This superb video by CGP Gray begins off as a seeming ode to the metric dimensional wonders of A4 paper and the entire bigger and smaller A-size papers that may be made by merely folding (or unfolding) a sheet. However, then issues get severely mind-expanding as they hold folding and folding that sheet of A4, all the way down to the quantum stage and past, after which again to the A4, and unfolding it out past the recognized universe.
You will by no means have a look at an A4 piece of paper the identical once more. Trippy and enlightening.
[Originally posted on Adafruit]