Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space, generally using a theoretical invention known as a time machine. Time travel is a widely recognized concept in philosophy and fiction, particularly science fiction, but also features in history and religion. In these contexts, it incorporates the idea of a time traveler, either an individual or a time-traveling vehicle, that can perambulate freely or near-freely through time. The concept has been popularized by fiction, particularly H.G. Wells' 1895 novel The Time Machine. The term "time travel" was coined by Wells in this book. Time travel is translated to Hebrew as נסיעות בזמן. In French, it is voyage dans le temps, in German Zeitreisen, in Spanish viaje en el tiempo, and in Japanese 時空を超える (jikū o koeru). Key contextual information includes the distinction between time travel to the future and time travel to the past. Traveling to the future is theoretically possible, as it can be achieved by time dilation through near-light-speed travel or by gravitational time dilation. However, traveling to the past is considered to be unfeasible, as it violates the second law of thermodynamics and the principle of causality. Despite this, the concept remains a popular subject of speculation and fiction.
Hypothetical travel into the past or future
Time travel is the hypothetical activity of traveling into the past or future. Time travel is a concept in philosophy and fiction, particularly science fiction. In fiction, time travel is typically achieved through the use of a device known as a time machine. The idea of a time machine was popularized by H. G. Wells's 1895 novel The Time Machine.