Time travel is a topic often explored in science fiction and fantasy.
Hard science fiction goes into the physics/chemistry/other tough to understand science to explain how time travel could be possible.
Soft science fiction may explain time travel through vague scientific means or just establishes that time travel is possible (without explanation) and the reader just accepts this fact.
Fantasy likes to use magical elements such as portals, spells, serums, so on and so forth to explain/utilize time travel.
While I personally have considered several time travel plots for my stories, I have yet to write one. I do, though, make weekly jokes about being from the future, being from the past, being a zombie, a vampire, a samurai - all which have the ability to time travel.
Time travel has been a fascinating idea for many writers and has been the premise of many books and I would like to explore here, my latest time travel scenario:
Amanda and I looking for pictures of kittens on the Google, hoping to find one cute kitten with an upset belly. This is not because we like to see kittens in pain (we hope that being cute outweighs the pained look) but because we wanted a picture to go on the cover of a journal called "angry tummy times" or something like that. Finding no pictures of kittens that would be acceptable for a pink bismuth advertisement, Amanda realizes that there is an untapped world out there for these such photos and by tapping into it we could become millionaires (or possibly just dollaraires but we didn't go into specifics). Amanda utilized the world of kittenomics to prove that kitten pictures would make money. I said, why don't we go into a time machine and ask John Locke about it. Then I realized that John Locke is a philosopher, not the creator of economics (that's Adam Smith) but I don't like changing plans on the fly, so we still went to see John Locke.
As we step out of the space time continuum, a surprised John Locke stares at us -- visitors from the future.
Me: John Locke! What is the principle of kittenomics?
John Locke: What?
Me: You know nothing!
Then Amanda and I jump back into the space time continuum. On they way back Amanda reminds me that the future is bright, and hands me my shades. We see Huey Lewis traveling back in time and wave.
As we land back into present day I tell Amanda a funny joke about fudz. She explains to me that fudz is lolspeak, I tell her I just made it up. She tells me that all of my thoughts are unoriginal and have already been plastered all over the internetz. I blame Huey Lewis and plan to give him the finger next time I travel through time.