In my atomic lecture notes it says

> 
> We can visualise an $l=0$ $s$-state as a spherical cloud expanding and contracting - breathing, as the the electron moves in space.
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> 
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Similarly in the video [enter link description here](https://youtu.be/Ziz7t1HHwBw?t=142)

it has an animation of the spherical harmonic growing and contracting in time.

How much can we read into these description of the orbitals - can we therefore infer that there is only intrinsic 'radial' motion for the electron in s-orbitals and hence they have $l=0$? Or are these results of the oscillations of the spherical harmonics in time unphysical since they are only in $\psi$ and not $|\psi|^2$?