Anachronology
Traveling through time.... it's been the stuff of science fiction for over a century, yes? But did you know the concept of individuals skipping over great periods of time goes back much, much further?
In the late 1800s, machines were the means by which people could find themselves freed from the constraints of the 4th dimension, but stories date back hundreds of years further. Hindu and Buddhist mythologies speak of people traveling into the realms of gods or wonders, only to return to the world hundreds of years later. In the Japanese fairy tale Urashima Taro, a fisherman is pulled into the deep and comes back 300 years later. They explored the possibility and mutability of time, the relative flow of years across different dimensions, and considered the effects of being exposed to traveling through space and time well before the first episodes of Doctor Who were even imagined.
Modern (ish) literature presented us with angels passing through time, and later, with the increasing inventiveness of the late 1800s age of industry, machines provided us a link into the future and to the past. With our increasing dependency on computerization, the possibilities of our consideration of what possibilities spanning the centuries might hold for us.
But the science and philosophy of traveling through time are not the alpha and omega of it. Time travel.... here's an experiment for you to try at home:
Think back to your earliest happy memory. Picture it all, each detail. Who were you with? What were you doing? Was there music? Was there food? Recall those details - the sounds, the sights, the flavors. Draw them into a focus, with all the clarity and resolution of the moment itself. Hold that moment. Freeze it in your thoughts. Feel it.
Or imagine something you'd like to do. Travel to Disneyworld, or slow dance with the love of your life, or so on - - create those same details, down to the last little bit. Own that reality. Fix it within your mind.
And just like that, you've traveled through time. It can be, in its own way, just that simple. Memories, hopes - these are the simplest and faintest manner in which we can burst free from time to time from time itself.
But as to physically tearing free and finding yourself in the past or the future.... now that's a story for another day. I'll see you there!