Theodore Kneupper

Here are presented the essential features of what Mach considered the four important types or ideas of space and time. These are referred to as ‘perceptual,’ ‘geometrical,’ ‘physical space and time’ and ‘mathematical manifolds.’ Although the first is foundational, we consider how in Mach’s view each further type is in a sense a more general abstraction, freed from particular limiting characteristics of the preceding type. What is most significant is his view of the fourth, in which the most fundamental and essential feature of space is as a relation of immediacy and of time as a relation of mediacy. Some of the important implications of this are discussed, along with suggestions regarding their possible relevance to contemporary physics.