Hello, CGP Grey here, with a sheet of A4 paper, which is a special aspect ratio that remains the same shape when doubled in size to A3, or cut in half to A5, into quarters to A6 or eighths to A7. It's such a hypnotizing effect, that you can keep going...down...down...down...to the size of a bee, the size of the organs of the bee, the cells of those organs, the molecules of those cells. Just ten doublings down and the lights go out, as we hit the limits of anything that could be called human vision. Turning on magic science vision, we see DNA, the instructions of life, and the atoms that make it up. Falling through the electron shell and then twice as many doublings in scale as we've already gone we find the nucleus of the atom, tightly packed protons and neutrons, each made of three quarks, at which point we fall down, down and down and down to the basement of existence to reach the Planck length, the smallest distance the universe can contain, which hints at a reality pixel, which we probably shouldn't think about. At this scale, at the bottom of reality, there is...nothing here, except for the violin on which I shall play you a sad little tune.