Hypothetical travel into the past or future
![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/64/The_Time_Machine_–_Frontpage_Heinemann.png/780px-The_Time_Machine_–_Frontpage_Heinemann.jpg)
![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/64/The_Time_Machine_–_Frontpage_Heinemann.png/780px-The_Time_Machine_–_Frontpage_Heinemann.jpg)
Time travel is the hypothetical activity of traveling into the past or future. Time travel is a widely recognized concept in philosophy and fiction, particularly science fiction. In fiction, time travel is typically achieved through the use of a hypothetical device known as a time machine. The idea of a time machine was popularized by H. G....