[...] These questions about the possibility of time travel are still live questions, and are still discussed in the philosophical literature. What have received less attention are issues concerning the probability of time travel. The ‘Probability and Time Travel’ project headed by myself and Alastair Wilson investigates just these questions. For instance, if it’s definitely the case that something will stop you when you go back in time to kill your grandmother, and one of those things is having a stroke, does that mean that the chance of having a stroke when travelling in time is higher than it would be if you stayed at home? Is time travel hazardous to your health? If so, how hazardous is it?