Time Travel

Tonight I was reading a comic to Quinn before bedtime. It's a Franklin Richard comic. Franklin as you may or may not know is the son of Mr Fantastic and the Invisible Woman from the Fantastic Four. This version isn't in continuity and has Franklin looking and acting like you would expect Calvin of Calvin and Hobbes to act (Hobbes as the voice of reason has been replaced with H.E.R.B.I.E., that robot that was part of the Fantastic Four back in the 70s who acts as a nanny to Franklin). Tonight's story involved time travel where a future Franklin comes back in time and hijinks ensue. While this is a concept I take for granted in stories, I actually had trouble explaining the idea of time travel it to Quinn. When I told him the story was about Franklin from the future coming back to now his first question was "What's the future?" While you may think this is a simple question, try answering it and explaining it to someone that doesn't understand the concept. I wasn't getting much traction explaining that it was simply some time that hasn't occurred yet. I was finally able to explain it using the clock and describing it as a time on the clock we haven't gotten to yet (the reference to a known time measurement was much better at explaining the concept than a nebulous reference to time itself). He also seemed to grasp the concept of him being older being a time in the future. Explaining the concept of time travel that appeared in the story proved more difficult "Well, that would be when the you, the older you in the future goes back in their time to something like now, which is the present or further back to our past, and they're here but still older..." I think he eventually got the concept despite my explanations.