We are familiar with the concept of time: past, present, and future. We make many inferences about time. It might seem simple, but if we start thinking about time, we can get very confused. ‘The future and the past: is time real?’ examines time in relation to logic. One particularly puzzling thing is: time seems to flow. How can time change? Time measures the rate at which everything else changes. This problem is central to several interesting time conundrums. Every situation comes with an associated collection of earlier and later situations. Where does space come into thoughts about time? Space does not flow in the same way that time does.