Earlier my daughter and I were watching a trailer for 'How to Train Your Dragon'. At the end , the big logo pops up identifying the movie as being available in 3D. "Wow" I exclaim, it's in 3D.My daughter, thinks for a moment, then says "daddy, is there a 4D?" I calmly explain that yes, and that the fourth dimension is generally accepted as being Time. She thinks for another moment and adds "but what about the other ones?"As I had only been watching some you tube videos on the subject the previous evening, I had no problem in explaining the physics of addtitional dimensions to her.(you can see them here)I start by explaining that the first dimension is length, the second is width and the third is height. All combining to make the familiar three dimensional world we live in. In addition, it is possible that as you add dimensions, you start to experience parallel worlds through infinite dimensions.at this point, my wife leans over and says "she means 'are there any other movies?', you know, like Toy Story 3D...!"My daughter just looked at me. Maybe she'll be ready for that conversation next year.