froni How to Live Safely in a Science Fictionol Universe
Time travel
1. Any journin in whieh thc intcrval of limę esjwietheilh\ thc trawler is not cqual to thc interval ol limę ineasurabte by thosc not travclinj* with thcm.
2. Chronodicgctical mowment that crcatesa nontrivial. non-scniantic differcntial between thc inncr, pcrsonal time of thc trawler, and thc conventional time as agreed upon In ihe world-at-large.