If we map as a continuous motion an ionising electron (beginning its journey at n=1) in an H atom, a specific hyperbolic spiral appears (see animation). When we solve this spiral formula, we find that at regular intervals the spiral angles will cancel to give integer values (360°=4r, 360+120°=9r, 360+180°=16r, 360+216°=25r ... 720°=∞ ... formulas below).
As the orbital levels corresponding to the principal quantum number n^2 (4, 9, 16, 25 ...) naturally occur via this spiral geometry, then at those points where the angles cancel to give integers (360°, 360+120°, 360+180°, 360+216° ...) we can use the spiral perimeter (r = Bohr radius) to derive the transition frequency for that integer (n^2) level ......, the question then becomes, could quantization in the atom have geometrical origins?
https://en.wikiversity.org/wiki/Fine-structure_constant_(spiral)
In the animation the radius is mapped (during ionization), as the electron reaches each integer level, it completes 1 orbit (for illustration) then continues outward (actual velocity will become slower as radius increases).
https://en.wikiversity.org/wiki/Fine-structure_constant_(spiral)#/media/File:Alpha-hyperbolic-spiral.gif