ABSTRACT
What is the ‘arrow of time’? There are various observable differences between past and future, but the laws of physics don't provide a direction in time. The ‘arrow of time’, if there is one, is whatever explains how a time-reversal invariant physics can produce so many asymmetries in our experience. This chapter considers the asymmetries of records, intervention, reference, and affect. It compares two approaches to providing an arrow of time: entropy and causation.
