra or geometric algebra that is based on the use of paravectors. The Dirac equation in APS, including the electromagnetic interaction, reads Another form of the Dirac equation in terms of the Space time algebra was given earlier by David Hestenes. In general, the Dirac equation in the formalism of geometric algebra has the advantage of providing a
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