Time is our most familiar means of organizing thought and action, yet it is also the most illusive. Awareness of time as a perceptible one-way flow is a central facet of human consciousness. Everyone knows what time is but anyone would be hard pressed to define it. Is time unidirectional? Does it tick by at a constant rate? How do we measure it? How do we make sense of time before human experience? These are some of the mind-bending questions that Derek York introduces in his short and very readable collection of vignettes about time.